aboutsummaryrefslogtreecommitdiff
path: root/src
diff options
context:
space:
mode:
Diffstat (limited to 'src')
-rw-r--r--src/backend/access/index/indexam.c3
-rw-r--r--src/backend/access/nbtree/nbtcompare.c273
-rw-r--r--src/backend/access/nbtree/nbtpreprocesskeys.c631
-rw-r--r--src/backend/access/nbtree/nbtree.c196
-rw-r--r--src/backend/access/nbtree/nbtsearch.c130
-rw-r--r--src/backend/access/nbtree/nbtutils.c756
-rw-r--r--src/backend/access/nbtree/nbtvalidate.c4
-rw-r--r--src/backend/commands/opclasscmds.c25
-rw-r--r--src/backend/utils/adt/Makefile1
-rw-r--r--src/backend/utils/adt/date.c46
-rw-r--r--src/backend/utils/adt/meson.build1
-rw-r--r--src/backend/utils/adt/selfuncs.c491
-rw-r--r--src/backend/utils/adt/skipsupport.c61
-rw-r--r--src/backend/utils/adt/timestamp.c48
-rw-r--r--src/backend/utils/adt/uuid.c70
-rw-r--r--src/include/access/amapi.h3
-rw-r--r--src/include/access/nbtree.h34
-rw-r--r--src/include/catalog/catversion.h2
-rw-r--r--src/include/catalog/pg_amproc.dat22
-rw-r--r--src/include/catalog/pg_proc.dat27
-rw-r--r--src/include/utils/skipsupport.h98
-rw-r--r--src/test/regress/expected/alter_generic.out10
-rw-r--r--src/test/regress/expected/btree_index.out41
-rw-r--r--src/test/regress/expected/create_index.out183
-rw-r--r--src/test/regress/expected/psql.out3
-rw-r--r--src/test/regress/sql/alter_generic.sql5
-rw-r--r--src/test/regress/sql/btree_index.sql21
-rw-r--r--src/test/regress/sql/create_index.sql63
-rw-r--r--src/tools/pgindent/typedefs.list2
29 files changed, 2889 insertions, 361 deletions
diff --git a/src/backend/access/index/indexam.c b/src/backend/access/index/indexam.c
index 55ec4c10352..219df1971da 100644
--- a/src/backend/access/index/indexam.c
+++ b/src/backend/access/index/indexam.c
@@ -489,7 +489,8 @@ index_parallelscan_estimate(Relation indexRelation, int nkeys, int norderbys,
if (parallel_aware &&
indexRelation->rd_indam->amestimateparallelscan != NULL)
nbytes = add_size(nbytes,
- indexRelation->rd_indam->amestimateparallelscan(nkeys,
+ indexRelation->rd_indam->amestimateparallelscan(indexRelation,
+ nkeys,
norderbys));
return nbytes;
diff --git a/src/backend/access/nbtree/nbtcompare.c b/src/backend/access/nbtree/nbtcompare.c
index 291cb8fc15d..4da5a3c1d16 100644
--- a/src/backend/access/nbtree/nbtcompare.c
+++ b/src/backend/access/nbtree/nbtcompare.c
@@ -58,6 +58,7 @@
#include <limits.h>
#include "utils/fmgrprotos.h"
+#include "utils/skipsupport.h"
#include "utils/sortsupport.h"
#ifdef STRESS_SORT_INT_MIN
@@ -78,6 +79,51 @@ btboolcmp(PG_FUNCTION_ARGS)
PG_RETURN_INT32((int32) a - (int32) b);
}
+static Datum
+bool_decrement(Relation rel, Datum existing, bool *underflow)
+{
+ bool bexisting = DatumGetBool(existing);
+
+ if (bexisting == false)
+ {
+ /* return value is undefined */
+ *underflow = true;
+ return (Datum) 0;
+ }
+
+ *underflow = false;
+ return BoolGetDatum(bexisting - 1);
+}
+
+static Datum
+bool_increment(Relation rel, Datum existing, bool *overflow)
+{
+ bool bexisting = DatumGetBool(existing);
+
+ if (bexisting == true)
+ {
+ /* return value is undefined */
+ *overflow = true;
+ return (Datum) 0;
+ }
+
+ *overflow = false;
+ return BoolGetDatum(bexisting + 1);
+}
+
+Datum
+btboolskipsupport(PG_FUNCTION_ARGS)
+{
+ SkipSupport sksup = (SkipSupport) PG_GETARG_POINTER(0);
+
+ sksup->decrement = bool_decrement;
+ sksup->increment = bool_increment;
+ sksup->low_elem = BoolGetDatum(false);
+ sksup->high_elem = BoolGetDatum(true);
+
+ PG_RETURN_VOID();
+}
+
Datum
btint2cmp(PG_FUNCTION_ARGS)
{
@@ -105,6 +151,51 @@ btint2sortsupport(PG_FUNCTION_ARGS)
PG_RETURN_VOID();
}
+static Datum
+int2_decrement(Relation rel, Datum existing, bool *underflow)
+{
+ int16 iexisting = DatumGetInt16(existing);
+
+ if (iexisting == PG_INT16_MIN)
+ {
+ /* return value is undefined */
+ *underflow = true;
+ return (Datum) 0;
+ }
+
+ *underflow = false;
+ return Int16GetDatum(iexisting - 1);
+}
+
+static Datum
+int2_increment(Relation rel, Datum existing, bool *overflow)
+{
+ int16 iexisting = DatumGetInt16(existing);
+
+ if (iexisting == PG_INT16_MAX)
+ {
+ /* return value is undefined */
+ *overflow = true;
+ return (Datum) 0;
+ }
+
+ *overflow = false;
+ return Int16GetDatum(iexisting + 1);
+}
+
+Datum
+btint2skipsupport(PG_FUNCTION_ARGS)
+{
+ SkipSupport sksup = (SkipSupport) PG_GETARG_POINTER(0);
+
+ sksup->decrement = int2_decrement;
+ sksup->increment = int2_increment;
+ sksup->low_elem = Int16GetDatum(PG_INT16_MIN);
+ sksup->high_elem = Int16GetDatum(PG_INT16_MAX);
+
+ PG_RETURN_VOID();
+}
+
Datum
btint4cmp(PG_FUNCTION_ARGS)
{
@@ -128,6 +219,51 @@ btint4sortsupport(PG_FUNCTION_ARGS)
PG_RETURN_VOID();
}
+static Datum
+int4_decrement(Relation rel, Datum existing, bool *underflow)
+{
+ int32 iexisting = DatumGetInt32(existing);
+
+ if (iexisting == PG_INT32_MIN)
+ {
+ /* return value is undefined */
+ *underflow = true;
+ return (Datum) 0;
+ }
+
+ *underflow = false;
+ return Int32GetDatum(iexisting - 1);
+}
+
+static Datum
+int4_increment(Relation rel, Datum existing, bool *overflow)
+{
+ int32 iexisting = DatumGetInt32(existing);
+
+ if (iexisting == PG_INT32_MAX)
+ {
+ /* return value is undefined */
+ *overflow = true;
+ return (Datum) 0;
+ }
+
+ *overflow = false;
+ return Int32GetDatum(iexisting + 1);
+}
+
+Datum
+btint4skipsupport(PG_FUNCTION_ARGS)
+{
+ SkipSupport sksup = (SkipSupport) PG_GETARG_POINTER(0);
+
+ sksup->decrement = int4_decrement;
+ sksup->increment = int4_increment;
+ sksup->low_elem = Int32GetDatum(PG_INT32_MIN);
+ sksup->high_elem = Int32GetDatum(PG_INT32_MAX);
+
+ PG_RETURN_VOID();
+}
+
Datum
btint8cmp(PG_FUNCTION_ARGS)
{
@@ -171,6 +307,51 @@ btint8sortsupport(PG_FUNCTION_ARGS)
PG_RETURN_VOID();
}
+static Datum
+int8_decrement(Relation rel, Datum existing, bool *underflow)
+{
+ int64 iexisting = DatumGetInt64(existing);
+
+ if (iexisting == PG_INT64_MIN)
+ {
+ /* return value is undefined */
+ *underflow = true;
+ return (Datum) 0;
+ }
+
+ *underflow = false;
+ return Int64GetDatum(iexisting - 1);
+}
+
+static Datum
+int8_increment(Relation rel, Datum existing, bool *overflow)
+{
+ int64 iexisting = DatumGetInt64(existing);
+
+ if (iexisting == PG_INT64_MAX)
+ {
+ /* return value is undefined */
+ *overflow = true;
+ return (Datum) 0;
+ }
+
+ *overflow = false;
+ return Int64GetDatum(iexisting + 1);
+}
+
+Datum
+btint8skipsupport(PG_FUNCTION_ARGS)
+{
+ SkipSupport sksup = (SkipSupport) PG_GETARG_POINTER(0);
+
+ sksup->decrement = int8_decrement;
+ sksup->increment = int8_increment;
+ sksup->low_elem = Int64GetDatum(PG_INT64_MIN);
+ sksup->high_elem = Int64GetDatum(PG_INT64_MAX);
+
+ PG_RETURN_VOID();
+}
+
Datum
btint48cmp(PG_FUNCTION_ARGS)
{
@@ -292,6 +473,51 @@ btoidsortsupport(PG_FUNCTION_ARGS)
PG_RETURN_VOID();
}
+static Datum
+oid_decrement(Relation rel, Datum existing, bool *underflow)
+{
+ Oid oexisting = DatumGetObjectId(existing);
+
+ if (oexisting == InvalidOid)
+ {
+ /* return value is undefined */
+ *underflow = true;
+ return (Datum) 0;
+ }
+
+ *underflow = false;
+ return ObjectIdGetDatum(oexisting - 1);
+}
+
+static Datum
+oid_increment(Relation rel, Datum existing, bool *overflow)
+{
+ Oid oexisting = DatumGetObjectId(existing);
+
+ if (oexisting == OID_MAX)
+ {
+ /* return value is undefined */
+ *overflow = true;
+ return (Datum) 0;
+ }
+
+ *overflow = false;
+ return ObjectIdGetDatum(oexisting + 1);
+}
+
+Datum
+btoidskipsupport(PG_FUNCTION_ARGS)
+{
+ SkipSupport sksup = (SkipSupport) PG_GETARG_POINTER(0);
+
+ sksup->decrement = oid_decrement;
+ sksup->increment = oid_increment;
+ sksup->low_elem = ObjectIdGetDatum(InvalidOid);
+ sksup->high_elem = ObjectIdGetDatum(OID_MAX);
+
+ PG_RETURN_VOID();
+}
+
Datum
btoidvectorcmp(PG_FUNCTION_ARGS)
{
@@ -325,3 +551,50 @@ btcharcmp(PG_FUNCTION_ARGS)
/* Be careful to compare chars as unsigned */
PG_RETURN_INT32((int32) ((uint8) a) - (int32) ((uint8) b));
}
+
+static Datum
+char_decrement(Relation rel, Datum existing, bool *underflow)
+{
+ uint8 cexisting = UInt8GetDatum(existing);
+
+ if (cexisting == 0)
+ {
+ /* return value is undefined */
+ *underflow = true;
+ return (Datum) 0;
+ }
+
+ *underflow = false;
+ return CharGetDatum((uint8) cexisting - 1);
+}
+
+static Datum
+char_increment(Relation rel, Datum existing, bool *overflow)
+{
+ uint8 cexisting = UInt8GetDatum(existing);
+
+ if (cexisting == UCHAR_MAX)
+ {
+ /* return value is undefined */
+ *overflow = true;
+ return (Datum) 0;
+ }
+
+ *overflow = false;
+ return CharGetDatum((uint8) cexisting + 1);
+}
+
+Datum
+btcharskipsupport(PG_FUNCTION_ARGS)
+{
+ SkipSupport sksup = (SkipSupport) PG_GETARG_POINTER(0);
+
+ sksup->decrement = char_decrement;
+ sksup->increment = char_increment;
+
+ /* btcharcmp compares chars as unsigned */
+ sksup->low_elem = UInt8GetDatum(0);
+ sksup->high_elem = UInt8GetDatum(UCHAR_MAX);
+
+ PG_RETURN_VOID();
+}
diff --git a/src/backend/access/nbtree/nbtpreprocesskeys.c b/src/backend/access/nbtree/nbtpreprocesskeys.c
index 38a87af1cc8..791aa4ece40 100644
--- a/src/backend/access/nbtree/nbtpreprocesskeys.c
+++ b/src/backend/access/nbtree/nbtpreprocesskeys.c
@@ -45,8 +45,15 @@ static bool _bt_compare_array_scankey_args(IndexScanDesc scan,
ScanKey arraysk, ScanKey skey,
FmgrInfo *orderproc, BTArrayKeyInfo *array,
bool *qual_ok);
+static bool _bt_saoparray_shrink(IndexScanDesc scan, ScanKey arraysk,
+ ScanKey skey, FmgrInfo *orderproc,
+ BTArrayKeyInfo *array, bool *qual_ok);
+static bool _bt_skiparray_shrink(IndexScanDesc scan, ScanKey skey,
+ BTArrayKeyInfo *array, bool *qual_ok);
static ScanKey _bt_preprocess_array_keys(IndexScanDesc scan, int *new_numberOfKeys);
static void _bt_preprocess_array_keys_final(IndexScanDesc scan, int *keyDataMap);
+static int _bt_num_array_keys(IndexScanDesc scan, Oid *skip_eq_ops_out,
+ int *numSkipArrayKeys_out);
static Datum _bt_find_extreme_element(IndexScanDesc scan, ScanKey skey,
Oid elemtype, StrategyNumber strat,
Datum *elems, int nelems);
@@ -89,6 +96,8 @@ static int _bt_compare_array_elements(const void *a, const void *b, void *arg);
* within each attribute may be done as a byproduct of the processing here.
* That process must leave array scan keys (within an attribute) in the same
* order as corresponding entries from the scan's BTArrayKeyInfo array info.
+ * We might also construct skip array scan keys that weren't present in the
+ * original input keys; these are also output in standard attribute order.
*
* The output keys are marked with flags SK_BT_REQFWD and/or SK_BT_REQBKWD
* if they must be satisfied in order to continue the scan forward or backward
@@ -101,10 +110,16 @@ static int _bt_compare_array_elements(const void *a, const void *b, void *arg);
* attributes with "=" keys are marked both SK_BT_REQFWD and SK_BT_REQBKWD.
* For the first attribute without an "=" key, any "<" and "<=" keys are
* marked SK_BT_REQFWD while any ">" and ">=" keys are marked SK_BT_REQBKWD.
- * This can be seen to be correct by considering the above example. Note
- * in particular that if there are no keys for a given attribute, the keys for
- * subsequent attributes can never be required; for instance "WHERE y = 4"
- * requires a full-index scan.
+ * This can be seen to be correct by considering the above example.
+ *
+ * If we never generated skip array scan keys, it would be possible for "gaps"
+ * to appear that make it unsafe to mark any subsequent input scan keys
+ * (copied from scan->keyData[]) as required to continue the scan. Prior to
+ * Postgres 18, a qual like "WHERE y = 4" always resulted in a full scan.
+ * This qual now becomes "WHERE x = ANY('{every possible x value}') and y = 4"
+ * on output. In other words, preprocessing now adds a skip array on "x".
+ * This has the potential to be much more efficient than a full index scan
+ * (though it behaves like a full scan when there's many distinct "x" values).
*
* If possible, redundant keys are eliminated: we keep only the tightest
* >/>= bound and the tightest </<= bound, and if there's an = key then
@@ -137,11 +152,20 @@ static int _bt_compare_array_elements(const void *a, const void *b, void *arg);
* Again, missing cross-type operators might cause us to fail to prove the
* quals contradictory when they really are, but the scan will work correctly.
*
- * Row comparison keys are currently also treated without any smarts:
- * we just transfer them into the preprocessed array without any
+ * Skip array = keys will even be generated in the presence of "contradictory"
+ * inequality quals when it'll enable marking later input quals as required.
+ * We'll merge any such inequalities into the generated skip array by setting
+ * its array.low_compare or array.high_compare key field. The resulting skip
+ * array will generate its array elements from a range that's constrained by
+ * any merged input inequalities (which won't get output in so->keyData[]).
+ *
+ * Row comparison keys currently have a couple of notable limitations.
+ * Right now we just transfer them into the preprocessed array without any
* editorialization. We can treat them the same as an ordinary inequality
* comparison on the row's first index column, for the purposes of the logic
- * about required keys.
+ * about required keys. Also, we are unable to merge a row comparison key
+ * into a skip array (only ordinary inequalities are merged). A key that
+ * comes after a Row comparison key is therefore never marked as required.
*
* Note: the reason we have to copy the preprocessed scan keys into private
* storage is that we are modifying the array based on comparisons of the
@@ -200,6 +224,14 @@ _bt_preprocess_keys(IndexScanDesc scan)
/* Also maintain keyDataMap for remapping so->orderProcs[] later */
keyDataMap = MemoryContextAlloc(so->arrayContext,
numberOfKeys * sizeof(int));
+
+ /*
+ * Also enlarge output array when it might otherwise not have room for
+ * a skip array's scan key
+ */
+ if (numberOfKeys > scan->numberOfKeys)
+ so->keyData = repalloc(so->keyData,
+ numberOfKeys * sizeof(ScanKeyData));
}
else
inkeys = scan->keyData;
@@ -229,6 +261,7 @@ _bt_preprocess_keys(IndexScanDesc scan)
Assert(so->keyData[0].sk_flags & SK_SEARCHARRAY);
Assert(so->keyData[0].sk_strategy != BTEqualStrategyNumber ||
(so->arrayKeys[0].scan_key == 0 &&
+ !(so->keyData[0].sk_flags & SK_BT_SKIP) &&
OidIsValid(so->orderProcs[0].fn_oid)));
}
@@ -288,7 +321,8 @@ _bt_preprocess_keys(IndexScanDesc scan)
* redundant. Note that this is no less true if the = key is
* SEARCHARRAY; the only real difference is that the inequality
* key _becomes_ redundant by making _bt_compare_scankey_args
- * eliminate the subset of elements that won't need to be matched.
+ * eliminate the subset of elements that won't need to be matched
+ * (with SAOP arrays and skip arrays alike).
*
* If we have a case like "key = 1 AND key > 2", we set qual_ok to
* false and abandon further processing. We'll do the same thing
@@ -345,7 +379,6 @@ _bt_preprocess_keys(IndexScanDesc scan)
return;
}
/* else discard the redundant non-equality key */
- Assert(!array || array->num_elems > 0);
xform[j].inkey = NULL;
xform[j].inkeyi = -1;
}
@@ -393,6 +426,11 @@ _bt_preprocess_keys(IndexScanDesc scan)
* Emit the cleaned-up keys into the so->keyData[] array, and then
* mark them if they are required. They are required (possibly
* only in one direction) if all attrs before this one had "=".
+ *
+ * In practice we'll rarely output non-required scan keys here;
+ * typically, _bt_preprocess_array_keys has already added "=" keys
+ * sufficient to form an unbroken series of "=" constraints on all
+ * attrs prior to the attr from the final scan->keyData[] key.
*/
for (j = BTMaxStrategyNumber; --j >= 0;)
{
@@ -481,6 +519,7 @@ _bt_preprocess_keys(IndexScanDesc scan)
Assert(array->scan_key == i);
Assert(OidIsValid(orderproc->fn_oid));
+ Assert(!(inkey->sk_flags & SK_BT_SKIP));
}
else if (xform[j].inkey->sk_flags & SK_SEARCHARRAY)
{
@@ -489,6 +528,7 @@ _bt_preprocess_keys(IndexScanDesc scan)
Assert(array->scan_key == xform[j].inkeyi);
Assert(OidIsValid(orderproc->fn_oid));
+ Assert(!(xform[j].inkey->sk_flags & SK_BT_SKIP));
}
/*
@@ -508,8 +548,6 @@ _bt_preprocess_keys(IndexScanDesc scan)
/* Have all we need to determine redundancy */
if (test_result)
{
- Assert(!array || array->num_elems > 0);
-
/*
* New key is more restrictive, and so replaces old key...
*/
@@ -803,6 +841,9 @@ _bt_compare_scankey_args(IndexScanDesc scan, ScanKey op,
cmp_op;
StrategyNumber strat;
+ Assert(!((leftarg->sk_flags | rightarg->sk_flags) &
+ (SK_ROW_HEADER | SK_ROW_MEMBER)));
+
/*
* First, deal with cases where one or both args are NULL. This should
* only happen when the scankeys represent IS NULL/NOT NULL conditions.
@@ -812,6 +853,22 @@ _bt_compare_scankey_args(IndexScanDesc scan, ScanKey op,
bool leftnull,
rightnull;
+ /* Handle skip array comparison with IS NOT NULL scan key */
+ if ((leftarg->sk_flags | rightarg->sk_flags) & SK_BT_SKIP)
+ {
+ /* Shouldn't generate skip array in presence of IS NULL key */
+ Assert(!((leftarg->sk_flags | rightarg->sk_flags) & SK_SEARCHNULL));
+ Assert((leftarg->sk_flags | rightarg->sk_flags) & SK_SEARCHNOTNULL);
+
+ /* Skip array will have no NULL element/IS NULL scan key */
+ Assert(array->num_elems == -1);
+ array->null_elem = false;
+
+ /* IS NOT NULL key (could be leftarg or rightarg) now redundant */
+ *result = true;
+ return true;
+ }
+
if (leftarg->sk_flags & SK_ISNULL)
{
Assert(leftarg->sk_flags & (SK_SEARCHNULL | SK_SEARCHNOTNULL));
@@ -885,6 +942,7 @@ _bt_compare_scankey_args(IndexScanDesc scan, ScanKey op,
{
/* Can't make the comparison */
*result = false; /* suppress compiler warnings */
+ Assert(!((leftarg->sk_flags | rightarg->sk_flags) & SK_BT_SKIP));
return false;
}
@@ -978,24 +1036,56 @@ _bt_compare_scankey_args(IndexScanDesc scan, ScanKey op,
* Compare an array scan key to a scalar scan key, eliminating contradictory
* array elements such that the scalar scan key becomes redundant.
*
+ * If the opfamily is incomplete we may not be able to determine which
+ * elements are contradictory. When we return true we'll have validly set
+ * *qual_ok, guaranteeing that at least the scalar scan key can be considered
+ * redundant. We return false if the comparison could not be made (caller
+ * must keep both scan keys when this happens).
+ *
+ * Note: it's up to caller to deal with IS [NOT] NULL scan keys, as well as
+ * row comparison scan keys. We only deal with scalar scan keys.
+ */
+static bool
+_bt_compare_array_scankey_args(IndexScanDesc scan, ScanKey arraysk, ScanKey skey,
+ FmgrInfo *orderproc, BTArrayKeyInfo *array,
+ bool *qual_ok)
+{
+ Assert(arraysk->sk_attno == skey->sk_attno);
+ Assert(!(arraysk->sk_flags & (SK_ISNULL | SK_ROW_HEADER | SK_ROW_MEMBER)));
+ Assert((arraysk->sk_flags & SK_SEARCHARRAY) &&
+ arraysk->sk_strategy == BTEqualStrategyNumber);
+ /* don't expect to have to deal with NULLs/row comparison scan keys */
+ Assert(!(skey->sk_flags & (SK_ISNULL | SK_ROW_HEADER | SK_ROW_MEMBER)));
+ Assert(!(skey->sk_flags & SK_SEARCHARRAY) ||
+ skey->sk_strategy != BTEqualStrategyNumber);
+
+ /*
+ * Just call the appropriate helper function based on whether it's a SAOP
+ * array or a skip array. Both helpers will set *qual_ok in passing.
+ */
+ if (array->num_elems != -1)
+ return _bt_saoparray_shrink(scan, arraysk, skey, orderproc, array,
+ qual_ok);
+ else
+ return _bt_skiparray_shrink(scan, skey, array, qual_ok);
+}
+
+/*
+ * Preprocessing of SAOP array scan key, used to determine which array
+ * elements are eliminated as contradictory by a non-array scalar key.
+ *
+ * _bt_compare_array_scankey_args helper function.
+ *
* Array elements can be eliminated as contradictory when excluded by some
* other operator on the same attribute. For example, with an index scan qual
* "WHERE a IN (1, 2, 3) AND a < 2", all array elements except the value "1"
* are eliminated, and the < scan key is eliminated as redundant. Cases where
* every array element is eliminated by a redundant scalar scan key have an
* unsatisfiable qual, which we handle by setting *qual_ok=false for caller.
- *
- * If the opfamily doesn't supply a complete set of cross-type ORDER procs we
- * may not be able to determine which elements are contradictory. If we have
- * the required ORDER proc then we return true (and validly set *qual_ok),
- * guaranteeing that at least the scalar scan key can be considered redundant.
- * We return false if the comparison could not be made (caller must keep both
- * scan keys when this happens).
*/
static bool
-_bt_compare_array_scankey_args(IndexScanDesc scan, ScanKey arraysk, ScanKey skey,
- FmgrInfo *orderproc, BTArrayKeyInfo *array,
- bool *qual_ok)
+_bt_saoparray_shrink(IndexScanDesc scan, ScanKey arraysk, ScanKey skey,
+ FmgrInfo *orderproc, BTArrayKeyInfo *array, bool *qual_ok)
{
Relation rel = scan->indexRelation;
Oid opcintype = rel->rd_opcintype[arraysk->sk_attno - 1];
@@ -1006,14 +1096,8 @@ _bt_compare_array_scankey_args(IndexScanDesc scan, ScanKey arraysk, ScanKey skey
FmgrInfo crosstypeproc;
FmgrInfo *orderprocp = orderproc;
- Assert(arraysk->sk_attno == skey->sk_attno);
Assert(array->num_elems > 0);
- Assert(!(arraysk->sk_flags & (SK_ISNULL | SK_ROW_HEADER | SK_ROW_MEMBER)));
- Assert((arraysk->sk_flags & SK_SEARCHARRAY) &&
- arraysk->sk_strategy == BTEqualStrategyNumber);
- Assert(!(skey->sk_flags & (SK_ISNULL | SK_ROW_HEADER | SK_ROW_MEMBER)));
- Assert(!(skey->sk_flags & SK_SEARCHARRAY) ||
- skey->sk_strategy != BTEqualStrategyNumber);
+ Assert(!(arraysk->sk_flags & SK_BT_SKIP));
/*
* _bt_binsrch_array_skey searches an array for the entry best matching a
@@ -1113,6 +1197,106 @@ _bt_compare_array_scankey_args(IndexScanDesc scan, ScanKey arraysk, ScanKey skey
}
/*
+ * Preprocessing of skip array scan key, used to determine redundancy against
+ * a non-array scalar scan key (must be an inequality).
+ *
+ * _bt_compare_array_scankey_args helper function.
+ *
+ * Skip arrays work by procedurally generating their elements as needed, so we
+ * just store the inequality as the skip array's low_compare or high_compare
+ * (except when there's already a more restrictive low_compare/high_compare).
+ * The array's final elements are the range of values that still satisfy the
+ * array's final low_compare and high_compare.
+ */
+static bool
+_bt_skiparray_shrink(IndexScanDesc scan, ScanKey skey, BTArrayKeyInfo *array,
+ bool *qual_ok)
+{
+ bool test_result;
+
+ Assert(array->num_elems == -1);
+
+ /*
+ * Array's index attribute will be constrained by a strict operator/key.
+ * Array must not "contain a NULL element" (i.e. the scan must not apply
+ * "IS NULL" qual when it reaches the end of the index that stores NULLs).
+ */
+ array->null_elem = false;
+ *qual_ok = true;
+
+ /*
+ * Consider if we should treat caller's scalar scan key as the skip
+ * array's high_compare or low_compare.
+ *
+ * In general the current array element must either be a copy of a value
+ * taken from an index tuple, or a derivative value generated by opclass's
+ * skip support function. That way the scan can always safely assume that
+ * it's okay to use the only-input-opclass-type proc from so->orderProcs[]
+ * (they can be cross-type with SAOP arrays, but never with skip arrays).
+ *
+ * This approach is enabled by MINVAL/MAXVAL sentinel key markings, which
+ * can be thought of as representing either the lowest or highest matching
+ * array element (excluding the NULL element, where applicable, though as
+ * just discussed it isn't applicable to this range skip array anyway).
+ * Array keys marked MINVAL/MAXVAL never have a valid datum in their
+ * sk_argument field. The scan directly applies the array's low_compare
+ * key when it encounters MINVAL in the array key proper (just as it
+ * applies high_compare when it sees MAXVAL set in the array key proper).
+ * The scan must never use the array's so->orderProcs[] proc against
+ * low_compare's/high_compare's sk_argument, either (so->orderProcs[] is
+ * only intended to be used with rhs datums from the array proper/index).
+ */
+ switch (skey->sk_strategy)
+ {
+ case BTLessStrategyNumber:
+ case BTLessEqualStrategyNumber:
+ if (array->high_compare)
+ {
+ /* replace existing high_compare with caller's key? */
+ if (!_bt_compare_scankey_args(scan, array->high_compare, skey,
+ array->high_compare, NULL, NULL,
+ &test_result))
+ return false; /* can't determine more restrictive key */
+
+ if (!test_result)
+ return true; /* no, just discard caller's key */
+
+ /* yes, replace existing high_compare with caller's key */
+ }
+
+ /* caller's key becomes skip array's high_compare */
+ array->high_compare = skey;
+ break;
+ case BTGreaterEqualStrategyNumber:
+ case BTGreaterStrategyNumber:
+ if (array->low_compare)
+ {
+ /* replace existing low_compare with caller's key? */
+ if (!_bt_compare_scankey_args(scan, array->low_compare, skey,
+ array->low_compare, NULL, NULL,
+ &test_result))
+ return false; /* can't determine more restrictive key */
+
+ if (!test_result)
+ return true; /* no, just discard caller's key */
+
+ /* yes, replace existing low_compare with caller's key */
+ }
+
+ /* caller's key becomes skip array's low_compare */
+ array->low_compare = skey;
+ break;
+ case BTEqualStrategyNumber:
+ default:
+ elog(ERROR, "unrecognized StrategyNumber: %d",
+ (int) skey->sk_strategy);
+ break;
+ }
+
+ return true;
+}
+
+/*
* _bt_preprocess_array_keys() -- Preprocess SK_SEARCHARRAY scan keys
*
* If there are any SK_SEARCHARRAY scan keys, deconstruct the array(s) and
@@ -1137,6 +1321,12 @@ _bt_compare_array_scankey_args(IndexScanDesc scan, ScanKey arraysk, ScanKey skey
* one equality strategy array scan key per index attribute. We'll always be
* able to set things up that way when complete opfamilies are used.
*
+ * We're also responsible for generating skip arrays (and their associated
+ * scan keys) here. This enables skip scan. We do this for index attributes
+ * that initially lacked an equality condition within scan->keyData[], iff
+ * doing so allows a later scan key (that was passed to us in scan->keyData[])
+ * to be marked required by our _bt_preprocess_keys caller.
+ *
* We set the scan key references from the scan's BTArrayKeyInfo info array to
* offsets into the temp modified input array returned to caller. Scans that
* have array keys should call _bt_preprocess_array_keys_final when standard
@@ -1144,50 +1334,46 @@ _bt_compare_array_scankey_args(IndexScanDesc scan, ScanKey arraysk, ScanKey skey
* references into references to the scan's so->keyData[] output scan keys.
*
* Note: the reason we need to return a temp scan key array, rather than just
- * scribbling on scan->keyData, is that callers are permitted to call btrescan
- * without supplying a new set of scankey data.
+ * modifying scan->keyData[], is that callers are permitted to call btrescan
+ * without supplying a new set of scankey data. Certain other preprocessing
+ * routines (e.g., _bt_fix_scankey_strategy) _can_ modify scan->keyData[], but
+ * we can't make that work here because our modifications are non-idempotent.
*/
static ScanKey
_bt_preprocess_array_keys(IndexScanDesc scan, int *new_numberOfKeys)
{
BTScanOpaque so = (BTScanOpaque) scan->opaque;
Relation rel = scan->indexRelation;
- int numberOfKeys = scan->numberOfKeys;
int16 *indoption = rel->rd_indoption;
+ Oid skip_eq_ops[INDEX_MAX_KEYS];
int numArrayKeys,
- output_ikey = 0;
+ numSkipArrayKeys,
+ numArrayKeyData;
+ AttrNumber attno_skip = 1;
int origarrayatt = InvalidAttrNumber,
origarraykey = -1;
Oid origelemtype = InvalidOid;
- ScanKey cur;
MemoryContext oldContext;
ScanKey arrayKeyData; /* modified copy of scan->keyData */
- Assert(numberOfKeys);
-
- /* Quick check to see if there are any array keys */
- numArrayKeys = 0;
- for (int i = 0; i < numberOfKeys; i++)
- {
- cur = &scan->keyData[i];
- if (cur->sk_flags & SK_SEARCHARRAY)
- {
- numArrayKeys++;
- Assert(!(cur->sk_flags & (SK_ROW_HEADER | SK_SEARCHNULL | SK_SEARCHNOTNULL)));
- /* If any arrays are null as a whole, we can quit right now. */
- if (cur->sk_flags & SK_ISNULL)
- {
- so->qual_ok = false;
- return NULL;
- }
- }
- }
+ /*
+ * Check the number of input array keys within scan->keyData[] input keys
+ * (also checks if we should add extra skip arrays based on input keys)
+ */
+ numArrayKeys = _bt_num_array_keys(scan, skip_eq_ops, &numSkipArrayKeys);
/* Quit if nothing to do. */
if (numArrayKeys == 0)
return NULL;
/*
+ * Estimated final size of arrayKeyData[] array we'll return to our caller
+ * is the size of the original scan->keyData[] input array, plus space for
+ * any additional skip array scan keys we'll need to generate below
+ */
+ numArrayKeyData = scan->numberOfKeys + numSkipArrayKeys;
+
+ /*
* Make a scan-lifespan context to hold array-associated data, or reset it
* if we already have one from a previous rescan cycle.
*/
@@ -1201,18 +1387,20 @@ _bt_preprocess_array_keys(IndexScanDesc scan, int *new_numberOfKeys)
oldContext = MemoryContextSwitchTo(so->arrayContext);
/* Create output scan keys in the workspace context */
- arrayKeyData = (ScanKey) palloc(numberOfKeys * sizeof(ScanKeyData));
+ arrayKeyData = (ScanKey) palloc(numArrayKeyData * sizeof(ScanKeyData));
/* Allocate space for per-array data in the workspace context */
so->arrayKeys = (BTArrayKeyInfo *) palloc(numArrayKeys * sizeof(BTArrayKeyInfo));
/* Allocate space for ORDER procs used to help _bt_checkkeys */
- so->orderProcs = (FmgrInfo *) palloc(numberOfKeys * sizeof(FmgrInfo));
+ so->orderProcs = (FmgrInfo *) palloc(numArrayKeyData * sizeof(FmgrInfo));
- /* Now process each array key */
numArrayKeys = 0;
- for (int input_ikey = 0; input_ikey < numberOfKeys; input_ikey++)
+ numArrayKeyData = 0;
+ for (int input_ikey = 0; input_ikey < scan->numberOfKeys; input_ikey++)
{
+ ScanKey inkey = scan->keyData + input_ikey,
+ cur;
FmgrInfo sortproc;
FmgrInfo *sortprocp = &sortproc;
Oid elemtype;
@@ -1225,22 +1413,114 @@ _bt_preprocess_array_keys(IndexScanDesc scan, int *new_numberOfKeys)
Datum *elem_values;
bool *elem_nulls;
int num_nonnulls;
- int j;
+
+ /* set up next output scan key */
+ cur = &arrayKeyData[numArrayKeyData];
+
+ /* Backfill skip arrays for attrs < or <= input key's attr? */
+ while (numSkipArrayKeys && attno_skip <= inkey->sk_attno)
+ {
+ Oid opfamily = rel->rd_opfamily[attno_skip - 1];
+ Oid opcintype = rel->rd_opcintype[attno_skip - 1];
+ Oid collation = rel->rd_indcollation[attno_skip - 1];
+ Oid eq_op = skip_eq_ops[attno_skip - 1];
+ CompactAttribute *attr;
+ RegProcedure cmp_proc;
+
+ if (!OidIsValid(eq_op))
+ {
+ /*
+ * Attribute already has an = input key, so don't output a
+ * skip array for attno_skip. Just copy attribute's = input
+ * key into arrayKeyData[] once outside this inner loop.
+ *
+ * Note: When we get here there must be a later attribute that
+ * lacks an equality input key, and still needs a skip array
+ * (if there wasn't then numSkipArrayKeys would be 0 by now).
+ */
+ Assert(attno_skip == inkey->sk_attno);
+ /* inkey can't be last input key to be marked required: */
+ Assert(input_ikey < scan->numberOfKeys - 1);
+#if 0
+ /* Could be a redundant input scan key, so can't do this: */
+ Assert(inkey->sk_strategy == BTEqualStrategyNumber ||
+ (inkey->sk_flags & SK_SEARCHNULL));
+#endif
+
+ attno_skip++;
+ break;
+ }
+
+ cmp_proc = get_opcode(eq_op);
+ if (!RegProcedureIsValid(cmp_proc))
+ elog(ERROR, "missing oprcode for skipping equals operator %u", eq_op);
+
+ ScanKeyEntryInitialize(cur,
+ SK_SEARCHARRAY | SK_BT_SKIP, /* flags */
+ attno_skip, /* skipped att number */
+ BTEqualStrategyNumber, /* equality strategy */
+ InvalidOid, /* opclass input subtype */
+ collation, /* index column's collation */
+ cmp_proc, /* equality operator's proc */
+ (Datum) 0); /* constant */
+
+ /* Initialize generic BTArrayKeyInfo fields */
+ so->arrayKeys[numArrayKeys].scan_key = numArrayKeyData;
+ so->arrayKeys[numArrayKeys].num_elems = -1;
+
+ /* Initialize skip array specific BTArrayKeyInfo fields */
+ attr = TupleDescCompactAttr(RelationGetDescr(rel), attno_skip - 1);
+ reverse = (indoption[attno_skip - 1] & INDOPTION_DESC) != 0;
+ so->arrayKeys[numArrayKeys].attlen = attr->attlen;
+ so->arrayKeys[numArrayKeys].attbyval = attr->attbyval;
+ so->arrayKeys[numArrayKeys].null_elem = true; /* for now */
+ so->arrayKeys[numArrayKeys].sksup =
+ PrepareSkipSupportFromOpclass(opfamily, opcintype, reverse);
+ so->arrayKeys[numArrayKeys].low_compare = NULL; /* for now */
+ so->arrayKeys[numArrayKeys].high_compare = NULL; /* for now */
+
+ /*
+ * We'll need a 3-way ORDER proc. Set that up now.
+ */
+ _bt_setup_array_cmp(scan, cur, opcintype,
+ &so->orderProcs[numArrayKeyData], NULL);
+
+ numArrayKeys++;
+ numArrayKeyData++; /* keep this scan key/array */
+
+ /* set up next output scan key */
+ cur = &arrayKeyData[numArrayKeyData];
+
+ /* remember having output this skip array and scan key */
+ numSkipArrayKeys--;
+ attno_skip++;
+ }
/*
* Provisionally copy scan key into arrayKeyData[] array we'll return
* to _bt_preprocess_keys caller
*/
- cur = &arrayKeyData[output_ikey];
- *cur = scan->keyData[input_ikey];
+ *cur = *inkey;
if (!(cur->sk_flags & SK_SEARCHARRAY))
{
- output_ikey++; /* keep this non-array scan key */
+ numArrayKeyData++; /* keep this non-array scan key */
continue;
}
/*
+ * Process SAOP array scan key
+ */
+ Assert(!(cur->sk_flags & (SK_ROW_HEADER | SK_SEARCHNULL | SK_SEARCHNOTNULL)));
+
+ /* If array is null as a whole, the scan qual is unsatisfiable */
+ if (cur->sk_flags & SK_ISNULL)
+ {
+ so->qual_ok = false;
+ break;
+ }
+
+ /*
* Deconstruct the array into elements
*/
arrayval = DatumGetArrayTypeP(cur->sk_argument);
@@ -1257,7 +1537,7 @@ _bt_preprocess_array_keys(IndexScanDesc scan, int *new_numberOfKeys)
* all btree operators are strict.
*/
num_nonnulls = 0;
- for (j = 0; j < num_elems; j++)
+ for (int j = 0; j < num_elems; j++)
{
if (!elem_nulls[j])
elem_values[num_nonnulls++] = elem_values[j];
@@ -1295,7 +1575,7 @@ _bt_preprocess_array_keys(IndexScanDesc scan, int *new_numberOfKeys)
_bt_find_extreme_element(scan, cur, elemtype,
BTGreaterStrategyNumber,
elem_values, num_nonnulls);
- output_ikey++; /* keep this transformed scan key */
+ numArrayKeyData++; /* keep this transformed scan key */
continue;
case BTEqualStrategyNumber:
/* proceed with rest of loop */
@@ -1306,7 +1586,7 @@ _bt_preprocess_array_keys(IndexScanDesc scan, int *new_numberOfKeys)
_bt_find_extreme_element(scan, cur, elemtype,
BTLessStrategyNumber,
elem_values, num_nonnulls);
- output_ikey++; /* keep this transformed scan key */
+ numArrayKeyData++; /* keep this transformed scan key */
continue;
default:
elog(ERROR, "unrecognized StrategyNumber: %d",
@@ -1323,7 +1603,7 @@ _bt_preprocess_array_keys(IndexScanDesc scan, int *new_numberOfKeys)
* sortproc just points to the same proc used during binary searches.
*/
_bt_setup_array_cmp(scan, cur, elemtype,
- &so->orderProcs[output_ikey], &sortprocp);
+ &so->orderProcs[numArrayKeyData], &sortprocp);
/*
* Sort the non-null elements and eliminate any duplicates. We must
@@ -1392,23 +1672,24 @@ _bt_preprocess_array_keys(IndexScanDesc scan, int *new_numberOfKeys)
origelemtype = elemtype;
}
- /*
- * And set up the BTArrayKeyInfo data.
- *
- * Note: _bt_preprocess_array_keys_final will fix-up each array's
- * scan_key field later on, after so->keyData[] has been finalized.
- */
- so->arrayKeys[numArrayKeys].scan_key = output_ikey;
+ /* Initialize generic BTArrayKeyInfo fields */
+ so->arrayKeys[numArrayKeys].scan_key = numArrayKeyData;
so->arrayKeys[numArrayKeys].num_elems = num_elems;
+
+ /* Initialize SAOP array specific BTArrayKeyInfo fields */
so->arrayKeys[numArrayKeys].elem_values = elem_values;
+ so->arrayKeys[numArrayKeys].cur_elem = -1; /* i.e. invalid */
+
numArrayKeys++;
- output_ikey++; /* keep this scan key/array */
+ numArrayKeyData++; /* keep this scan key/array */
}
+ Assert(numSkipArrayKeys == 0);
+
/* Set final number of equality-type array keys */
so->numArrayKeys = numArrayKeys;
- /* Set number of scan keys remaining in arrayKeyData[] */
- *new_numberOfKeys = output_ikey;
+ /* Set number of scan keys in arrayKeyData[] */
+ *new_numberOfKeys = numArrayKeyData;
MemoryContextSwitchTo(oldContext);
@@ -1514,7 +1795,14 @@ _bt_preprocess_array_keys_final(IndexScanDesc scan, int *keyDataMap)
{
BTArrayKeyInfo *array = &so->arrayKeys[arrayidx];
- Assert(array->num_elems > 0);
+ /*
+ * All skip arrays must be marked required, and final column can
+ * never have a skip array
+ */
+ Assert(array->num_elems > 0 || array->num_elems == -1);
+ Assert(array->num_elems != -1 || outkey->sk_flags & SK_BT_REQFWD);
+ Assert(array->num_elems != -1 ||
+ outkey->sk_attno < IndexRelationGetNumberOfKeyAttributes(rel));
if (array->scan_key == input_ikey)
{
@@ -1576,6 +1864,199 @@ _bt_preprocess_array_keys_final(IndexScanDesc scan, int *keyDataMap)
}
/*
+ * _bt_num_array_keys() -- determine # of BTArrayKeyInfo entries
+ *
+ * _bt_preprocess_array_keys helper function. Returns the estimated size of
+ * the scan's BTArrayKeyInfo array, which is guaranteed to be large enough to
+ * fit every so->arrayKeys[] entry.
+ *
+ * Also sets *numSkipArrayKeys_out to the number of of skip arrays caller must
+ * add to the scan keys it'll output. Caller must add this many skip arrays:
+ * one array for each of the most significant attributes that lack a = input
+ * key (IS NULL keys count as = input keys here). The specific attributes
+ * that need skip arrays are indicated by initializing skip_eq_ops_out[] arg
+ * 0-based attribute offset to a valid = op strategy Oid. We'll only ever set
+ * skip_eq_ops_out[] entries to InvalidOid for attributes that already have an
+ * equality key in scan->keyData[] input keys -- and only when there's some
+ * later "attribute gap" for us to "fill-in" with a skip array.
+ *
+ * We're optimistic about skipping working out: we always add exactly the skip
+ * arrays needed to maximize the number of input scan keys that can ultimately
+ * be marked as required to continue the scan (but no more). Given a
+ * multi-column index on (a, b, c, d), we add skip arrays as follows:
+ *
+ * Input keys Output keys (after all preprocessing)
+ * ---------- -------------------------------------
+ * a = 1 a = 1 (no skip arrays)
+ * b = 42 skip a AND b = 42
+ * a = 1 AND b = 42 a = 1 AND b = 42 (no skip arrays)
+ * a >= 1 AND b = 42 range skip a AND b = 42
+ * a = 1 AND b > 42 a = 1 AND b > 42 (no skip arrays)
+ * a >= 1 AND a <= 3 AND b = 42 range skip a AND b = 42
+ * a = 1 AND c <= 27 a = 1 AND skip b AND c <= 27
+ * a = 1 AND d >= 1 a = 1 AND skip b AND skip c AND d >= 1
+ * a = 1 AND b >= 42 AND d > 1 a = 1 AND range skip b AND skip c AND d > 1
+ */
+static int
+_bt_num_array_keys(IndexScanDesc scan, Oid *skip_eq_ops_out,
+ int *numSkipArrayKeys_out)
+{
+ Relation rel = scan->indexRelation;
+ AttrNumber attno_skip = 1,
+ attno_inkey = 1;
+ bool attno_has_equal = false,
+ attno_has_rowcompare = false;
+ int numSAOPArrayKeys,
+ numSkipArrayKeys,
+ prev_numSkipArrayKeys;
+
+ Assert(scan->numberOfKeys);
+
+ /* Initial pass over input scan keys counts the number of SAOP arrays */
+ numSAOPArrayKeys = 0;
+ *numSkipArrayKeys_out = prev_numSkipArrayKeys = numSkipArrayKeys = 0;
+ for (int i = 0; i < scan->numberOfKeys; i++)
+ {
+ ScanKey inkey = scan->keyData + i;
+
+ if (inkey->sk_flags & SK_SEARCHARRAY)
+ numSAOPArrayKeys++;
+ }
+
+#ifdef DEBUG_DISABLE_SKIP_SCAN
+ /* don't attempt to add skip arrays */
+ return numSAOPArrayKeys;
+#endif
+
+ for (int i = 0;; i++)
+ {
+ ScanKey inkey = scan->keyData + i;
+
+ /*
+ * Backfill skip arrays for any wholly omitted attributes prior to
+ * attno_inkey
+ */
+ while (attno_skip < attno_inkey)
+ {
+ Oid opfamily = rel->rd_opfamily[attno_skip - 1];
+ Oid opcintype = rel->rd_opcintype[attno_skip - 1];
+
+ /* Look up input opclass's equality operator (might fail) */
+ skip_eq_ops_out[attno_skip - 1] =
+ get_opfamily_member(opfamily, opcintype, opcintype,
+ BTEqualStrategyNumber);
+ if (!OidIsValid(skip_eq_ops_out[attno_skip - 1]))
+ {
+ /*
+ * Cannot generate a skip array for this or later attributes
+ * (input opclass lacks an equality strategy operator)
+ */
+ *numSkipArrayKeys_out = prev_numSkipArrayKeys;
+ return numSAOPArrayKeys + prev_numSkipArrayKeys;
+ }
+
+ /* plan on adding a backfill skip array for this attribute */
+ numSkipArrayKeys++;
+ attno_skip++;
+ }
+
+ prev_numSkipArrayKeys = numSkipArrayKeys;
+
+ /*
+ * Stop once past the final input scan key. We deliberately never add
+ * a skip array for the last input scan key's attribute -- even when
+ * there are only inequality keys on that attribute.
+ */
+ if (i == scan->numberOfKeys)
+ break;
+
+ /*
+ * Later preprocessing steps cannot merge a RowCompare into a skip
+ * array, so stop adding skip arrays once we see one. (Note that we
+ * can backfill skip arrays before a RowCompare, which will allow keys
+ * up to and including the RowCompare to be marked required.)
+ *
+ * Skip arrays work by maintaining a current array element value,
+ * which anchors lower-order keys via an implied equality constraint.
+ * This is incompatible with the current nbtree row comparison design,
+ * which compares all columns together, as an indivisible group.
+ * Alternative designs that can be used alongside skip arrays are
+ * possible, but it's not clear that they're really worth pursuing.
+ *
+ * A RowCompare qual "(a, b, c) > (10, 'foo', 42)" is equivalent to
+ * "(a=10 AND b='foo' AND c>42) OR (a=10 AND b>'foo') OR (a>10)".
+ * Decomposing this RowCompare into these 3 disjuncts allows each
+ * disjunct to be executed as a separate "single value" index scan.
+ * That'll give all 3 scans the ability to add skip arrays in the
+ * usual way (when there are any scalar keys after the RowCompare).
+ * Under this scheme, a qual "(a, b, c) > (10, 'foo', 42) AND d = 99"
+ * performs 3 separate scans, each of which can mark keys up to and
+ * including its "d = 99" key as required to continue the scan.
+ */
+ if (attno_has_rowcompare)
+ break;
+
+ /*
+ * Now consider next attno_inkey (or keep going if this is an
+ * additional scan key against the same attribute)
+ */
+ if (attno_inkey < inkey->sk_attno)
+ {
+ /*
+ * Now add skip array for previous scan key's attribute, though
+ * only if the attribute has no equality strategy scan keys
+ */
+ if (attno_has_equal)
+ {
+ /* Attributes with an = key must have InvalidOid eq_op set */
+ skip_eq_ops_out[attno_skip - 1] = InvalidOid;
+ }
+ else
+ {
+ Oid opfamily = rel->rd_opfamily[attno_skip - 1];
+ Oid opcintype = rel->rd_opcintype[attno_skip - 1];
+
+ /* Look up input opclass's equality operator (might fail) */
+ skip_eq_ops_out[attno_skip - 1] =
+ get_opfamily_member(opfamily, opcintype, opcintype,
+ BTEqualStrategyNumber);
+
+ if (!OidIsValid(skip_eq_ops_out[attno_skip - 1]))
+ {
+ /*
+ * Input opclass lacks an equality strategy operator, so
+ * don't generate a skip array that definitely won't work
+ */
+ break;
+ }
+
+ /* plan on adding a backfill skip array for this attribute */
+ numSkipArrayKeys++;
+ }
+
+ /* Set things up for this new attribute */
+ attno_skip++;
+ attno_inkey = inkey->sk_attno;
+ attno_has_equal = false;
+ }
+
+ /*
+ * Track if this attribute's scan keys include any equality strategy
+ * scan keys (IS NULL keys count as equality keys here). Also track
+ * if it has any RowCompare keys.
+ */
+ if (inkey->sk_strategy == BTEqualStrategyNumber ||
+ (inkey->sk_flags & SK_SEARCHNULL))
+ attno_has_equal = true;
+ if (inkey->sk_flags & SK_ROW_HEADER)
+ attno_has_rowcompare = true;
+ }
+
+ *numSkipArrayKeys_out = numSkipArrayKeys;
+ return numSAOPArrayKeys + numSkipArrayKeys;
+}
+
+/*
* _bt_find_extreme_element() -- get least or greatest array element
*
* scan and skey identify the index column, whose opfamily determines the
diff --git a/src/backend/access/nbtree/nbtree.c b/src/backend/access/nbtree/nbtree.c
index a99667eb2bd..77781cb9002 100644
--- a/src/backend/access/nbtree/nbtree.c
+++ b/src/backend/access/nbtree/nbtree.c
@@ -31,6 +31,7 @@
#include "storage/ipc.h"
#include "storage/lmgr.h"
#include "storage/read_stream.h"
+#include "utils/datum.h"
#include "utils/fmgrprotos.h"
#include "utils/index_selfuncs.h"
#include "utils/memutils.h"
@@ -76,14 +77,26 @@ typedef struct BTParallelScanDescData
/*
* btps_arrElems is used when scans need to schedule another primitive
- * index scan. Holds BTArrayKeyInfo.cur_elem offsets for scan keys.
+ * index scan with one or more SAOP arrays. Holds BTArrayKeyInfo.cur_elem
+ * offsets for each = scan key associated with a ScalarArrayOp array.
*/
int btps_arrElems[FLEXIBLE_ARRAY_MEMBER];
+
+ /*
+ * Additional space (at the end of the struct) is used when scans need to
+ * schedule another primitive index scan with one or more skip arrays.
+ * Holds a flattened datum representation for each = scan key associated
+ * with a skip array.
+ */
} BTParallelScanDescData;
typedef struct BTParallelScanDescData *BTParallelScanDesc;
+static void _bt_parallel_serialize_arrays(Relation rel, BTParallelScanDesc btscan,
+ BTScanOpaque so);
+static void _bt_parallel_restore_arrays(Relation rel, BTParallelScanDesc btscan,
+ BTScanOpaque so);
static void btvacuumscan(IndexVacuumInfo *info, IndexBulkDeleteResult *stats,
IndexBulkDeleteCallback callback, void *callback_state,
BTCycleId cycleid);
@@ -541,10 +554,167 @@ btrestrpos(IndexScanDesc scan)
* btestimateparallelscan -- estimate storage for BTParallelScanDescData
*/
Size
-btestimateparallelscan(int nkeys, int norderbys)
+btestimateparallelscan(Relation rel, int nkeys, int norderbys)
+{
+ int16 nkeyatts = IndexRelationGetNumberOfKeyAttributes(rel);
+ Size estnbtreeshared,
+ genericattrspace;
+
+ /*
+ * Pessimistically assume that every input scan key will be output with
+ * its own SAOP array
+ */
+ estnbtreeshared = offsetof(BTParallelScanDescData, btps_arrElems) +
+ sizeof(int) * nkeys;
+
+ /* Single column indexes cannot possibly use a skip array */
+ if (nkeyatts == 1)
+ return estnbtreeshared;
+
+ /*
+ * Pessimistically assume that all attributes prior to the least
+ * significant attribute require a skip array (and an associated key)
+ */
+ genericattrspace = datumEstimateSpace((Datum) 0, false, true,
+ sizeof(Datum));
+ for (int attnum = 1; attnum < nkeyatts; attnum++)
+ {
+ CompactAttribute *attr;
+
+ /*
+ * We make the conservative assumption that every index column will
+ * also require a skip array.
+ *
+ * Every skip array must have space to store its scan key's sk_flags.
+ */
+ estnbtreeshared = add_size(estnbtreeshared, sizeof(int));
+
+ /* Consider space required to store a datum of opclass input type */
+ attr = TupleDescCompactAttr(rel->rd_att, attnum - 1);
+ if (attr->attbyval)
+ {
+ /* This index attribute stores pass-by-value datums */
+ Size estfixed = datumEstimateSpace((Datum) 0, false,
+ true, attr->attlen);
+
+ estnbtreeshared = add_size(estnbtreeshared, estfixed);
+ continue;
+ }
+
+ /*
+ * This index attribute stores pass-by-reference datums.
+ *
+ * Assume that serializing this array will use just as much space as a
+ * pass-by-value datum, in addition to space for the largest possible
+ * whole index tuple (this is not just a per-datum portion of the
+ * largest possible tuple because that'd be almost as large anyway).
+ *
+ * This is quite conservative, but it's not clear how we could do much
+ * better. The executor requires an up-front storage request size
+ * that reliably covers the scan's high watermark memory usage. We
+ * can't be sure of the real high watermark until the scan is over.
+ */
+ estnbtreeshared = add_size(estnbtreeshared, genericattrspace);
+ estnbtreeshared = add_size(estnbtreeshared, BTMaxItemSize);
+ }
+
+ return estnbtreeshared;
+}
+
+/*
+ * _bt_parallel_serialize_arrays() -- Serialize parallel array state.
+ *
+ * Caller must have exclusively locked btscan->btps_lock when called.
+ */
+static void
+_bt_parallel_serialize_arrays(Relation rel, BTParallelScanDesc btscan,
+ BTScanOpaque so)
+{
+ char *datumshared;
+
+ /* Space for serialized datums begins immediately after btps_arrElems[] */
+ datumshared = ((char *) &btscan->btps_arrElems[so->numArrayKeys]);
+ for (int i = 0; i < so->numArrayKeys; i++)
+ {
+ BTArrayKeyInfo *array = &so->arrayKeys[i];
+ ScanKey skey = &so->keyData[array->scan_key];
+
+ if (array->num_elems != -1)
+ {
+ /* Save SAOP array's cur_elem (no need to copy key/datum) */
+ Assert(!(skey->sk_flags & SK_BT_SKIP));
+ btscan->btps_arrElems[i] = array->cur_elem;
+ continue;
+ }
+
+ /* Save all mutable state associated with skip array's key */
+ Assert(skey->sk_flags & SK_BT_SKIP);
+ memcpy(datumshared, &skey->sk_flags, sizeof(int));
+ datumshared += sizeof(int);
+
+ if (skey->sk_flags & (SK_BT_MINVAL | SK_BT_MAXVAL))
+ {
+ /* No sk_argument datum to serialize */
+ Assert(skey->sk_argument == 0);
+ continue;
+ }
+
+ datumSerialize(skey->sk_argument, (skey->sk_flags & SK_ISNULL) != 0,
+ array->attbyval, array->attlen, &datumshared);
+ }
+}
+
+/*
+ * _bt_parallel_restore_arrays() -- Restore serialized parallel array state.
+ *
+ * Caller must have exclusively locked btscan->btps_lock when called.
+ */
+static void
+_bt_parallel_restore_arrays(Relation rel, BTParallelScanDesc btscan,
+ BTScanOpaque so)
{
- /* Pessimistically assume all input scankeys will be output with arrays */
- return offsetof(BTParallelScanDescData, btps_arrElems) + sizeof(int) * nkeys;
+ char *datumshared;
+
+ /* Space for serialized datums begins immediately after btps_arrElems[] */
+ datumshared = ((char *) &btscan->btps_arrElems[so->numArrayKeys]);
+ for (int i = 0; i < so->numArrayKeys; i++)
+ {
+ BTArrayKeyInfo *array = &so->arrayKeys[i];
+ ScanKey skey = &so->keyData[array->scan_key];
+ bool isnull;
+
+ if (array->num_elems != -1)
+ {
+ /* Restore SAOP array using its saved cur_elem */
+ Assert(!(skey->sk_flags & SK_BT_SKIP));
+ array->cur_elem = btscan->btps_arrElems[i];
+ skey->sk_argument = array->elem_values[array->cur_elem];
+ continue;
+ }
+
+ /* Restore skip array by restoring its key directly */
+ if (!array->attbyval && skey->sk_argument)
+ pfree(DatumGetPointer(skey->sk_argument));
+ skey->sk_argument = (Datum) 0;
+ memcpy(&skey->sk_flags, datumshared, sizeof(int));
+ datumshared += sizeof(int);
+
+ Assert(skey->sk_flags & SK_BT_SKIP);
+
+ if (skey->sk_flags & (SK_BT_MINVAL | SK_BT_MAXVAL))
+ {
+ /* No sk_argument datum to restore */
+ continue;
+ }
+
+ skey->sk_argument = datumRestore(&datumshared, &isnull);
+ if (isnull)
+ {
+ Assert(skey->sk_argument == 0);
+ Assert(skey->sk_flags & SK_SEARCHNULL);
+ Assert(skey->sk_flags & SK_ISNULL);
+ }
+ }
}
/*
@@ -613,6 +783,7 @@ bool
_bt_parallel_seize(IndexScanDesc scan, BlockNumber *next_scan_page,
BlockNumber *last_curr_page, bool first)
{
+ Relation rel = scan->indexRelation;
BTScanOpaque so = (BTScanOpaque) scan->opaque;
bool exit_loop = false,
status = true,
@@ -679,14 +850,9 @@ _bt_parallel_seize(IndexScanDesc scan, BlockNumber *next_scan_page,
{
/* Can start scheduled primitive scan right away, so do so */
btscan->btps_pageStatus = BTPARALLEL_ADVANCING;
- for (int i = 0; i < so->numArrayKeys; i++)
- {
- BTArrayKeyInfo *array = &so->arrayKeys[i];
- ScanKey skey = &so->keyData[array->scan_key];
- array->cur_elem = btscan->btps_arrElems[i];
- skey->sk_argument = array->elem_values[array->cur_elem];
- }
+ /* Restore scan's array keys from serialized values */
+ _bt_parallel_restore_arrays(rel, btscan, so);
exit_loop = true;
}
else
@@ -831,6 +997,7 @@ _bt_parallel_done(IndexScanDesc scan)
void
_bt_parallel_primscan_schedule(IndexScanDesc scan, BlockNumber curr_page)
{
+ Relation rel = scan->indexRelation;
BTScanOpaque so = (BTScanOpaque) scan->opaque;
ParallelIndexScanDesc parallel_scan = scan->parallel_scan;
BTParallelScanDesc btscan;
@@ -849,12 +1016,7 @@ _bt_parallel_primscan_schedule(IndexScanDesc scan, BlockNumber curr_page)
btscan->btps_pageStatus = BTPARALLEL_NEED_PRIMSCAN;
/* Serialize scan's current array keys */
- for (int i = 0; i < so->numArrayKeys; i++)
- {
- BTArrayKeyInfo *array = &so->arrayKeys[i];
-
- btscan->btps_arrElems[i] = array->cur_elem;
- }
+ _bt_parallel_serialize_arrays(rel, btscan, so);
}
LWLockRelease(&btscan->btps_lock);
}
diff --git a/src/backend/access/nbtree/nbtsearch.c b/src/backend/access/nbtree/nbtsearch.c
index 3d46fb5df78..1ef2cb2b55e 100644
--- a/src/backend/access/nbtree/nbtsearch.c
+++ b/src/backend/access/nbtree/nbtsearch.c
@@ -983,7 +983,21 @@ _bt_first(IndexScanDesc scan, ScanDirection dir)
* one we use --- by definition, they are either redundant or
* contradictory.
*
- * Any regular (not SK_SEARCHNULL) key implies a NOT NULL qualifier.
+ * In practice we rarely see any "attribute boundary key gaps" here.
+ * Preprocessing can usually backfill skip array keys for any attributes
+ * that were omitted from the original scan->keyData[] input keys. All
+ * array keys are always considered = keys, but we'll sometimes need to
+ * treat the current key value as if we were using an inequality strategy.
+ * This happens with range skip arrays, which store inequality keys in the
+ * array's low_compare/high_compare fields (used to find the first/last
+ * set of matches, when = key will lack a usable sk_argument value).
+ * These are always preferred over any redundant "standard" inequality
+ * keys on the same column (per the usual rule about preferring = keys).
+ * Note also that any column with an = skip array key can never have an
+ * additional, contradictory = key.
+ *
+ * All keys (with the exception of SK_SEARCHNULL keys and SK_BT_SKIP
+ * array keys whose array is "null_elem=true") imply a NOT NULL qualifier.
* If the index stores nulls at the end of the index we'll be starting
* from, and we have no boundary key for the column (which means the key
* we deduced NOT NULL from is an inequality key that constrains the other
@@ -1040,8 +1054,54 @@ _bt_first(IndexScanDesc scan, ScanDirection dir)
if (i >= so->numberOfKeys || cur->sk_attno != curattr)
{
/*
- * Done looking at keys for curattr. If we didn't find a
- * usable boundary key, see if we can deduce a NOT NULL key.
+ * Done looking at keys for curattr.
+ *
+ * If this is a scan key for a skip array whose current
+ * element is MINVAL, choose low_compare (when scanning
+ * backwards it'll be MAXVAL, and we'll choose high_compare).
+ *
+ * Note: if the array's low_compare key makes 'chosen' NULL,
+ * then we behave as if the array's first element is -inf,
+ * except when !array->null_elem implies a usable NOT NULL
+ * constraint.
+ */
+ if (chosen != NULL &&
+ (chosen->sk_flags & (SK_BT_MINVAL | SK_BT_MAXVAL)))
+ {
+ int ikey = chosen - so->keyData;
+ ScanKey skipequalitykey = chosen;
+ BTArrayKeyInfo *array = NULL;
+
+ for (int arridx = 0; arridx < so->numArrayKeys; arridx++)
+ {
+ array = &so->arrayKeys[arridx];
+ if (array->scan_key == ikey)
+ break;
+ }
+
+ if (ScanDirectionIsForward(dir))
+ {
+ Assert(!(skipequalitykey->sk_flags & SK_BT_MAXVAL));
+ chosen = array->low_compare;
+ }
+ else
+ {
+ Assert(!(skipequalitykey->sk_flags & SK_BT_MINVAL));
+ chosen = array->high_compare;
+ }
+
+ Assert(chosen == NULL ||
+ chosen->sk_attno == skipequalitykey->sk_attno);
+
+ if (!array->null_elem)
+ impliesNN = skipequalitykey;
+ else
+ Assert(chosen == NULL && impliesNN == NULL);
+ }
+
+ /*
+ * If we didn't find a usable boundary key, see if we can
+ * deduce a NOT NULL key
*/
if (chosen == NULL && impliesNN != NULL &&
((impliesNN->sk_flags & SK_BT_NULLS_FIRST) ?
@@ -1084,9 +1144,40 @@ _bt_first(IndexScanDesc scan, ScanDirection dir)
break;
/*
- * Done if that was the last attribute, or if next key is not
- * in sequence (implying no boundary key is available for the
- * next attribute).
+ * If the key that we just added to startKeys[] is a skip
+ * array = key whose current element is marked NEXT or PRIOR,
+ * make strat_total > or < (and stop adding boundary keys).
+ * This can only happen with opclasses that lack skip support.
+ */
+ if (chosen->sk_flags & (SK_BT_NEXT | SK_BT_PRIOR))
+ {
+ Assert(chosen->sk_flags & SK_BT_SKIP);
+ Assert(strat_total == BTEqualStrategyNumber);
+
+ if (ScanDirectionIsForward(dir))
+ {
+ Assert(!(chosen->sk_flags & SK_BT_PRIOR));
+ strat_total = BTGreaterStrategyNumber;
+ }
+ else
+ {
+ Assert(!(chosen->sk_flags & SK_BT_NEXT));
+ strat_total = BTLessStrategyNumber;
+ }
+
+ /*
+ * We're done. We'll never find an exact = match for a
+ * NEXT or PRIOR sentinel sk_argument value. There's no
+ * sense in trying to add more keys to startKeys[].
+ */
+ break;
+ }
+
+ /*
+ * Done if that was the last scan key output by preprocessing.
+ * Also done if there is a gap index attribute that lacks a
+ * usable key (only possible when preprocessing was unable to
+ * generate a skip array key to "fill in the gap").
*/
if (i >= so->numberOfKeys ||
cur->sk_attno != curattr + 1)
@@ -1581,31 +1672,10 @@ _bt_readpage(IndexScanDesc scan, ScanDirection dir, OffsetNumber offnum,
* We skip this for the first page read by each (primitive) scan, to avoid
* slowing down point queries. They typically don't stand to gain much
* when the optimization can be applied, and are more likely to notice the
- * overhead of the precheck.
- *
- * The optimization is unsafe and must be avoided whenever _bt_checkkeys
- * just set a low-order required array's key to the best available match
- * for a truncated -inf attribute value from the prior page's high key
- * (array element 0 is always the best available match in this scenario).
- * It's quite likely that matches for array element 0 begin on this page,
- * but the start of matches won't necessarily align with page boundaries.
- * When the start of matches is somewhere in the middle of this page, it
- * would be wrong to treat page's final non-pivot tuple as representative.
- * Doing so might lead us to treat some of the page's earlier tuples as
- * being part of a group of tuples thought to satisfy the required keys.
- *
- * Note: Conversely, in the case where the scan's arrays just advanced
- * using the prior page's HIKEY _without_ advancement setting scanBehind,
- * the start of matches must be aligned with page boundaries, which makes
- * it safe to attempt the optimization here now. It's also safe when the
- * prior page's HIKEY simply didn't need to advance any required array. In
- * both cases we can safely assume that the _first_ tuple from this page
- * must be >= the current set of array keys/equality constraints. And so
- * if the final tuple is == those same keys (and also satisfies any
- * required < or <= strategy scan keys) during the precheck, we can safely
- * assume that this must also be true of all earlier tuples from the page.
+ * overhead of the precheck. Also avoid it during scans with array keys,
+ * which might be using skip scan (XXX fixed in next commit).
*/
- if (!pstate.firstpage && !so->scanBehind && minoff < maxoff)
+ if (!pstate.firstpage && !arrayKeys && minoff < maxoff)
{
ItemId iid;
IndexTuple itup;
diff --git a/src/backend/access/nbtree/nbtutils.c b/src/backend/access/nbtree/nbtutils.c
index 2aee9bbf67d..108030a8ee7 100644
--- a/src/backend/access/nbtree/nbtutils.c
+++ b/src/backend/access/nbtree/nbtutils.c
@@ -30,6 +30,17 @@
static inline int32 _bt_compare_array_skey(FmgrInfo *orderproc,
Datum tupdatum, bool tupnull,
Datum arrdatum, ScanKey cur);
+static void _bt_binsrch_skiparray_skey(bool cur_elem_trig, ScanDirection dir,
+ Datum tupdatum, bool tupnull,
+ BTArrayKeyInfo *array, ScanKey cur,
+ int32 *set_elem_result);
+static void _bt_skiparray_set_element(Relation rel, ScanKey skey, BTArrayKeyInfo *array,
+ int32 set_elem_result, Datum tupdatum, bool tupnull);
+static void _bt_skiparray_set_isnull(Relation rel, ScanKey skey, BTArrayKeyInfo *array);
+static void _bt_array_set_low_or_high(Relation rel, ScanKey skey,
+ BTArrayKeyInfo *array, bool low_not_high);
+static bool _bt_array_decrement(Relation rel, ScanKey skey, BTArrayKeyInfo *array);
+static bool _bt_array_increment(Relation rel, ScanKey skey, BTArrayKeyInfo *array);
static bool _bt_advance_array_keys_increment(IndexScanDesc scan, ScanDirection dir);
static void _bt_rewind_nonrequired_arrays(IndexScanDesc scan, ScanDirection dir);
static bool _bt_tuple_before_array_skeys(IndexScanDesc scan, ScanDirection dir,
@@ -207,6 +218,7 @@ _bt_compare_array_skey(FmgrInfo *orderproc,
int32 result = 0;
Assert(cur->sk_strategy == BTEqualStrategyNumber);
+ Assert(!(cur->sk_flags & (SK_BT_MINVAL | SK_BT_MAXVAL)));
if (tupnull) /* NULL tupdatum */
{
@@ -283,6 +295,8 @@ _bt_binsrch_array_skey(FmgrInfo *orderproc,
Datum arrdatum;
Assert(cur->sk_flags & SK_SEARCHARRAY);
+ Assert(!(cur->sk_flags & SK_BT_SKIP));
+ Assert(!(cur->sk_flags & SK_ISNULL)); /* SAOP arrays never have NULLs */
Assert(cur->sk_strategy == BTEqualStrategyNumber);
if (cur_elem_trig)
@@ -406,6 +420,186 @@ _bt_binsrch_array_skey(FmgrInfo *orderproc,
}
/*
+ * _bt_binsrch_skiparray_skey() -- "Binary search" within a skip array
+ *
+ * Does not return an index into the array, since skip arrays don't really
+ * contain elements (they generate their array elements procedurally instead).
+ * Our interface matches that of _bt_binsrch_array_skey in every other way.
+ *
+ * Sets *set_elem_result just like _bt_binsrch_array_skey would with a true
+ * array. The value 0 indicates that tupdatum/tupnull is within the range of
+ * the skip array. We return -1 when tupdatum/tupnull is lower that any value
+ * within the range of the array, and 1 when it is higher than every value.
+ * Caller should pass *set_elem_result to _bt_skiparray_set_element to advance
+ * the array.
+ *
+ * cur_elem_trig indicates if array advancement was triggered by this array's
+ * scan key. We use this to optimize-away comparisons that are known by our
+ * caller to be unnecessary from context, just like _bt_binsrch_array_skey.
+ */
+static void
+_bt_binsrch_skiparray_skey(bool cur_elem_trig, ScanDirection dir,
+ Datum tupdatum, bool tupnull,
+ BTArrayKeyInfo *array, ScanKey cur,
+ int32 *set_elem_result)
+{
+ Assert(cur->sk_flags & SK_BT_SKIP);
+ Assert(cur->sk_flags & SK_SEARCHARRAY);
+ Assert(cur->sk_flags & SK_BT_REQFWD);
+ Assert(array->num_elems == -1);
+ Assert(!ScanDirectionIsNoMovement(dir));
+
+ if (array->null_elem)
+ {
+ Assert(!array->low_compare && !array->high_compare);
+
+ *set_elem_result = 0;
+ return;
+ }
+
+ if (tupnull) /* NULL tupdatum */
+ {
+ if (cur->sk_flags & SK_BT_NULLS_FIRST)
+ *set_elem_result = -1; /* NULL "<" NOT_NULL */
+ else
+ *set_elem_result = 1; /* NULL ">" NOT_NULL */
+ return;
+ }
+
+ /*
+ * Array inequalities determine whether tupdatum is within the range of
+ * caller's skip array
+ */
+ *set_elem_result = 0;
+ if (ScanDirectionIsForward(dir))
+ {
+ /*
+ * Evaluate low_compare first (unless cur_elem_trig tells us that it
+ * cannot possibly fail to be satisfied), then evaluate high_compare
+ */
+ if (!cur_elem_trig && array->low_compare &&
+ !DatumGetBool(FunctionCall2Coll(&array->low_compare->sk_func,
+ array->low_compare->sk_collation,
+ tupdatum,
+ array->low_compare->sk_argument)))
+ *set_elem_result = -1;
+ else if (array->high_compare &&
+ !DatumGetBool(FunctionCall2Coll(&array->high_compare->sk_func,
+ array->high_compare->sk_collation,
+ tupdatum,
+ array->high_compare->sk_argument)))
+ *set_elem_result = 1;
+ }
+ else
+ {
+ /*
+ * Evaluate high_compare first (unless cur_elem_trig tells us that it
+ * cannot possibly fail to be satisfied), then evaluate low_compare
+ */
+ if (!cur_elem_trig && array->high_compare &&
+ !DatumGetBool(FunctionCall2Coll(&array->high_compare->sk_func,
+ array->high_compare->sk_collation,
+ tupdatum,
+ array->high_compare->sk_argument)))
+ *set_elem_result = 1;
+ else if (array->low_compare &&
+ !DatumGetBool(FunctionCall2Coll(&array->low_compare->sk_func,
+ array->low_compare->sk_collation,
+ tupdatum,
+ array->low_compare->sk_argument)))
+ *set_elem_result = -1;
+ }
+
+ /*
+ * Assert that any keys that were assumed to be satisfied already (due to
+ * caller passing cur_elem_trig=true) really are satisfied as expected
+ */
+#ifdef USE_ASSERT_CHECKING
+ if (cur_elem_trig)
+ {
+ if (ScanDirectionIsForward(dir) && array->low_compare)
+ Assert(DatumGetBool(FunctionCall2Coll(&array->low_compare->sk_func,
+ array->low_compare->sk_collation,
+ tupdatum,
+ array->low_compare->sk_argument)));
+
+ if (ScanDirectionIsBackward(dir) && array->high_compare)
+ Assert(DatumGetBool(FunctionCall2Coll(&array->high_compare->sk_func,
+ array->high_compare->sk_collation,
+ tupdatum,
+ array->high_compare->sk_argument)));
+ }
+#endif
+}
+
+/*
+ * _bt_skiparray_set_element() -- Set skip array scan key's sk_argument
+ *
+ * Caller passes set_elem_result returned by _bt_binsrch_skiparray_skey for
+ * caller's tupdatum/tupnull.
+ *
+ * We copy tupdatum/tupnull into skey's sk_argument iff set_elem_result == 0.
+ * Otherwise, we set skey to either the lowest or highest value that's within
+ * the range of caller's skip array (whichever is the best available match to
+ * tupdatum/tupnull that is still within the range of the skip array according
+ * to _bt_binsrch_skiparray_skey/set_elem_result).
+ */
+static void
+_bt_skiparray_set_element(Relation rel, ScanKey skey, BTArrayKeyInfo *array,
+ int32 set_elem_result, Datum tupdatum, bool tupnull)
+{
+ Assert(skey->sk_flags & SK_BT_SKIP);
+ Assert(skey->sk_flags & SK_SEARCHARRAY);
+
+ if (set_elem_result)
+ {
+ /* tupdatum/tupnull is out of the range of the skip array */
+ Assert(!array->null_elem);
+
+ _bt_array_set_low_or_high(rel, skey, array, set_elem_result < 0);
+ return;
+ }
+
+ /* Advance skip array to tupdatum (or tupnull) value */
+ if (unlikely(tupnull))
+ {
+ _bt_skiparray_set_isnull(rel, skey, array);
+ return;
+ }
+
+ /* Free memory previously allocated for sk_argument if needed */
+ if (!array->attbyval && skey->sk_argument)
+ pfree(DatumGetPointer(skey->sk_argument));
+
+ /* tupdatum becomes new sk_argument/new current element */
+ skey->sk_flags &= ~(SK_SEARCHNULL | SK_ISNULL |
+ SK_BT_MINVAL | SK_BT_MAXVAL |
+ SK_BT_NEXT | SK_BT_PRIOR);
+ skey->sk_argument = datumCopy(tupdatum, array->attbyval, array->attlen);
+}
+
+/*
+ * _bt_skiparray_set_isnull() -- set skip array scan key to NULL
+ */
+static void
+_bt_skiparray_set_isnull(Relation rel, ScanKey skey, BTArrayKeyInfo *array)
+{
+ Assert(skey->sk_flags & SK_BT_SKIP);
+ Assert(skey->sk_flags & SK_SEARCHARRAY);
+ Assert(array->null_elem && !array->low_compare && !array->high_compare);
+
+ /* Free memory previously allocated for sk_argument if needed */
+ if (!array->attbyval && skey->sk_argument)
+ pfree(DatumGetPointer(skey->sk_argument));
+
+ /* NULL becomes new sk_argument/new current element */
+ skey->sk_argument = (Datum) 0;
+ skey->sk_flags &= ~(SK_BT_MINVAL | SK_BT_MAXVAL |
+ SK_BT_NEXT | SK_BT_PRIOR);
+ skey->sk_flags |= (SK_SEARCHNULL | SK_ISNULL);
+}
+
+/*
* _bt_start_array_keys() -- Initialize array keys at start of a scan
*
* Set up the cur_elem counters and fill in the first sk_argument value for
@@ -414,30 +608,356 @@ _bt_binsrch_array_skey(FmgrInfo *orderproc,
void
_bt_start_array_keys(IndexScanDesc scan, ScanDirection dir)
{
+ Relation rel = scan->indexRelation;
BTScanOpaque so = (BTScanOpaque) scan->opaque;
- int i;
Assert(so->numArrayKeys);
Assert(so->qual_ok);
- for (i = 0; i < so->numArrayKeys; i++)
+ for (int i = 0; i < so->numArrayKeys; i++)
{
- BTArrayKeyInfo *curArrayKey = &so->arrayKeys[i];
- ScanKey skey = &so->keyData[curArrayKey->scan_key];
+ BTArrayKeyInfo *array = &so->arrayKeys[i];
+ ScanKey skey = &so->keyData[array->scan_key];
- Assert(curArrayKey->num_elems > 0);
Assert(skey->sk_flags & SK_SEARCHARRAY);
- if (ScanDirectionIsBackward(dir))
- curArrayKey->cur_elem = curArrayKey->num_elems - 1;
- else
- curArrayKey->cur_elem = 0;
- skey->sk_argument = curArrayKey->elem_values[curArrayKey->cur_elem];
+ _bt_array_set_low_or_high(rel, skey, array,
+ ScanDirectionIsForward(dir));
}
so->scanBehind = so->oppositeDirCheck = false; /* reset */
}
/*
+ * _bt_array_set_low_or_high() -- Set array scan key to lowest/highest element
+ *
+ * Caller also passes associated scan key, which will have its argument set to
+ * the lowest/highest array value in passing.
+ */
+static void
+_bt_array_set_low_or_high(Relation rel, ScanKey skey, BTArrayKeyInfo *array,
+ bool low_not_high)
+{
+ Assert(skey->sk_flags & SK_SEARCHARRAY);
+
+ if (array->num_elems != -1)
+ {
+ /* set low or high element for SAOP array */
+ int set_elem = 0;
+
+ Assert(!(skey->sk_flags & SK_BT_SKIP));
+
+ if (!low_not_high)
+ set_elem = array->num_elems - 1;
+
+ /*
+ * Just copy over array datum (only skip arrays require freeing and
+ * allocating memory for sk_argument)
+ */
+ array->cur_elem = set_elem;
+ skey->sk_argument = array->elem_values[set_elem];
+
+ return;
+ }
+
+ /* set low or high element for skip array */
+ Assert(skey->sk_flags & SK_BT_SKIP);
+ Assert(array->num_elems == -1);
+
+ /* Free memory previously allocated for sk_argument if needed */
+ if (!array->attbyval && skey->sk_argument)
+ pfree(DatumGetPointer(skey->sk_argument));
+
+ /* Reset flags */
+ skey->sk_argument = (Datum) 0;
+ skey->sk_flags &= ~(SK_SEARCHNULL | SK_ISNULL |
+ SK_BT_MINVAL | SK_BT_MAXVAL |
+ SK_BT_NEXT | SK_BT_PRIOR);
+
+ if (array->null_elem &&
+ (low_not_high == ((skey->sk_flags & SK_BT_NULLS_FIRST) != 0)))
+ {
+ /* Requested element (either lowest or highest) has the value NULL */
+ skey->sk_flags |= (SK_SEARCHNULL | SK_ISNULL);
+ }
+ else if (low_not_high)
+ {
+ /* Setting array to lowest element (according to low_compare) */
+ skey->sk_flags |= SK_BT_MINVAL;
+ }
+ else
+ {
+ /* Setting array to highest element (according to high_compare) */
+ skey->sk_flags |= SK_BT_MAXVAL;
+ }
+}
+
+/*
+ * _bt_array_decrement() -- decrement array scan key's sk_argument
+ *
+ * Return value indicates whether caller's array was successfully decremented.
+ * Cannot decrement an array whose current element is already the first one.
+ */
+static bool
+_bt_array_decrement(Relation rel, ScanKey skey, BTArrayKeyInfo *array)
+{
+ bool uflow = false;
+ Datum dec_sk_argument;
+
+ Assert(skey->sk_flags & SK_SEARCHARRAY);
+ Assert(!(skey->sk_flags & (SK_BT_MAXVAL | SK_BT_NEXT | SK_BT_PRIOR)));
+
+ /* SAOP array? */
+ if (array->num_elems != -1)
+ {
+ Assert(!(skey->sk_flags & (SK_BT_SKIP | SK_BT_MINVAL | SK_BT_MAXVAL)));
+ if (array->cur_elem > 0)
+ {
+ /*
+ * Just decrement current element, and assign its datum to skey
+ * (only skip arrays need us to free existing sk_argument memory)
+ */
+ array->cur_elem--;
+ skey->sk_argument = array->elem_values[array->cur_elem];
+
+ /* Successfully decremented array */
+ return true;
+ }
+
+ /* Cannot decrement to before first array element */
+ return false;
+ }
+
+ /* Nope, this is a skip array */
+ Assert(skey->sk_flags & SK_BT_SKIP);
+
+ /*
+ * The sentinel value that represents the minimum value within the range
+ * of a skip array (often just -inf) is never decrementable
+ */
+ if (skey->sk_flags & SK_BT_MINVAL)
+ return false;
+
+ /*
+ * When the current array element is NULL, and the lowest sorting value in
+ * the index is also NULL, we cannot decrement before first array element
+ */
+ if ((skey->sk_flags & SK_ISNULL) && (skey->sk_flags & SK_BT_NULLS_FIRST))
+ return false;
+
+ /*
+ * Opclasses without skip support "decrement" the scan key's current
+ * element by setting the PRIOR flag. The true prior value is determined
+ * by repositioning to the last index tuple < existing sk_argument/current
+ * array element. Note that this works in the usual way when the scan key
+ * is already marked ISNULL (i.e. when the current element is NULL).
+ */
+ if (!array->sksup)
+ {
+ /* Successfully "decremented" array */
+ skey->sk_flags |= SK_BT_PRIOR;
+ return true;
+ }
+
+ /*
+ * Opclasses with skip support directly decrement sk_argument
+ */
+ if (skey->sk_flags & SK_ISNULL)
+ {
+ Assert(!(skey->sk_flags & SK_BT_NULLS_FIRST));
+
+ /*
+ * Existing sk_argument/array element is NULL (for an IS NULL qual).
+ *
+ * "Decrement" from NULL to the high_elem value provided by opclass
+ * skip support routine.
+ */
+ skey->sk_flags &= ~(SK_SEARCHNULL | SK_ISNULL);
+ skey->sk_argument = datumCopy(array->sksup->high_elem,
+ array->attbyval, array->attlen);
+ return true;
+ }
+
+ /*
+ * Ask opclass support routine to provide decremented copy of existing
+ * non-NULL sk_argument
+ */
+ dec_sk_argument = array->sksup->decrement(rel, skey->sk_argument, &uflow);
+ if (unlikely(uflow))
+ {
+ /* dec_sk_argument has undefined value (so no pfree) */
+ if (array->null_elem && (skey->sk_flags & SK_BT_NULLS_FIRST))
+ {
+ _bt_skiparray_set_isnull(rel, skey, array);
+
+ /* Successfully "decremented" array to NULL */
+ return true;
+ }
+
+ /* Cannot decrement to before first array element */
+ return false;
+ }
+
+ /*
+ * Successfully decremented sk_argument to a non-NULL value. Make sure
+ * that the decremented value is still within the range of the array.
+ */
+ if (array->low_compare &&
+ !DatumGetBool(FunctionCall2Coll(&array->low_compare->sk_func,
+ array->low_compare->sk_collation,
+ dec_sk_argument,
+ array->low_compare->sk_argument)))
+ {
+ /* Keep existing sk_argument after all */
+ if (!array->attbyval)
+ pfree(DatumGetPointer(dec_sk_argument));
+
+ /* Cannot decrement to before first array element */
+ return false;
+ }
+
+ /* Accept value returned by opclass decrement callback */
+ if (!array->attbyval && skey->sk_argument)
+ pfree(DatumGetPointer(skey->sk_argument));
+ skey->sk_argument = dec_sk_argument;
+
+ /* Successfully decremented array */
+ return true;
+}
+
+/*
+ * _bt_array_increment() -- increment array scan key's sk_argument
+ *
+ * Return value indicates whether caller's array was successfully incremented.
+ * Cannot increment an array whose current element is already the final one.
+ */
+static bool
+_bt_array_increment(Relation rel, ScanKey skey, BTArrayKeyInfo *array)
+{
+ bool oflow = false;
+ Datum inc_sk_argument;
+
+ Assert(skey->sk_flags & SK_SEARCHARRAY);
+ Assert(!(skey->sk_flags & (SK_BT_MINVAL | SK_BT_NEXT | SK_BT_PRIOR)));
+
+ /* SAOP array? */
+ if (array->num_elems != -1)
+ {
+ Assert(!(skey->sk_flags & (SK_BT_SKIP | SK_BT_MINVAL | SK_BT_MAXVAL)));
+ if (array->cur_elem < array->num_elems - 1)
+ {
+ /*
+ * Just increment current element, and assign its datum to skey
+ * (only skip arrays need us to free existing sk_argument memory)
+ */
+ array->cur_elem++;
+ skey->sk_argument = array->elem_values[array->cur_elem];
+
+ /* Successfully incremented array */
+ return true;
+ }
+
+ /* Cannot increment past final array element */
+ return false;
+ }
+
+ /* Nope, this is a skip array */
+ Assert(skey->sk_flags & SK_BT_SKIP);
+
+ /*
+ * The sentinel value that represents the maximum value within the range
+ * of a skip array (often just +inf) is never incrementable
+ */
+ if (skey->sk_flags & SK_BT_MAXVAL)
+ return false;
+
+ /*
+ * When the current array element is NULL, and the highest sorting value
+ * in the index is also NULL, we cannot increment past the final element
+ */
+ if ((skey->sk_flags & SK_ISNULL) && !(skey->sk_flags & SK_BT_NULLS_FIRST))
+ return false;
+
+ /*
+ * Opclasses without skip support "increment" the scan key's current
+ * element by setting the NEXT flag. The true next value is determined by
+ * repositioning to the first index tuple > existing sk_argument/current
+ * array element. Note that this works in the usual way when the scan key
+ * is already marked ISNULL (i.e. when the current element is NULL).
+ */
+ if (!array->sksup)
+ {
+ /* Successfully "incremented" array */
+ skey->sk_flags |= SK_BT_NEXT;
+ return true;
+ }
+
+ /*
+ * Opclasses with skip support directly increment sk_argument
+ */
+ if (skey->sk_flags & SK_ISNULL)
+ {
+ Assert(skey->sk_flags & SK_BT_NULLS_FIRST);
+
+ /*
+ * Existing sk_argument/array element is NULL (for an IS NULL qual).
+ *
+ * "Increment" from NULL to the low_elem value provided by opclass
+ * skip support routine.
+ */
+ skey->sk_flags &= ~(SK_SEARCHNULL | SK_ISNULL);
+ skey->sk_argument = datumCopy(array->sksup->low_elem,
+ array->attbyval, array->attlen);
+ return true;
+ }
+
+ /*
+ * Ask opclass support routine to provide incremented copy of existing
+ * non-NULL sk_argument
+ */
+ inc_sk_argument = array->sksup->increment(rel, skey->sk_argument, &oflow);
+ if (unlikely(oflow))
+ {
+ /* inc_sk_argument has undefined value (so no pfree) */
+ if (array->null_elem && !(skey->sk_flags & SK_BT_NULLS_FIRST))
+ {
+ _bt_skiparray_set_isnull(rel, skey, array);
+
+ /* Successfully "incremented" array to NULL */
+ return true;
+ }
+
+ /* Cannot increment past final array element */
+ return false;
+ }
+
+ /*
+ * Successfully incremented sk_argument to a non-NULL value. Make sure
+ * that the incremented value is still within the range of the array.
+ */
+ if (array->high_compare &&
+ !DatumGetBool(FunctionCall2Coll(&array->high_compare->sk_func,
+ array->high_compare->sk_collation,
+ inc_sk_argument,
+ array->high_compare->sk_argument)))
+ {
+ /* Keep existing sk_argument after all */
+ if (!array->attbyval)
+ pfree(DatumGetPointer(inc_sk_argument));
+
+ /* Cannot increment past final array element */
+ return false;
+ }
+
+ /* Accept value returned by opclass increment callback */
+ if (!array->attbyval && skey->sk_argument)
+ pfree(DatumGetPointer(skey->sk_argument));
+ skey->sk_argument = inc_sk_argument;
+
+ /* Successfully incremented array */
+ return true;
+}
+
+/*
* _bt_advance_array_keys_increment() -- Advance to next set of array elements
*
* Advances the array keys by a single increment in the current scan
@@ -452,6 +972,7 @@ _bt_start_array_keys(IndexScanDesc scan, ScanDirection dir)
static bool
_bt_advance_array_keys_increment(IndexScanDesc scan, ScanDirection dir)
{
+ Relation rel = scan->indexRelation;
BTScanOpaque so = (BTScanOpaque) scan->opaque;
/*
@@ -461,29 +982,30 @@ _bt_advance_array_keys_increment(IndexScanDesc scan, ScanDirection dir)
*/
for (int i = so->numArrayKeys - 1; i >= 0; i--)
{
- BTArrayKeyInfo *curArrayKey = &so->arrayKeys[i];
- ScanKey skey = &so->keyData[curArrayKey->scan_key];
- int cur_elem = curArrayKey->cur_elem;
- int num_elems = curArrayKey->num_elems;
- bool rolled = false;
+ BTArrayKeyInfo *array = &so->arrayKeys[i];
+ ScanKey skey = &so->keyData[array->scan_key];
- if (ScanDirectionIsForward(dir) && ++cur_elem >= num_elems)
+ if (ScanDirectionIsForward(dir))
{
- cur_elem = 0;
- rolled = true;
+ if (_bt_array_increment(rel, skey, array))
+ return true;
}
- else if (ScanDirectionIsBackward(dir) && --cur_elem < 0)
+ else
{
- cur_elem = num_elems - 1;
- rolled = true;
+ if (_bt_array_decrement(rel, skey, array))
+ return true;
}
- curArrayKey->cur_elem = cur_elem;
- skey->sk_argument = curArrayKey->elem_values[cur_elem];
- if (!rolled)
- return true;
+ /*
+ * Couldn't increment (or decrement) array. Handle array roll over.
+ *
+ * Start over at the array's lowest sorting value (or its highest
+ * value, for backward scans)...
+ */
+ _bt_array_set_low_or_high(rel, skey, array,
+ ScanDirectionIsForward(dir));
- /* Need to advance next array key, if any */
+ /* ...then increment (or decrement) next most significant array */
}
/*
@@ -507,7 +1029,7 @@ _bt_advance_array_keys_increment(IndexScanDesc scan, ScanDirection dir)
}
/*
- * _bt_rewind_nonrequired_arrays() -- Rewind non-required arrays
+ * _bt_rewind_nonrequired_arrays() -- Rewind SAOP arrays not marked required
*
* Called when _bt_advance_array_keys decides to start a new primitive index
* scan on the basis of the current scan position being before the position
@@ -539,10 +1061,15 @@ _bt_advance_array_keys_increment(IndexScanDesc scan, ScanDirection dir)
*
* Note: _bt_verify_arrays_bt_first is called by an assertion to enforce that
* everybody got this right.
+ *
+ * Note: In practice almost all SAOP arrays are marked required during
+ * preprocessing (if necessary by generating skip arrays). It is hardly ever
+ * truly necessary to call here, but consistently doing so is simpler.
*/
static void
_bt_rewind_nonrequired_arrays(IndexScanDesc scan, ScanDirection dir)
{
+ Relation rel = scan->indexRelation;
BTScanOpaque so = (BTScanOpaque) scan->opaque;
int arrayidx = 0;
@@ -550,7 +1077,6 @@ _bt_rewind_nonrequired_arrays(IndexScanDesc scan, ScanDirection dir)
{
ScanKey cur = so->keyData + ikey;
BTArrayKeyInfo *array = NULL;
- int first_elem_dir;
if (!(cur->sk_flags & SK_SEARCHARRAY) ||
cur->sk_strategy != BTEqualStrategyNumber)
@@ -562,16 +1088,10 @@ _bt_rewind_nonrequired_arrays(IndexScanDesc scan, ScanDirection dir)
if ((cur->sk_flags & (SK_BT_REQFWD | SK_BT_REQBKWD)))
continue;
- if (ScanDirectionIsForward(dir))
- first_elem_dir = 0;
- else
- first_elem_dir = array->num_elems - 1;
+ Assert(array->num_elems != -1); /* No non-required skip arrays */
- if (array->cur_elem != first_elem_dir)
- {
- array->cur_elem = first_elem_dir;
- cur->sk_argument = array->elem_values[first_elem_dir];
- }
+ _bt_array_set_low_or_high(rel, cur, array,
+ ScanDirectionIsForward(dir));
}
}
@@ -696,9 +1216,77 @@ _bt_tuple_before_array_skeys(IndexScanDesc scan, ScanDirection dir,
tupdatum = index_getattr(tuple, cur->sk_attno, tupdesc, &tupnull);
- result = _bt_compare_array_skey(&so->orderProcs[ikey],
- tupdatum, tupnull,
- cur->sk_argument, cur);
+ if (likely(!(cur->sk_flags & (SK_BT_MINVAL | SK_BT_MAXVAL))))
+ {
+ /* Scankey has a valid/comparable sk_argument value */
+ result = _bt_compare_array_skey(&so->orderProcs[ikey],
+ tupdatum, tupnull,
+ cur->sk_argument, cur);
+
+ if (result == 0)
+ {
+ /*
+ * Interpret result in a way that takes NEXT/PRIOR into
+ * account
+ */
+ if (cur->sk_flags & SK_BT_NEXT)
+ result = -1;
+ else if (cur->sk_flags & SK_BT_PRIOR)
+ result = 1;
+
+ Assert(result == 0 || (cur->sk_flags & SK_BT_SKIP));
+ }
+ }
+ else
+ {
+ BTArrayKeyInfo *array = NULL;
+
+ /*
+ * Current array element/array = scan key value is a sentinel
+ * value that represents the lowest (or highest) possible value
+ * that's still within the range of the array.
+ *
+ * Like _bt_first, we only see MINVAL keys during forwards scans
+ * (and similarly only see MAXVAL keys during backwards scans).
+ * Even if the scan's direction changes, we'll stop at some higher
+ * order key before we can ever reach any MAXVAL (or MINVAL) keys.
+ * (However, unlike _bt_first we _can_ get to keys marked either
+ * NEXT or PRIOR, regardless of the scan's current direction.)
+ */
+ Assert(ScanDirectionIsForward(dir) ?
+ !(cur->sk_flags & SK_BT_MAXVAL) :
+ !(cur->sk_flags & SK_BT_MINVAL));
+
+ /*
+ * There are no valid sk_argument values in MINVAL/MAXVAL keys.
+ * Check if tupdatum is within the range of skip array instead.
+ */
+ for (int arrayidx = 0; arrayidx < so->numArrayKeys; arrayidx++)
+ {
+ array = &so->arrayKeys[arrayidx];
+ if (array->scan_key == ikey)
+ break;
+ }
+
+ _bt_binsrch_skiparray_skey(false, dir, tupdatum, tupnull,
+ array, cur, &result);
+
+ if (result == 0)
+ {
+ /*
+ * tupdatum satisfies both low_compare and high_compare, so
+ * it's time to advance the array keys.
+ *
+ * Note: It's possible that the skip array will "advance" from
+ * its MINVAL (or MAXVAL) representation to an alternative,
+ * logically equivalent representation of the same value: a
+ * representation where the = key gets a valid datum in its
+ * sk_argument. This is only possible when low_compare uses
+ * the >= strategy (or high_compare uses the <= strategy).
+ */
+ return false;
+ }
+ }
/*
* Does this comparison indicate that caller must _not_ advance the
@@ -1017,18 +1605,9 @@ _bt_advance_array_keys(IndexScanDesc scan, BTReadPageState *pstate,
*/
if (beyond_end_advance)
{
- int final_elem_dir;
-
- if (ScanDirectionIsBackward(dir) || !array)
- final_elem_dir = 0;
- else
- final_elem_dir = array->num_elems - 1;
-
- if (array && array->cur_elem != final_elem_dir)
- {
- array->cur_elem = final_elem_dir;
- cur->sk_argument = array->elem_values[final_elem_dir];
- }
+ if (array)
+ _bt_array_set_low_or_high(rel, cur, array,
+ ScanDirectionIsBackward(dir));
continue;
}
@@ -1053,18 +1632,9 @@ _bt_advance_array_keys(IndexScanDesc scan, BTReadPageState *pstate,
*/
if (!all_required_satisfied || cur->sk_attno > tupnatts)
{
- int first_elem_dir;
-
- if (ScanDirectionIsForward(dir) || !array)
- first_elem_dir = 0;
- else
- first_elem_dir = array->num_elems - 1;
-
- if (array && array->cur_elem != first_elem_dir)
- {
- array->cur_elem = first_elem_dir;
- cur->sk_argument = array->elem_values[first_elem_dir];
- }
+ if (array)
+ _bt_array_set_low_or_high(rel, cur, array,
+ ScanDirectionIsForward(dir));
continue;
}
@@ -1080,14 +1650,22 @@ _bt_advance_array_keys(IndexScanDesc scan, BTReadPageState *pstate,
bool cur_elem_trig = (sktrig_required && ikey == sktrig);
/*
- * Binary search for closest match that's available from the array
+ * "Binary search" by checking if tupdatum/tupnull are within the
+ * range of the skip array
*/
- set_elem = _bt_binsrch_array_skey(&so->orderProcs[ikey],
- cur_elem_trig, dir,
- tupdatum, tupnull, array, cur,
- &result);
+ if (array->num_elems == -1)
+ _bt_binsrch_skiparray_skey(cur_elem_trig, dir,
+ tupdatum, tupnull, array, cur,
+ &result);
- Assert(set_elem >= 0 && set_elem < array->num_elems);
+ /*
+ * Binary search for the closest match from the SAOP array
+ */
+ else
+ set_elem = _bt_binsrch_array_skey(&so->orderProcs[ikey],
+ cur_elem_trig, dir,
+ tupdatum, tupnull, array, cur,
+ &result);
}
else
{
@@ -1163,11 +1741,21 @@ _bt_advance_array_keys(IndexScanDesc scan, BTReadPageState *pstate,
}
}
- /* Advance array keys, even when set_elem isn't an exact match */
- if (array && array->cur_elem != set_elem)
+ /* Advance array keys, even when we don't have an exact match */
+ if (array)
{
- array->cur_elem = set_elem;
- cur->sk_argument = array->elem_values[set_elem];
+ if (array->num_elems == -1)
+ {
+ /* Skip array's new element is tupdatum (or MINVAL/MAXVAL) */
+ _bt_skiparray_set_element(rel, cur, array, result,
+ tupdatum, tupnull);
+ }
+ else if (array->cur_elem != set_elem)
+ {
+ /* SAOP array's new element is set_elem datum */
+ array->cur_elem = set_elem;
+ cur->sk_argument = array->elem_values[set_elem];
+ }
}
}
@@ -1581,10 +2169,11 @@ _bt_verify_keys_with_arraykeys(IndexScanDesc scan)
if (array->scan_key != ikey)
return false;
- if (array->num_elems <= 0)
+ if (array->num_elems == 0 || array->num_elems < -1)
return false;
- if (cur->sk_argument != array->elem_values[array->cur_elem])
+ if (array->num_elems != -1 &&
+ cur->sk_argument != array->elem_values[array->cur_elem])
return false;
if (last_sk_attno > cur->sk_attno)
return false;
@@ -1914,6 +2503,20 @@ _bt_check_compare(IndexScanDesc scan, ScanDirection dir,
continue;
}
+ /*
+ * A skip array scan key uses one of several sentinel values. We just
+ * fall back on _bt_tuple_before_array_skeys when we see such a value.
+ */
+ if (key->sk_flags & (SK_BT_MINVAL | SK_BT_MAXVAL |
+ SK_BT_NEXT | SK_BT_PRIOR))
+ {
+ Assert(key->sk_flags & SK_SEARCHARRAY);
+ Assert(key->sk_flags & SK_BT_SKIP);
+
+ *continuescan = false;
+ return false;
+ }
+
/* row-comparison keys need special processing */
if (key->sk_flags & SK_ROW_HEADER)
{
@@ -1939,6 +2542,7 @@ _bt_check_compare(IndexScanDesc scan, ScanDirection dir,
else
{
Assert(key->sk_flags & SK_SEARCHNOTNULL);
+ Assert(!(key->sk_flags & SK_BT_SKIP));
if (!isNull)
continue; /* tuple satisfies this qual */
}
diff --git a/src/backend/access/nbtree/nbtvalidate.c b/src/backend/access/nbtree/nbtvalidate.c
index dd6f5a15c65..817ad358f0c 100644
--- a/src/backend/access/nbtree/nbtvalidate.c
+++ b/src/backend/access/nbtree/nbtvalidate.c
@@ -106,6 +106,10 @@ btvalidate(Oid opclassoid)
case BTOPTIONS_PROC:
ok = check_amoptsproc_signature(procform->amproc);
break;
+ case BTSKIPSUPPORT_PROC:
+ ok = check_amproc_signature(procform->amproc, VOIDOID, true,
+ 1, 1, INTERNALOID);
+ break;
default:
ereport(INFO,
(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
diff --git a/src/backend/commands/opclasscmds.c b/src/backend/commands/opclasscmds.c
index 8546366ee06..a6dd8eab518 100644
--- a/src/backend/commands/opclasscmds.c
+++ b/src/backend/commands/opclasscmds.c
@@ -1331,6 +1331,31 @@ assignProcTypes(OpFamilyMember *member, Oid amoid, Oid typeoid,
(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
errmsg("ordering equal image functions must not be cross-type")));
}
+ else if (member->number == BTSKIPSUPPORT_PROC)
+ {
+ if (procform->pronargs != 1 ||
+ procform->proargtypes.values[0] != INTERNALOID)
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
+ errmsg("btree skip support functions must accept type \"internal\"")));
+ if (procform->prorettype != VOIDOID)
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
+ errmsg("btree skip support functions must return void")));
+
+ /*
+ * pg_amproc functions are indexed by (lefttype, righttype), but a
+ * skip support function doesn't make sense in cross-type
+ * scenarios. The same opclass opcintype OID is always used for
+ * lefttype and righttype. Providing a cross-type routine isn't
+ * sensible. Reject cross-type ALTER OPERATOR FAMILY ... ADD
+ * FUNCTION 6 statements here.
+ */
+ if (member->lefttype != member->righttype)
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
+ errmsg("btree skip support functions must not be cross-type")));
+ }
}
else if (GetIndexAmRoutineByAmId(amoid, false)->amcanhash)
{
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 35e8c01aab9..4a233b63c32 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -99,6 +99,7 @@ OBJS = \
rowtypes.o \
ruleutils.o \
selfuncs.o \
+ skipsupport.o \
tid.o \
timestamp.o \
trigfuncs.o \
diff --git a/src/backend/utils/adt/date.c b/src/backend/utils/adt/date.c
index f279853deb8..4227ab1a72b 100644
--- a/src/backend/utils/adt/date.c
+++ b/src/backend/utils/adt/date.c
@@ -34,6 +34,7 @@
#include "utils/date.h"
#include "utils/datetime.h"
#include "utils/numeric.h"
+#include "utils/skipsupport.h"
#include "utils/sortsupport.h"
/*
@@ -462,6 +463,51 @@ date_sortsupport(PG_FUNCTION_ARGS)
PG_RETURN_VOID();
}
+static Datum
+date_decrement(Relation rel, Datum existing, bool *underflow)
+{
+ DateADT dexisting = DatumGetDateADT(existing);
+
+ if (dexisting == DATEVAL_NOBEGIN)
+ {
+ /* return value is undefined */
+ *underflow = true;
+ return (Datum) 0;
+ }
+
+ *underflow = false;
+ return DateADTGetDatum(dexisting - 1);
+}
+
+static Datum
+date_increment(Relation rel, Datum existing, bool *overflow)
+{
+ DateADT dexisting = DatumGetDateADT(existing);
+
+ if (dexisting == DATEVAL_NOEND)
+ {
+ /* return value is undefined */
+ *overflow = true;
+ return (Datum) 0;
+ }
+
+ *overflow = false;
+ return DateADTGetDatum(dexisting + 1);
+}
+
+Datum
+date_skipsupport(PG_FUNCTION_ARGS)
+{
+ SkipSupport sksup = (SkipSupport) PG_GETARG_POINTER(0);
+
+ sksup->decrement = date_decrement;
+ sksup->increment = date_increment;
+ sksup->low_elem = DateADTGetDatum(DATEVAL_NOBEGIN);
+ sksup->high_elem = DateADTGetDatum(DATEVAL_NOEND);
+
+ PG_RETURN_VOID();
+}
+
Datum
hashdate(PG_FUNCTION_ARGS)
{
diff --git a/src/backend/utils/adt/meson.build b/src/backend/utils/adt/meson.build
index f23cfad7182..244f48f4fd7 100644
--- a/src/backend/utils/adt/meson.build
+++ b/src/backend/utils/adt/meson.build
@@ -86,6 +86,7 @@ backend_sources += files(
'rowtypes.c',
'ruleutils.c',
'selfuncs.c',
+ 'skipsupport.c',
'tid.c',
'timestamp.c',
'trigfuncs.c',
diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c
index 462308807ef..021ea7517d7 100644
--- a/src/backend/utils/adt/selfuncs.c
+++ b/src/backend/utils/adt/selfuncs.c
@@ -193,6 +193,8 @@ static double convert_timevalue_to_scalar(Datum value, Oid typid,
bool *failure);
static void examine_simple_variable(PlannerInfo *root, Var *var,
VariableStatData *vardata);
+static void examine_indexcol_variable(PlannerInfo *root, IndexOptInfo *index,
+ int indexcol, VariableStatData *vardata);
static bool get_variable_range(PlannerInfo *root, VariableStatData *vardata,
Oid sortop, Oid collation,
Datum *min, Datum *max);
@@ -214,6 +216,8 @@ static bool get_actual_variable_endpoint(Relation heapRel,
MemoryContext outercontext,
Datum *endpointDatum);
static RelOptInfo *find_join_input_rel(PlannerInfo *root, Relids relids);
+static double btcost_correlation(IndexOptInfo *index,
+ VariableStatData *vardata);
/*
@@ -5944,6 +5948,92 @@ examine_simple_variable(PlannerInfo *root, Var *var,
}
/*
+ * examine_indexcol_variable
+ * Try to look up statistical data about an index column/expression.
+ * Fill in a VariableStatData struct to describe the column.
+ *
+ * Inputs:
+ * root: the planner info
+ * index: the index whose column we're interested in
+ * indexcol: 0-based index column number (subscripts index->indexkeys[])
+ *
+ * Outputs: *vardata is filled as follows:
+ * var: the input expression (with any binary relabeling stripped, if
+ * it is or contains a variable; but otherwise the type is preserved)
+ * rel: RelOptInfo for table relation containing variable.
+ * statsTuple: the pg_statistic entry for the variable, if one exists;
+ * otherwise NULL.
+ * freefunc: pointer to a function to release statsTuple with.
+ *
+ * Caller is responsible for doing ReleaseVariableStats() before exiting.
+ */
+static void
+examine_indexcol_variable(PlannerInfo *root, IndexOptInfo *index,
+ int indexcol, VariableStatData *vardata)
+{
+ AttrNumber colnum;
+ Oid relid;
+
+ if (index->indexkeys[indexcol] != 0)
+ {
+ /* Simple variable --- look to stats for the underlying table */
+ RangeTblEntry *rte = planner_rt_fetch(index->rel->relid, root);
+
+ Assert(rte->rtekind == RTE_RELATION);
+ relid = rte->relid;
+ Assert(relid != InvalidOid);
+ colnum = index->indexkeys[indexcol];
+ vardata->rel = index->rel;
+
+ if (get_relation_stats_hook &&
+ (*get_relation_stats_hook) (root, rte, colnum, vardata))
+ {
+ /*
+ * The hook took control of acquiring a stats tuple. If it did
+ * supply a tuple, it'd better have supplied a freefunc.
+ */
+ if (HeapTupleIsValid(vardata->statsTuple) &&
+ !vardata->freefunc)
+ elog(ERROR, "no function provided to release variable stats with");
+ }
+ else
+ {
+ vardata->statsTuple = SearchSysCache3(STATRELATTINH,
+ ObjectIdGetDatum(relid),
+ Int16GetDatum(colnum),
+ BoolGetDatum(rte->inh));
+ vardata->freefunc = ReleaseSysCache;
+ }
+ }
+ else
+ {
+ /* Expression --- maybe there are stats for the index itself */
+ relid = index->indexoid;
+ colnum = indexcol + 1;
+
+ if (get_index_stats_hook &&
+ (*get_index_stats_hook) (root, relid, colnum, vardata))
+ {
+ /*
+ * The hook took control of acquiring a stats tuple. If it did
+ * supply a tuple, it'd better have supplied a freefunc.
+ */
+ if (HeapTupleIsValid(vardata->statsTuple) &&
+ !vardata->freefunc)
+ elog(ERROR, "no function provided to release variable stats with");
+ }
+ else
+ {
+ vardata->statsTuple = SearchSysCache3(STATRELATTINH,
+ ObjectIdGetDatum(relid),
+ Int16GetDatum(colnum),
+ BoolGetDatum(false));
+ vardata->freefunc = ReleaseSysCache;
+ }
+ }
+}
+
+/*
* Check whether it is permitted to call func_oid passing some of the
* pg_statistic data in vardata. We allow this either if the user has SELECT
* privileges on the table or column underlying the pg_statistic data or if
@@ -7007,6 +7097,53 @@ add_predicate_to_index_quals(IndexOptInfo *index, List *indexQuals)
return list_concat(predExtraQuals, indexQuals);
}
+/*
+ * Estimate correlation of btree index's first column.
+ *
+ * If we can get an estimate of the first column's ordering correlation C
+ * from pg_statistic, estimate the index correlation as C for a single-column
+ * index, or C * 0.75 for multiple columns. The idea here is that multiple
+ * columns dilute the importance of the first column's ordering, but don't
+ * negate it entirely.
+ *
+ * We already filled in the stats tuple for *vardata when called.
+ */
+static double
+btcost_correlation(IndexOptInfo *index, VariableStatData *vardata)
+{
+ Oid sortop;
+ AttStatsSlot sslot;
+ double indexCorrelation = 0;
+
+ Assert(HeapTupleIsValid(vardata->statsTuple));
+
+ sortop = get_opfamily_member(index->opfamily[0],
+ index->opcintype[0],
+ index->opcintype[0],
+ BTLessStrategyNumber);
+ if (OidIsValid(sortop) &&
+ get_attstatsslot(&sslot, vardata->statsTuple,
+ STATISTIC_KIND_CORRELATION, sortop,
+ ATTSTATSSLOT_NUMBERS))
+ {
+ double varCorrelation;
+
+ Assert(sslot.nnumbers == 1);
+ varCorrelation = sslot.numbers[0];
+
+ if (index->reverse_sort[0])
+ varCorrelation = -varCorrelation;
+
+ if (index->nkeycolumns > 1)
+ indexCorrelation = varCorrelation * 0.75;
+ else
+ indexCorrelation = varCorrelation;
+
+ free_attstatsslot(&sslot);
+ }
+
+ return indexCorrelation;
+}
void
btcostestimate(PlannerInfo *root, IndexPath *path, double loop_count,
@@ -7016,17 +7153,19 @@ btcostestimate(PlannerInfo *root, IndexPath *path, double loop_count,
{
IndexOptInfo *index = path->indexinfo;
GenericCosts costs = {0};
- Oid relid;
- AttrNumber colnum;
VariableStatData vardata = {0};
double numIndexTuples;
Cost descentCost;
List *indexBoundQuals;
+ List *indexSkipQuals;
int indexcol;
bool eqQualHere;
- bool found_saop;
+ bool found_row_compare;
+ bool found_array;
bool found_is_null_op;
+ bool have_correlation = false;
double num_sa_scans;
+ double correlation = 0.0;
ListCell *lc;
/*
@@ -7037,19 +7176,24 @@ btcostestimate(PlannerInfo *root, IndexPath *path, double loop_count,
* it's OK to count them in indexSelectivity, but they should not count
* for estimating numIndexTuples. So we must examine the given indexquals
* to find out which ones count as boundary quals. We rely on the
- * knowledge that they are given in index column order.
+ * knowledge that they are given in index column order. Note that nbtree
+ * preprocessing can add skip arrays that act as leading '=' quals in the
+ * absence of ordinary input '=' quals, so in practice _most_ input quals
+ * are able to act as index bound quals (which we take into account here).
*
* For a RowCompareExpr, we consider only the first column, just as
* rowcomparesel() does.
*
- * If there's a ScalarArrayOpExpr in the quals, we'll actually perform up
- * to N index descents (not just one), but the ScalarArrayOpExpr's
+ * If there's a SAOP or skip array in the quals, we'll actually perform up
+ * to N index descents (not just one), but the underlying array key's
* operator can be considered to act the same as it normally does.
*/
indexBoundQuals = NIL;
+ indexSkipQuals = NIL;
indexcol = 0;
eqQualHere = false;
- found_saop = false;
+ found_row_compare = false;
+ found_array = false;
found_is_null_op = false;
num_sa_scans = 1;
foreach(lc, path->indexclauses)
@@ -7057,17 +7201,203 @@ btcostestimate(PlannerInfo *root, IndexPath *path, double loop_count,
IndexClause *iclause = lfirst_node(IndexClause, lc);
ListCell *lc2;
- if (indexcol != iclause->indexcol)
+ if (indexcol < iclause->indexcol)
{
- /* Beginning of a new column's quals */
- if (!eqQualHere)
- break; /* done if no '=' qual for indexcol */
+ double num_sa_scans_prev_cols = num_sa_scans;
+
+ /*
+ * Beginning of a new column's quals.
+ *
+ * Skip scans use skip arrays, which are ScalarArrayOp style
+ * arrays that generate their elements procedurally and on demand.
+ * Given a multi-column index on "(a, b)", and an SQL WHERE clause
+ * "WHERE b = 42", a skip scan will effectively use an indexqual
+ * "WHERE a = ANY('{every col a value}') AND b = 42". (Obviously,
+ * the array on "a" must also return "IS NULL" matches, since our
+ * WHERE clause used no strict operator on "a").
+ *
+ * Here we consider how nbtree will backfill skip arrays for any
+ * index columns that lacked an '=' qual. This maintains our
+ * num_sa_scans estimate, and determines if this new column (the
+ * "iclause->indexcol" column, not the prior "indexcol" column)
+ * can have its RestrictInfos/quals added to indexBoundQuals.
+ *
+ * We'll need to handle columns that have inequality quals, where
+ * the skip array generates values from a range constrained by the
+ * quals (not every possible value). We've been maintaining
+ * indexSkipQuals to help with this; it will now contain all of
+ * the prior column's quals (that is, indexcol's quals) when they
+ * might be used for this.
+ */
+ if (found_row_compare)
+ {
+ /*
+ * Skip arrays can't be added after a RowCompare input qual
+ * due to limitations in nbtree
+ */
+ break;
+ }
+ if (eqQualHere)
+ {
+ /*
+ * Don't need to add a skip array for an indexcol that already
+ * has an '=' qual/equality constraint
+ */
+ indexcol++;
+ indexSkipQuals = NIL;
+ }
eqQualHere = false;
- indexcol++;
+
+ while (indexcol < iclause->indexcol)
+ {
+ double ndistinct;
+ bool isdefault = true;
+
+ found_array = true;
+
+ /*
+ * A skipped attribute's ndistinct forms the basis of our
+ * estimate of the total number of "array elements" used by
+ * its skip array at runtime. Look that up first.
+ */
+ examine_indexcol_variable(root, index, indexcol, &vardata);
+ ndistinct = get_variable_numdistinct(&vardata, &isdefault);
+
+ if (indexcol == 0)
+ {
+ /*
+ * Get an estimate of the leading column's correlation in
+ * passing (avoids rereading variable stats below)
+ */
+ if (HeapTupleIsValid(vardata.statsTuple))
+ correlation = btcost_correlation(index, &vardata);
+ have_correlation = true;
+ }
+
+ ReleaseVariableStats(vardata);
+
+ /*
+ * If ndistinct is a default estimate, conservatively assume
+ * that no skipping will happen at runtime
+ */
+ if (isdefault)
+ {
+ num_sa_scans = num_sa_scans_prev_cols;
+ break; /* done building indexBoundQuals */
+ }
+
+ /*
+ * Apply indexcol's indexSkipQuals selectivity to ndistinct
+ */
+ if (indexSkipQuals != NIL)
+ {
+ List *partialSkipQuals;
+ Selectivity ndistinctfrac;
+
+ /*
+ * If the index is partial, AND the index predicate with
+ * the index-bound quals to produce a more accurate idea
+ * of the number of distinct values for prior indexcol
+ */
+ partialSkipQuals = add_predicate_to_index_quals(index,
+ indexSkipQuals);
+
+ ndistinctfrac = clauselist_selectivity(root, partialSkipQuals,
+ index->rel->relid,
+ JOIN_INNER,
+ NULL);
+
+ /*
+ * If ndistinctfrac is selective (on its own), the scan is
+ * unlikely to benefit from repositioning itself using
+ * later quals. Do not allow iclause->indexcol's quals to
+ * be added to indexBoundQuals (it would increase descent
+ * costs, without lowering numIndexTuples costs by much).
+ */
+ if (ndistinctfrac < DEFAULT_RANGE_INEQ_SEL)
+ {
+ num_sa_scans = num_sa_scans_prev_cols;
+ break; /* done building indexBoundQuals */
+ }
+
+ /* Adjust ndistinct downward */
+ ndistinct = rint(ndistinct * ndistinctfrac);
+ ndistinct = Max(ndistinct, 1);
+ }
+
+ /*
+ * When there's no inequality quals, account for the need to
+ * find an initial value by counting -inf/+inf as a value.
+ *
+ * We don't charge anything extra for possible next/prior key
+ * index probes, which are sometimes used to find the next
+ * valid skip array element (ahead of using the located
+ * element value to relocate the scan to the next position
+ * that might contain matching tuples). It seems hard to do
+ * better here. Use of the skip support infrastructure often
+ * avoids most next/prior key probes. But even when it can't,
+ * there's a decent chance that most individual next/prior key
+ * probes will locate a leaf page whose key space overlaps all
+ * of the scan's keys (even the lower-order keys) -- which
+ * also avoids the need for a separate, extra index descent.
+ * Note also that these probes are much cheaper than non-probe
+ * primitive index scans: they're reliably very selective.
+ */
+ if (indexSkipQuals == NIL)
+ ndistinct += 1;
+
+ /*
+ * Update num_sa_scans estimate by multiplying by ndistinct.
+ *
+ * We make the pessimistic assumption that there is no
+ * naturally occurring cross-column correlation. This is
+ * often wrong, but it seems best to err on the side of not
+ * expecting skipping to be helpful...
+ */
+ num_sa_scans *= ndistinct;
+
+ /*
+ * ...but back out of adding this latest group of 1 or more
+ * skip arrays when num_sa_scans exceeds the total number of
+ * index pages (revert to num_sa_scans from before indexcol).
+ * This causes a sharp discontinuity in cost (as a function of
+ * the indexcol's ndistinct), but that is representative of
+ * actual runtime costs.
+ *
+ * Note that skipping is helpful when each primitive index
+ * scan only manages to skip over 1 or 2 irrelevant leaf pages
+ * on average. Skip arrays bring savings in CPU costs due to
+ * the scan not needing to evaluate indexquals against every
+ * tuple, which can greatly exceed any savings in I/O costs.
+ * This test is a test of whether num_sa_scans implies that
+ * we're past the point where the ability to skip ceases to
+ * lower the scan's costs (even qual evaluation CPU costs).
+ */
+ if (index->pages < num_sa_scans)
+ {
+ num_sa_scans = num_sa_scans_prev_cols;
+ break; /* done building indexBoundQuals */
+ }
+
+ indexcol++;
+ indexSkipQuals = NIL;
+ }
+
+ /*
+ * Finished considering the need to add skip arrays to bridge an
+ * initial eqQualHere gap between the old and new index columns
+ * (or there was no initial eqQualHere gap in the first place).
+ *
+ * If an initial gap could not be bridged, then new column's quals
+ * (i.e. iclause->indexcol's quals) won't go into indexBoundQuals,
+ * and so won't affect our final numIndexTuples estimate.
+ */
if (indexcol != iclause->indexcol)
- break; /* no quals at all for indexcol */
+ break; /* done building indexBoundQuals */
}
+ Assert(indexcol == iclause->indexcol);
+
/* Examine each indexqual associated with this index clause */
foreach(lc2, iclause->indexquals)
{
@@ -7087,6 +7417,7 @@ btcostestimate(PlannerInfo *root, IndexPath *path, double loop_count,
RowCompareExpr *rc = (RowCompareExpr *) clause;
clause_op = linitial_oid(rc->opnos);
+ found_row_compare = true;
}
else if (IsA(clause, ScalarArrayOpExpr))
{
@@ -7095,7 +7426,7 @@ btcostestimate(PlannerInfo *root, IndexPath *path, double loop_count,
double alength = estimate_array_length(root, other_operand);
clause_op = saop->opno;
- found_saop = true;
+ found_array = true;
/* estimate SA descents by indexBoundQuals only */
if (alength > 1)
num_sa_scans *= alength;
@@ -7107,7 +7438,7 @@ btcostestimate(PlannerInfo *root, IndexPath *path, double loop_count,
if (nt->nulltesttype == IS_NULL)
{
found_is_null_op = true;
- /* IS NULL is like = for selectivity purposes */
+ /* IS NULL is like = for selectivity/skip scan purposes */
eqQualHere = true;
}
}
@@ -7126,19 +7457,28 @@ btcostestimate(PlannerInfo *root, IndexPath *path, double loop_count,
}
indexBoundQuals = lappend(indexBoundQuals, rinfo);
+
+ /*
+ * We apply inequality selectivities to estimate index descent
+ * costs with scans that use skip arrays. Save this indexcol's
+ * RestrictInfos if it looks like they'll be needed for that.
+ */
+ if (!eqQualHere && !found_row_compare &&
+ indexcol < index->nkeycolumns - 1)
+ indexSkipQuals = lappend(indexSkipQuals, rinfo);
}
}
/*
* If index is unique and we found an '=' clause for each column, we can
* just assume numIndexTuples = 1 and skip the expensive
- * clauselist_selectivity calculations. However, a ScalarArrayOp or
- * NullTest invalidates that theory, even though it sets eqQualHere.
+ * clauselist_selectivity calculations. However, an array or NullTest
+ * always invalidates that theory (even when eqQualHere has been set).
*/
if (index->unique &&
indexcol == index->nkeycolumns - 1 &&
eqQualHere &&
- !found_saop &&
+ !found_array &&
!found_is_null_op)
numIndexTuples = 1.0;
else
@@ -7160,7 +7500,7 @@ btcostestimate(PlannerInfo *root, IndexPath *path, double loop_count,
numIndexTuples = btreeSelectivity * index->rel->tuples;
/*
- * btree automatically combines individual ScalarArrayOpExpr primitive
+ * btree automatically combines individual array element primitive
* index scans whenever the tuples covered by the next set of array
* keys are close to tuples covered by the current set. That puts a
* natural ceiling on the worst case number of descents -- there
@@ -7178,16 +7518,18 @@ btcostestimate(PlannerInfo *root, IndexPath *path, double loop_count,
* of leaf pages (we make it 1/3 the total number of pages instead) to
* give the btree code credit for its ability to continue on the leaf
* level with low selectivity scans.
+ *
+ * Note: num_sa_scans includes both ScalarArrayOp array elements and
+ * skip array elements whose qual affects our numIndexTuples estimate.
*/
num_sa_scans = Min(num_sa_scans, ceil(index->pages * 0.3333333));
num_sa_scans = Max(num_sa_scans, 1);
/*
- * As in genericcostestimate(), we have to adjust for any
- * ScalarArrayOpExpr quals included in indexBoundQuals, and then round
- * to integer.
+ * As in genericcostestimate(), we have to adjust for any array quals
+ * included in indexBoundQuals, and then round to integer.
*
- * It is tempting to make genericcostestimate behave as if SAOP
+ * It is tempting to make genericcostestimate behave as if array
* clauses work in almost the same way as scalar operators during
* btree scans, making the top-level scan look like a continuous scan
* (as opposed to num_sa_scans-many primitive index scans). After
@@ -7220,7 +7562,7 @@ btcostestimate(PlannerInfo *root, IndexPath *path, double loop_count,
* comparisons to descend a btree of N leaf tuples. We charge one
* cpu_operator_cost per comparison.
*
- * If there are ScalarArrayOpExprs, charge this once per estimated SA
+ * If there are SAOP or skip array keys, charge this once per estimated
* index descent. The ones after the first one are not startup cost so
* far as the overall plan goes, so just add them to "total" cost.
*/
@@ -7240,110 +7582,25 @@ btcostestimate(PlannerInfo *root, IndexPath *path, double loop_count,
* cost is somewhat arbitrarily set at 50x cpu_operator_cost per page
* touched. The number of such pages is btree tree height plus one (ie,
* we charge for the leaf page too). As above, charge once per estimated
- * SA index descent.
+ * SAOP/skip array descent.
*/
descentCost = (index->tree_height + 1) * DEFAULT_PAGE_CPU_MULTIPLIER * cpu_operator_cost;
costs.indexStartupCost += descentCost;
costs.indexTotalCost += costs.num_sa_scans * descentCost;
- /*
- * If we can get an estimate of the first column's ordering correlation C
- * from pg_statistic, estimate the index correlation as C for a
- * single-column index, or C * 0.75 for multiple columns. (The idea here
- * is that multiple columns dilute the importance of the first column's
- * ordering, but don't negate it entirely. Before 8.0 we divided the
- * correlation by the number of columns, but that seems too strong.)
- */
- if (index->indexkeys[0] != 0)
+ if (!have_correlation)
{
- /* Simple variable --- look to stats for the underlying table */
- RangeTblEntry *rte = planner_rt_fetch(index->rel->relid, root);
-
- Assert(rte->rtekind == RTE_RELATION);
- relid = rte->relid;
- Assert(relid != InvalidOid);
- colnum = index->indexkeys[0];
-
- if (get_relation_stats_hook &&
- (*get_relation_stats_hook) (root, rte, colnum, &vardata))
- {
- /*
- * The hook took control of acquiring a stats tuple. If it did
- * supply a tuple, it'd better have supplied a freefunc.
- */
- if (HeapTupleIsValid(vardata.statsTuple) &&
- !vardata.freefunc)
- elog(ERROR, "no function provided to release variable stats with");
- }
- else
- {
- vardata.statsTuple = SearchSysCache3(STATRELATTINH,
- ObjectIdGetDatum(relid),
- Int16GetDatum(colnum),
- BoolGetDatum(rte->inh));
- vardata.freefunc = ReleaseSysCache;
- }
+ examine_indexcol_variable(root, index, 0, &vardata);
+ if (HeapTupleIsValid(vardata.statsTuple))
+ costs.indexCorrelation = btcost_correlation(index, &vardata);
+ ReleaseVariableStats(vardata);
}
else
{
- /* Expression --- maybe there are stats for the index itself */
- relid = index->indexoid;
- colnum = 1;
-
- if (get_index_stats_hook &&
- (*get_index_stats_hook) (root, relid, colnum, &vardata))
- {
- /*
- * The hook took control of acquiring a stats tuple. If it did
- * supply a tuple, it'd better have supplied a freefunc.
- */
- if (HeapTupleIsValid(vardata.statsTuple) &&
- !vardata.freefunc)
- elog(ERROR, "no function provided to release variable stats with");
- }
- else
- {
- vardata.statsTuple = SearchSysCache3(STATRELATTINH,
- ObjectIdGetDatum(relid),
- Int16GetDatum(colnum),
- BoolGetDatum(false));
- vardata.freefunc = ReleaseSysCache;
- }
+ /* btcost_correlation already called earlier on */
+ costs.indexCorrelation = correlation;
}
- if (HeapTupleIsValid(vardata.statsTuple))
- {
- Oid sortop;
- AttStatsSlot sslot;
-
- sortop = get_opfamily_member(index->opfamily[0],
- index->opcintype[0],
- index->opcintype[0],
- BTLessStrategyNumber);
- if (OidIsValid(sortop) &&
- get_attstatsslot(&sslot, vardata.statsTuple,
- STATISTIC_KIND_CORRELATION, sortop,
- ATTSTATSSLOT_NUMBERS))
- {
- double varCorrelation;
-
- Assert(sslot.nnumbers == 1);
- varCorrelation = sslot.numbers[0];
-
- if (index->reverse_sort[0])
- varCorrelation = -varCorrelation;
-
- if (index->nkeycolumns > 1)
- costs.indexCorrelation = varCorrelation * 0.75;
- else
- costs.indexCorrelation = varCorrelation;
-
- free_attstatsslot(&sslot);
- }
- }
-
- ReleaseVariableStats(vardata);
-
*indexStartupCost = costs.indexStartupCost;
*indexTotalCost = costs.indexTotalCost;
*indexSelectivity = costs.indexSelectivity;
diff --git a/src/backend/utils/adt/skipsupport.c b/src/backend/utils/adt/skipsupport.c
new file mode 100644
index 00000000000..2bd35d2d272
--- /dev/null
+++ b/src/backend/utils/adt/skipsupport.c
@@ -0,0 +1,61 @@
+/*-------------------------------------------------------------------------
+ *
+ * skipsupport.c
+ * Support routines for B-Tree skip scan.
+ *
+ *
+ * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * IDENTIFICATION
+ * src/backend/utils/adt/skipsupport.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "postgres.h"
+
+#include "access/nbtree.h"
+#include "utils/lsyscache.h"
+#include "utils/skipsupport.h"
+
+/*
+ * Fill in SkipSupport given an operator class (opfamily + opcintype).
+ *
+ * On success, returns skip support struct, allocating in caller's memory
+ * context. Otherwise returns NULL, indicating that operator class has no
+ * skip support function.
+ */
+SkipSupport
+PrepareSkipSupportFromOpclass(Oid opfamily, Oid opcintype, bool reverse)
+{
+ Oid skipSupportFunction;
+ SkipSupport sksup;
+
+ /* Look for a skip support function */
+ skipSupportFunction = get_opfamily_proc(opfamily, opcintype, opcintype,
+ BTSKIPSUPPORT_PROC);
+ if (!OidIsValid(skipSupportFunction))
+ return NULL;
+
+ sksup = palloc(sizeof(SkipSupportData));
+ OidFunctionCall1(skipSupportFunction, PointerGetDatum(sksup));
+
+ if (reverse)
+ {
+ /*
+ * DESC/reverse case: swap low_elem with high_elem, and swap decrement
+ * with increment
+ */
+ Datum low_elem = sksup->low_elem;
+ SkipSupportIncDec decrement = sksup->decrement;
+
+ sksup->low_elem = sksup->high_elem;
+ sksup->decrement = sksup->increment;
+
+ sksup->high_elem = low_elem;
+ sksup->increment = decrement;
+ }
+
+ return sksup;
+}
diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 9682f9dbdca..347089b7626 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -37,6 +37,7 @@
#include "utils/datetime.h"
#include "utils/float.h"
#include "utils/numeric.h"
+#include "utils/skipsupport.h"
#include "utils/sortsupport.h"
/*
@@ -2304,6 +2305,53 @@ timestamp_sortsupport(PG_FUNCTION_ARGS)
PG_RETURN_VOID();
}
+/* note: this is used for timestamptz also */
+static Datum
+timestamp_decrement(Relation rel, Datum existing, bool *underflow)
+{
+ Timestamp texisting = DatumGetTimestamp(existing);
+
+ if (texisting == PG_INT64_MIN)
+ {
+ /* return value is undefined */
+ *underflow = true;
+ return (Datum) 0;
+ }
+
+ *underflow = false;
+ return TimestampGetDatum(texisting - 1);
+}
+
+/* note: this is used for timestamptz also */
+static Datum
+timestamp_increment(Relation rel, Datum existing, bool *overflow)
+{
+ Timestamp texisting = DatumGetTimestamp(existing);
+
+ if (texisting == PG_INT64_MAX)
+ {
+ /* return value is undefined */
+ *overflow = true;
+ return (Datum) 0;
+ }
+
+ *overflow = false;
+ return TimestampGetDatum(texisting + 1);
+}
+
+Datum
+timestamp_skipsupport(PG_FUNCTION_ARGS)
+{
+ SkipSupport sksup = (SkipSupport) PG_GETARG_POINTER(0);
+
+ sksup->decrement = timestamp_decrement;
+ sksup->increment = timestamp_increment;
+ sksup->low_elem = TimestampGetDatum(PG_INT64_MIN);
+ sksup->high_elem = TimestampGetDatum(PG_INT64_MAX);
+
+ PG_RETURN_VOID();
+}
+
Datum
timestamp_hash(PG_FUNCTION_ARGS)
{
diff --git a/src/backend/utils/adt/uuid.c b/src/backend/utils/adt/uuid.c
index be0f0f9f1ce..bce7309c183 100644
--- a/src/backend/utils/adt/uuid.c
+++ b/src/backend/utils/adt/uuid.c
@@ -13,6 +13,7 @@
#include "postgres.h"
+#include <limits.h>
#include <time.h> /* for clock_gettime() */
#include "common/hashfn.h"
@@ -21,6 +22,7 @@
#include "port/pg_bswap.h"
#include "utils/fmgrprotos.h"
#include "utils/guc.h"
+#include "utils/skipsupport.h"
#include "utils/sortsupport.h"
#include "utils/timestamp.h"
#include "utils/uuid.h"
@@ -418,6 +420,74 @@ uuid_abbrev_convert(Datum original, SortSupport ssup)
return res;
}
+static Datum
+uuid_decrement(Relation rel, Datum existing, bool *underflow)
+{
+ pg_uuid_t *uuid;
+
+ uuid = (pg_uuid_t *) palloc(UUID_LEN);
+ memcpy(uuid, DatumGetUUIDP(existing), UUID_LEN);
+ for (int i = UUID_LEN - 1; i >= 0; i--)
+ {
+ if (uuid->data[i] > 0)
+ {
+ uuid->data[i]--;
+ *underflow = false;
+ return UUIDPGetDatum(uuid);
+ }
+ uuid->data[i] = UCHAR_MAX;
+ }
+
+ pfree(uuid); /* cannot leak memory */
+
+ /* return value is undefined */
+ *underflow = true;
+ return (Datum) 0;
+}
+
+static Datum
+uuid_increment(Relation rel, Datum existing, bool *overflow)
+{
+ pg_uuid_t *uuid;
+
+ uuid = (pg_uuid_t *) palloc(UUID_LEN);
+ memcpy(uuid, DatumGetUUIDP(existing), UUID_LEN);
+ for (int i = UUID_LEN - 1; i >= 0; i--)
+ {
+ if (uuid->data[i] < UCHAR_MAX)
+ {
+ uuid->data[i]++;
+ *overflow = false;
+ return UUIDPGetDatum(uuid);
+ }
+ uuid->data[i] = 0;
+ }
+
+ pfree(uuid); /* cannot leak memory */
+
+ /* return value is undefined */
+ *overflow = true;
+ return (Datum) 0;
+}
+
+Datum
+uuid_skipsupport(PG_FUNCTION_ARGS)
+{
+ SkipSupport sksup = (SkipSupport) PG_GETARG_POINTER(0);
+ pg_uuid_t *uuid_min = palloc(UUID_LEN);
+ pg_uuid_t *uuid_max = palloc(UUID_LEN);
+
+ memset(uuid_min->data, 0x00, UUID_LEN);
+ memset(uuid_max->data, 0xFF, UUID_LEN);
+
+ sksup->decrement = uuid_decrement;
+ sksup->increment = uuid_increment;
+ sksup->low_elem = UUIDPGetDatum(uuid_min);
+ sksup->high_elem = UUIDPGetDatum(uuid_max);
+
+ PG_RETURN_VOID();
+}
+
/* hash index support */
Datum
uuid_hash(PG_FUNCTION_ARGS)
diff --git a/src/include/access/amapi.h b/src/include/access/amapi.h
index c4a0737731f..52916bab7a3 100644
--- a/src/include/access/amapi.h
+++ b/src/include/access/amapi.h
@@ -214,7 +214,8 @@ typedef void (*amrestrpos_function) (IndexScanDesc scan);
*/
/* estimate size of parallel scan descriptor */
-typedef Size (*amestimateparallelscan_function) (int nkeys, int norderbys);
+typedef Size (*amestimateparallelscan_function) (Relation indexRelation,
+ int nkeys, int norderbys);
/* prepare for parallel index scan */
typedef void (*aminitparallelscan_function) (void *target);
diff --git a/src/include/access/nbtree.h b/src/include/access/nbtree.h
index faabcb78e7b..9d9b76d5b48 100644
--- a/src/include/access/nbtree.h
+++ b/src/include/access/nbtree.h
@@ -24,6 +24,7 @@
#include "lib/stringinfo.h"
#include "storage/bufmgr.h"
#include "storage/shm_toc.h"
+#include "utils/skipsupport.h"
/* There's room for a 16-bit vacuum cycle ID in BTPageOpaqueData */
typedef uint16 BTCycleId;
@@ -707,6 +708,10 @@ BTreeTupleGetMaxHeapTID(IndexTuple itup)
* (BTOPTIONS_PROC). These procedures define a set of user-visible
* parameters that can be used to control operator class behavior. None of
* the built-in B-Tree operator classes currently register an "options" proc.
+ *
+ * To facilitate more efficient B-Tree skip scans, an operator class may
+ * choose to offer a sixth amproc procedure (BTSKIPSUPPORT_PROC). For full
+ * details, see src/include/utils/skipsupport.h.
*/
#define BTORDER_PROC 1
@@ -714,7 +719,8 @@ BTreeTupleGetMaxHeapTID(IndexTuple itup)
#define BTINRANGE_PROC 3
#define BTEQUALIMAGE_PROC 4
#define BTOPTIONS_PROC 5
-#define BTNProcs 5
+#define BTSKIPSUPPORT_PROC 6
+#define BTNProcs 6
/*
* We need to be able to tell the difference between read and write
@@ -1027,10 +1033,21 @@ typedef BTScanPosData *BTScanPos;
/* We need one of these for each equality-type SK_SEARCHARRAY scan key */
typedef struct BTArrayKeyInfo
{
+ /* fields set for both kinds of array (SAOP arrays and skip arrays) */
int scan_key; /* index of associated key in keyData */
- int cur_elem; /* index of current element in elem_values */
- int num_elems; /* number of elems in current array value */
+ int num_elems; /* number of elems (-1 means skip array) */
+
+ /* fields set for ScalarArrayOpExpr arrays only */
Datum *elem_values; /* array of num_elems Datums */
+ int cur_elem; /* index of current element in elem_values */
+
+ /* fields set for skip arrays only */
+ int16 attlen; /* attr's length, in bytes */
+ bool attbyval; /* attr's FormData_pg_attribute.attbyval */
+ bool null_elem; /* NULL is lowest/highest element? */
+ SkipSupport sksup; /* skip support (NULL if opclass lacks it) */
+ ScanKey low_compare; /* array's > or >= lower bound */
+ ScanKey high_compare; /* array's < or <= upper bound */
} BTArrayKeyInfo;
typedef struct BTScanOpaqueData
@@ -1119,6 +1136,15 @@ typedef struct BTReadPageState
*/
#define SK_BT_REQFWD 0x00010000 /* required to continue forward scan */
#define SK_BT_REQBKWD 0x00020000 /* required to continue backward scan */
+#define SK_BT_SKIP 0x00040000 /* skip array on column without input = */
+
+/* SK_BT_SKIP-only flags (set and unset by array advancement) */
+#define SK_BT_MINVAL 0x00080000 /* invalid sk_argument, use low_compare */
+#define SK_BT_MAXVAL 0x00100000 /* invalid sk_argument, use high_compare */
+#define SK_BT_NEXT 0x00200000 /* positions the scan > sk_argument */
+#define SK_BT_PRIOR 0x00400000 /* positions the scan < sk_argument */
+
+/* Remaps pg_index flag bits to uppermost SK_BT_* byte */
#define SK_BT_INDOPTION_SHIFT 24 /* must clear the above bits */
#define SK_BT_DESC (INDOPTION_DESC << SK_BT_INDOPTION_SHIFT)
#define SK_BT_NULLS_FIRST (INDOPTION_NULLS_FIRST << SK_BT_INDOPTION_SHIFT)
@@ -1165,7 +1191,7 @@ extern bool btinsert(Relation rel, Datum *values, bool *isnull,
bool indexUnchanged,
struct IndexInfo *indexInfo);
extern IndexScanDesc btbeginscan(Relation rel, int nkeys, int norderbys);
-extern Size btestimateparallelscan(int nkeys, int norderbys);
+extern Size btestimateparallelscan(Relation rel, int nkeys, int norderbys);
extern void btinitparallelscan(void *target);
extern bool btgettuple(IndexScanDesc scan, ScanDirection dir);
extern int64 btgetbitmap(IndexScanDesc scan, TIDBitmap *tbm);
diff --git a/src/include/catalog/catversion.h b/src/include/catalog/catversion.h
index 950fda777fb..208936962ef 100644
--- a/src/include/catalog/catversion.h
+++ b/src/include/catalog/catversion.h
@@ -57,6 +57,6 @@
*/
/* yyyymmddN */
-#define CATALOG_VERSION_NO 202504031
+#define CATALOG_VERSION_NO 202504041
#endif
diff --git a/src/include/catalog/pg_amproc.dat b/src/include/catalog/pg_amproc.dat
index 41056171059..92505148998 100644
--- a/src/include/catalog/pg_amproc.dat
+++ b/src/include/catalog/pg_amproc.dat
@@ -22,6 +22,8 @@
{ amprocfamily => 'btree/bool_ops', amproclefttype => 'bool',
amprocrighttype => 'bool', amprocnum => '1', amproc => 'btboolcmp' },
{ amprocfamily => 'btree/bool_ops', amproclefttype => 'bool',
+ amprocrighttype => 'bool', amprocnum => '6', amproc => 'btboolskipsupport' },
+{ amprocfamily => 'btree/bool_ops', amproclefttype => 'bool',
amprocrighttype => 'bool', amprocnum => '4', amproc => 'btequalimage' },
{ amprocfamily => 'btree/bpchar_ops', amproclefttype => 'bpchar',
amprocrighttype => 'bpchar', amprocnum => '1', amproc => 'bpcharcmp' },
@@ -41,6 +43,8 @@
amprocrighttype => 'char', amprocnum => '1', amproc => 'btcharcmp' },
{ amprocfamily => 'btree/char_ops', amproclefttype => 'char',
amprocrighttype => 'char', amprocnum => '4', amproc => 'btequalimage' },
+{ amprocfamily => 'btree/char_ops', amproclefttype => 'char',
+ amprocrighttype => 'char', amprocnum => '6', amproc => 'btcharskipsupport' },
{ amprocfamily => 'btree/datetime_ops', amproclefttype => 'date',
amprocrighttype => 'date', amprocnum => '1', amproc => 'date_cmp' },
{ amprocfamily => 'btree/datetime_ops', amproclefttype => 'date',
@@ -48,6 +52,8 @@
{ amprocfamily => 'btree/datetime_ops', amproclefttype => 'date',
amprocrighttype => 'date', amprocnum => '4', amproc => 'btequalimage' },
{ amprocfamily => 'btree/datetime_ops', amproclefttype => 'date',
+ amprocrighttype => 'date', amprocnum => '6', amproc => 'date_skipsupport' },
+{ amprocfamily => 'btree/datetime_ops', amproclefttype => 'date',
amprocrighttype => 'timestamp', amprocnum => '1',
amproc => 'date_cmp_timestamp' },
{ amprocfamily => 'btree/datetime_ops', amproclefttype => 'date',
@@ -61,6 +67,9 @@
{ amprocfamily => 'btree/datetime_ops', amproclefttype => 'timestamp',
amprocrighttype => 'timestamp', amprocnum => '4', amproc => 'btequalimage' },
{ amprocfamily => 'btree/datetime_ops', amproclefttype => 'timestamp',
+ amprocrighttype => 'timestamp', amprocnum => '6',
+ amproc => 'timestamp_skipsupport' },
+{ amprocfamily => 'btree/datetime_ops', amproclefttype => 'timestamp',
amprocrighttype => 'date', amprocnum => '1', amproc => 'timestamp_cmp_date' },
{ amprocfamily => 'btree/datetime_ops', amproclefttype => 'timestamp',
amprocrighttype => 'timestamptz', amprocnum => '1',
@@ -75,6 +84,9 @@
amprocrighttype => 'timestamptz', amprocnum => '4',
amproc => 'btequalimage' },
{ amprocfamily => 'btree/datetime_ops', amproclefttype => 'timestamptz',
+ amprocrighttype => 'timestamptz', amprocnum => '6',
+ amproc => 'timestamp_skipsupport' },
+{ amprocfamily => 'btree/datetime_ops', amproclefttype => 'timestamptz',
amprocrighttype => 'date', amprocnum => '1',
amproc => 'timestamptz_cmp_date' },
{ amprocfamily => 'btree/datetime_ops', amproclefttype => 'timestamptz',
@@ -123,6 +135,8 @@
{ amprocfamily => 'btree/integer_ops', amproclefttype => 'int2',
amprocrighttype => 'int2', amprocnum => '4', amproc => 'btequalimage' },
{ amprocfamily => 'btree/integer_ops', amproclefttype => 'int2',
+ amprocrighttype => 'int2', amprocnum => '6', amproc => 'btint2skipsupport' },
+{ amprocfamily => 'btree/integer_ops', amproclefttype => 'int2',
amprocrighttype => 'int4', amprocnum => '1', amproc => 'btint24cmp' },
{ amprocfamily => 'btree/integer_ops', amproclefttype => 'int2',
amprocrighttype => 'int8', amprocnum => '1', amproc => 'btint28cmp' },
@@ -142,6 +156,8 @@
{ amprocfamily => 'btree/integer_ops', amproclefttype => 'int4',
amprocrighttype => 'int4', amprocnum => '4', amproc => 'btequalimage' },
{ amprocfamily => 'btree/integer_ops', amproclefttype => 'int4',
+ amprocrighttype => 'int4', amprocnum => '6', amproc => 'btint4skipsupport' },
+{ amprocfamily => 'btree/integer_ops', amproclefttype => 'int4',
amprocrighttype => 'int8', amprocnum => '1', amproc => 'btint48cmp' },
{ amprocfamily => 'btree/integer_ops', amproclefttype => 'int4',
amprocrighttype => 'int2', amprocnum => '1', amproc => 'btint42cmp' },
@@ -161,6 +177,8 @@
{ amprocfamily => 'btree/integer_ops', amproclefttype => 'int8',
amprocrighttype => 'int8', amprocnum => '4', amproc => 'btequalimage' },
{ amprocfamily => 'btree/integer_ops', amproclefttype => 'int8',
+ amprocrighttype => 'int8', amprocnum => '6', amproc => 'btint8skipsupport' },
+{ amprocfamily => 'btree/integer_ops', amproclefttype => 'int8',
amprocrighttype => 'int4', amprocnum => '1', amproc => 'btint84cmp' },
{ amprocfamily => 'btree/integer_ops', amproclefttype => 'int8',
amprocrighttype => 'int2', amprocnum => '1', amproc => 'btint82cmp' },
@@ -193,6 +211,8 @@
amprocrighttype => 'oid', amprocnum => '2', amproc => 'btoidsortsupport' },
{ amprocfamily => 'btree/oid_ops', amproclefttype => 'oid',
amprocrighttype => 'oid', amprocnum => '4', amproc => 'btequalimage' },
+{ amprocfamily => 'btree/oid_ops', amproclefttype => 'oid',
+ amprocrighttype => 'oid', amprocnum => '6', amproc => 'btoidskipsupport' },
{ amprocfamily => 'btree/oidvector_ops', amproclefttype => 'oidvector',
amprocrighttype => 'oidvector', amprocnum => '1',
amproc => 'btoidvectorcmp' },
@@ -261,6 +281,8 @@
amprocrighttype => 'uuid', amprocnum => '2', amproc => 'uuid_sortsupport' },
{ amprocfamily => 'btree/uuid_ops', amproclefttype => 'uuid',
amprocrighttype => 'uuid', amprocnum => '4', amproc => 'btequalimage' },
+{ amprocfamily => 'btree/uuid_ops', amproclefttype => 'uuid',
+ amprocrighttype => 'uuid', amprocnum => '6', amproc => 'uuid_skipsupport' },
{ amprocfamily => 'btree/record_ops', amproclefttype => 'record',
amprocrighttype => 'record', amprocnum => '1', amproc => 'btrecordcmp' },
{ amprocfamily => 'btree/record_image_ops', amproclefttype => 'record',
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index a28a15993a2..5d5be8ba4e1 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -1004,18 +1004,27 @@
{ oid => '3129', descr => 'sort support',
proname => 'btint2sortsupport', prorettype => 'void',
proargtypes => 'internal', prosrc => 'btint2sortsupport' },
+{ oid => '9290', descr => 'skip support',
+ proname => 'btint2skipsupport', prorettype => 'void',
+ proargtypes => 'internal', prosrc => 'btint2skipsupport' },
{ oid => '351', descr => 'less-equal-greater',
proname => 'btint4cmp', proleakproof => 't', prorettype => 'int4',
proargtypes => 'int4 int4', prosrc => 'btint4cmp' },
{ oid => '3130', descr => 'sort support',
proname => 'btint4sortsupport', prorettype => 'void',
proargtypes => 'internal', prosrc => 'btint4sortsupport' },
+{ oid => '9291', descr => 'skip support',
+ proname => 'btint4skipsupport', prorettype => 'void',
+ proargtypes => 'internal', prosrc => 'btint4skipsupport' },
{ oid => '842', descr => 'less-equal-greater',
proname => 'btint8cmp', proleakproof => 't', prorettype => 'int4',
proargtypes => 'int8 int8', prosrc => 'btint8cmp' },
{ oid => '3131', descr => 'sort support',
proname => 'btint8sortsupport', prorettype => 'void',
proargtypes => 'internal', prosrc => 'btint8sortsupport' },
+{ oid => '9292', descr => 'skip support',
+ proname => 'btint8skipsupport', prorettype => 'void',
+ proargtypes => 'internal', prosrc => 'btint8skipsupport' },
{ oid => '354', descr => 'less-equal-greater',
proname => 'btfloat4cmp', proleakproof => 't', prorettype => 'int4',
proargtypes => 'float4 float4', prosrc => 'btfloat4cmp' },
@@ -1034,12 +1043,18 @@
{ oid => '3134', descr => 'sort support',
proname => 'btoidsortsupport', prorettype => 'void',
proargtypes => 'internal', prosrc => 'btoidsortsupport' },
+{ oid => '9293', descr => 'skip support',
+ proname => 'btoidskipsupport', prorettype => 'void',
+ proargtypes => 'internal', prosrc => 'btoidskipsupport' },
{ oid => '404', descr => 'less-equal-greater',
proname => 'btoidvectorcmp', proleakproof => 't', prorettype => 'int4',
proargtypes => 'oidvector oidvector', prosrc => 'btoidvectorcmp' },
{ oid => '358', descr => 'less-equal-greater',
proname => 'btcharcmp', proleakproof => 't', prorettype => 'int4',
proargtypes => 'char char', prosrc => 'btcharcmp' },
+{ oid => '9294', descr => 'skip support',
+ proname => 'btcharskipsupport', prorettype => 'void',
+ proargtypes => 'internal', prosrc => 'btcharskipsupport' },
{ oid => '359', descr => 'less-equal-greater',
proname => 'btnamecmp', proleakproof => 't', prorettype => 'int4',
proargtypes => 'name name', prosrc => 'btnamecmp' },
@@ -2300,6 +2315,9 @@
{ oid => '3136', descr => 'sort support',
proname => 'date_sortsupport', prorettype => 'void',
proargtypes => 'internal', prosrc => 'date_sortsupport' },
+{ oid => '9295', descr => 'skip support',
+ proname => 'date_skipsupport', prorettype => 'void',
+ proargtypes => 'internal', prosrc => 'date_skipsupport' },
{ oid => '4133', descr => 'window RANGE support',
proname => 'in_range', prorettype => 'bool',
proargtypes => 'date date interval bool bool',
@@ -4497,6 +4515,9 @@
{ oid => '1693', descr => 'less-equal-greater',
proname => 'btboolcmp', proleakproof => 't', prorettype => 'int4',
proargtypes => 'bool bool', prosrc => 'btboolcmp' },
+{ oid => '9296', descr => 'skip support',
+ proname => 'btboolskipsupport', prorettype => 'void',
+ proargtypes => 'internal', prosrc => 'btboolskipsupport' },
{ oid => '1688', descr => 'hash',
proname => 'time_hash', prorettype => 'int4', proargtypes => 'time',
@@ -6376,6 +6397,9 @@
{ oid => '3137', descr => 'sort support',
proname => 'timestamp_sortsupport', prorettype => 'void',
proargtypes => 'internal', prosrc => 'timestamp_sortsupport' },
+{ oid => '9297', descr => 'skip support',
+ proname => 'timestamp_skipsupport', prorettype => 'void',
+ proargtypes => 'internal', prosrc => 'timestamp_skipsupport' },
{ oid => '4134', descr => 'window RANGE support',
proname => 'in_range', prorettype => 'bool',
@@ -9431,6 +9455,9 @@
{ oid => '3300', descr => 'sort support',
proname => 'uuid_sortsupport', prorettype => 'void',
proargtypes => 'internal', prosrc => 'uuid_sortsupport' },
+{ oid => '9298', descr => 'skip support',
+ proname => 'uuid_skipsupport', prorettype => 'void',
+ proargtypes => 'internal', prosrc => 'uuid_skipsupport' },
{ oid => '2961', descr => 'I/O',
proname => 'uuid_recv', prorettype => 'uuid', proargtypes => 'internal',
prosrc => 'uuid_recv' },
diff --git a/src/include/utils/skipsupport.h b/src/include/utils/skipsupport.h
new file mode 100644
index 00000000000..bc51847cf61
--- /dev/null
+++ b/src/include/utils/skipsupport.h
@@ -0,0 +1,98 @@
+/*-------------------------------------------------------------------------
+ *
+ * skipsupport.h
+ * Support routines for B-Tree skip scan.
+ *
+ * B-Tree operator classes for discrete types can optionally provide a support
+ * function for skipping. This is used during skip scans.
+ *
+ * A B-tree operator class that implements skip support provides B-tree index
+ * scans with a way of enumerating and iterating through every possible value
+ * from the domain of indexable values. This gives scans a way to determine
+ * the next value in line for a given skip array/scan key/skipped attribute.
+ * Scans request the next (or previous) value whenever they run out of tuples
+ * matching the skip array's current element value. The next (or previous)
+ * value can be used to relocate the scan; it is applied in combination with
+ * at least one additional lower-order non-skip key, taken from the query.
+ *
+ * Skip support is used by discrete type (e.g., integer and date) opclasses.
+ * Indexes with an attribute whose input opclass is of one of these types tend
+ * to store adjacent values in adjoining groups of index tuples. Each time a
+ * skip scan with skip support successfully guesses that the next value in the
+ * index (for a given skipped column) is indeed the value that skip support
+ * just incremented its skip array to, it will have saved the scan some work.
+ * The scan will have avoided an index probe that directly finds the next
+ * value that appears in the index. (When skip support guesses wrong, then it
+ * won't have saved any work, but it also won't have added any useless work.
+ * The failed attempt to locate exactly-matching index tuples acts just like
+ * an explicit probe would; it'll still find the index's true next value.)
+ *
+ * It usually isn't feasible to implement skip support for an opclass whose
+ * input type is continuous. The B-Tree code falls back on next-key sentinel
+ * values for any opclass that doesn't provide its own skip support function.
+ * This isn't really an implementation restriction; there is no benefit to
+ * providing skip support for an opclass where guessing that the next indexed
+ * value is the next possible indexable value never (or hardly ever) works out.
+ *
+ *
+ * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/include/utils/skipsupport.h
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef SKIPSUPPORT_H
+#define SKIPSUPPORT_H
+
+#include "utils/relcache.h"
+
+typedef struct SkipSupportData *SkipSupport;
+typedef Datum (*SkipSupportIncDec) (Relation rel,
+ Datum existing,
+ bool *overflow);
+
+/*
+ * State/callbacks used by skip arrays to procedurally generate elements.
+ *
+ * A BTSKIPSUPPORT_PROC function must set each and every field when called
+ * (there are no optional fields).
+ */
+typedef struct SkipSupportData
+{
+ /*
+ * low_elem and high_elem must be set with the lowest and highest possible
+ * values from the domain of indexable values (assuming ascending order)
+ */
+ Datum low_elem; /* lowest sorting/leftmost non-NULL value */
+ Datum high_elem; /* highest sorting/rightmost non-NULL value */
+
+ /*
+ * Decrement/increment functions.
+ *
+ * Returns a decremented/incremented copy of caller's existing datum,
+ * allocated in caller's memory context (for pass-by-reference types).
+ * It's not okay for these functions to leak any memory.
+ *
+ * When the decrement function (or increment function) is called with a
+ * value that already matches low_elem (or high_elem), function must set
+ * the *overflow argument. The return value is treated as undefined by
+ * the B-Tree code; it shouldn't need to be (and won't be) pfree'd.
+ *
+ * The B-Tree code's "existing" datum argument is often just a straight
+ * copy of a value from an index tuple. Operator classes must accept
+ * every possible representational variation within the underlying type.
+ * On the other hand, opclasses are _not_ required to preserve information
+ * that doesn't affect how datums are sorted (e.g., skip support for a
+ * fixed precision numeric type needn't preserve datum display scale).
+ * Operator class decrement/increment functions will never be called with
+ * a NULL "existing" argument, either.
+ */
+ SkipSupportIncDec decrement;
+ SkipSupportIncDec increment;
+} SkipSupportData;
+
+extern SkipSupport PrepareSkipSupportFromOpclass(Oid opfamily, Oid opcintype,
+ bool reverse);
+
+#endif /* SKIPSUPPORT_H */
diff --git a/src/test/regress/expected/alter_generic.out b/src/test/regress/expected/alter_generic.out
index 0c274d56a04..23bf33f10a9 100644
--- a/src/test/regress/expected/alter_generic.out
+++ b/src/test/regress/expected/alter_generic.out
@@ -362,9 +362,9 @@ ERROR: invalid operator number 0, must be between 1 and 5
ALTER OPERATOR FAMILY alt_opf4 USING btree ADD OPERATOR 1 < ; -- operator without argument types
ERROR: operator argument types must be specified in ALTER OPERATOR FAMILY
ALTER OPERATOR FAMILY alt_opf4 USING btree ADD FUNCTION 0 btint42cmp(int4, int2); -- invalid options parsing function
-ERROR: invalid function number 0, must be between 1 and 5
-ALTER OPERATOR FAMILY alt_opf4 USING btree ADD FUNCTION 6 btint42cmp(int4, int2); -- function number should be between 1 and 5
-ERROR: invalid function number 6, must be between 1 and 5
+ERROR: invalid function number 0, must be between 1 and 6
+ALTER OPERATOR FAMILY alt_opf4 USING btree ADD FUNCTION 7 btint42cmp(int4, int2); -- function number should be between 1 and 6
+ERROR: invalid function number 7, must be between 1 and 6
ALTER OPERATOR FAMILY alt_opf4 USING btree ADD STORAGE invalid_storage; -- Ensure STORAGE is not a part of ALTER OPERATOR FAMILY
ERROR: STORAGE cannot be specified in ALTER OPERATOR FAMILY
DROP OPERATOR FAMILY alt_opf4 USING btree;
@@ -505,6 +505,10 @@ ALTER OPERATOR FAMILY alt_opf18 USING btree ADD
ALTER OPERATOR FAMILY alt_opf18 USING btree
ADD FUNCTION 4 (int4, int2) btequalimage(oid);
ERROR: ordering equal image functions must not be cross-type
+-- Should fail. Not allowed to have cross-type skip support function.
+ALTER OPERATOR FAMILY alt_opf18 USING btree
+ ADD FUNCTION 6 (int4, int2) btint4skipsupport(internal);
+ERROR: btree skip support functions must not be cross-type
ALTER OPERATOR FAMILY alt_opf18 USING btree DROP FUNCTION 2 (int4, int4);
ERROR: function 2(integer,integer) does not exist in operator family "alt_opf18"
DROP OPERATOR FAMILY alt_opf18 USING btree;
diff --git a/src/test/regress/expected/btree_index.out b/src/test/regress/expected/btree_index.out
index 8879554c3f7..bfb1a286ea4 100644
--- a/src/test/regress/expected/btree_index.out
+++ b/src/test/regress/expected/btree_index.out
@@ -581,6 +581,47 @@ alter table btree_tall_tbl alter COLUMN t set storage plain;
create index btree_tall_idx on btree_tall_tbl (t, id) with (fillfactor = 10);
insert into btree_tall_tbl select g, repeat('x', 250)
from generate_series(1, 130) g;
+insert into btree_tall_tbl select g, NULL
+from generate_series(50, 60) g;
+--
+-- Test for skip scan with type that lacks skip support (text)
+--
+set enable_seqscan to false;
+set enable_bitmapscan to false;
+-- Forwards scan
+SELECT id FROM btree_tall_tbl WHERE id = 55 ORDER BY t, id;
+ id
+----
+ 55
+ 55
+(2 rows)
+
+explain (costs off)
+SELECT id FROM btree_tall_tbl WHERE id = 55 ORDER BY t, id;
+ QUERY PLAN
+--------------------------------------------------------
+ Index Only Scan using btree_tall_idx on btree_tall_tbl
+ Index Cond: (id = 55)
+(2 rows)
+
+-- Backwards scan
+SELECT id FROM btree_tall_tbl WHERE id = 55 ORDER BY t DESC, id DESC;
+ id
+----
+ 55
+ 55
+(2 rows)
+
+explain (costs off)
+SELECT id FROM btree_tall_tbl WHERE id = 55 ORDER BY t DESC, id DESC;
+ QUERY PLAN
+-----------------------------------------------------------------
+ Index Only Scan Backward using btree_tall_idx on btree_tall_tbl
+ Index Cond: (id = 55)
+(2 rows)
+
+reset enable_seqscan;
+reset enable_bitmapscan;
--
-- Test for multilevel page deletion
--
diff --git a/src/test/regress/expected/create_index.out b/src/test/regress/expected/create_index.out
index 15be0043ad4..2cfb26699be 100644
--- a/src/test/regress/expected/create_index.out
+++ b/src/test/regress/expected/create_index.out
@@ -1637,7 +1637,9 @@ DROP TABLE syscol_table;
-- Tests for IS NULL/IS NOT NULL with b-tree indexes
--
CREATE TABLE onek_with_null AS SELECT unique1, unique2 FROM onek;
-INSERT INTO onek_with_null (unique1,unique2) VALUES (NULL, -1), (NULL, NULL);
+INSERT INTO onek_with_null(unique1, unique2)
+VALUES (NULL, -1), (NULL, 2_147_483_647), (NULL, NULL),
+ (100, NULL), (500, NULL);
CREATE UNIQUE INDEX onek_nulltest ON onek_with_null (unique2,unique1);
SET enable_seqscan = OFF;
SET enable_indexscan = ON;
@@ -1645,7 +1647,7 @@ SET enable_bitmapscan = ON;
SELECT count(*) FROM onek_with_null WHERE unique1 IS NULL;
count
-------
- 2
+ 3
(1 row)
SELECT count(*) FROM onek_with_null WHERE unique1 IS NULL AND unique2 IS NULL;
@@ -1657,13 +1659,13 @@ SELECT count(*) FROM onek_with_null WHERE unique1 IS NULL AND unique2 IS NULL;
SELECT count(*) FROM onek_with_null WHERE unique1 IS NOT NULL;
count
-------
- 1000
+ 1002
(1 row)
SELECT count(*) FROM onek_with_null WHERE unique1 IS NULL AND unique2 IS NOT NULL;
count
-------
- 1
+ 2
(1 row)
SELECT count(*) FROM onek_with_null WHERE unique1 IS NOT NULL AND unique1 > 500;
@@ -1678,12 +1680,18 @@ SELECT count(*) FROM onek_with_null WHERE unique1 IS NULL AND unique1 > 500;
0
(1 row)
+SELECT unique1, unique2 FROM onek_with_null WHERE unique1 = 500 ORDER BY unique2 DESC, unique1 DESC LIMIT 1;
+ unique1 | unique2
+---------+---------
+ 500 |
+(1 row)
+
DROP INDEX onek_nulltest;
CREATE UNIQUE INDEX onek_nulltest ON onek_with_null (unique2 desc,unique1);
SELECT count(*) FROM onek_with_null WHERE unique1 IS NULL;
count
-------
- 2
+ 3
(1 row)
SELECT count(*) FROM onek_with_null WHERE unique1 IS NULL AND unique2 IS NULL;
@@ -1695,13 +1703,13 @@ SELECT count(*) FROM onek_with_null WHERE unique1 IS NULL AND unique2 IS NULL;
SELECT count(*) FROM onek_with_null WHERE unique1 IS NOT NULL;
count
-------
- 1000
+ 1002
(1 row)
SELECT count(*) FROM onek_with_null WHERE unique1 IS NULL AND unique2 IS NOT NULL;
count
-------
- 1
+ 2
(1 row)
SELECT count(*) FROM onek_with_null WHERE unique1 IS NOT NULL AND unique1 > 500;
@@ -1722,12 +1730,18 @@ SELECT count(*) FROM onek_with_null WHERE unique1 IS NULL AND unique2 IN (-1, 0,
1
(1 row)
+SELECT unique1, unique2 FROM onek_with_null WHERE unique1 = 500 ORDER BY unique2 DESC, unique1 DESC LIMIT 1;
+ unique1 | unique2
+---------+---------
+ 500 |
+(1 row)
+
DROP INDEX onek_nulltest;
CREATE UNIQUE INDEX onek_nulltest ON onek_with_null (unique2 desc nulls last,unique1);
SELECT count(*) FROM onek_with_null WHERE unique1 IS NULL;
count
-------
- 2
+ 3
(1 row)
SELECT count(*) FROM onek_with_null WHERE unique1 IS NULL AND unique2 IS NULL;
@@ -1739,13 +1753,13 @@ SELECT count(*) FROM onek_with_null WHERE unique1 IS NULL AND unique2 IS NULL;
SELECT count(*) FROM onek_with_null WHERE unique1 IS NOT NULL;
count
-------
- 1000
+ 1002
(1 row)
SELECT count(*) FROM onek_with_null WHERE unique1 IS NULL AND unique2 IS NOT NULL;
count
-------
- 1
+ 2
(1 row)
SELECT count(*) FROM onek_with_null WHERE unique1 IS NOT NULL AND unique1 > 500;
@@ -1760,12 +1774,18 @@ SELECT count(*) FROM onek_with_null WHERE unique1 IS NULL AND unique1 > 500;
0
(1 row)
+SELECT unique1, unique2 FROM onek_with_null WHERE unique1 = 500 ORDER BY unique2 DESC, unique1 DESC LIMIT 1;
+ unique1 | unique2
+---------+---------
+ 500 |
+(1 row)
+
DROP INDEX onek_nulltest;
CREATE UNIQUE INDEX onek_nulltest ON onek_with_null (unique2 nulls first,unique1);
SELECT count(*) FROM onek_with_null WHERE unique1 IS NULL;
count
-------
- 2
+ 3
(1 row)
SELECT count(*) FROM onek_with_null WHERE unique1 IS NULL AND unique2 IS NULL;
@@ -1777,13 +1797,13 @@ SELECT count(*) FROM onek_with_null WHERE unique1 IS NULL AND unique2 IS NULL;
SELECT count(*) FROM onek_with_null WHERE unique1 IS NOT NULL;
count
-------
- 1000
+ 1002
(1 row)
SELECT count(*) FROM onek_with_null WHERE unique1 IS NULL AND unique2 IS NOT NULL;
count
-------
- 1
+ 2
(1 row)
SELECT count(*) FROM onek_with_null WHERE unique1 IS NOT NULL AND unique1 > 500;
@@ -1798,6 +1818,12 @@ SELECT count(*) FROM onek_with_null WHERE unique1 IS NULL AND unique1 > 500;
0
(1 row)
+SELECT unique1, unique2 FROM onek_with_null WHERE unique1 = 500 ORDER BY unique2 DESC, unique1 DESC LIMIT 1;
+ unique1 | unique2
+---------+---------
+ 500 |
+(1 row)
+
DROP INDEX onek_nulltest;
-- Check initial-positioning logic too
CREATE UNIQUE INDEX onek_nulltest ON onek_with_null (unique2);
@@ -1829,20 +1855,24 @@ SELECT unique1, unique2 FROM onek_with_null WHERE unique2 >= 0
(2 rows)
SELECT unique1, unique2 FROM onek_with_null
- ORDER BY unique2 DESC LIMIT 2;
- unique1 | unique2
----------+---------
- |
- 278 | 999
-(2 rows)
+ ORDER BY unique2 DESC LIMIT 5;
+ unique1 | unique2
+---------+------------
+ 500 |
+ 100 |
+ |
+ | 2147483647
+ 278 | 999
+(5 rows)
SELECT unique1, unique2 FROM onek_with_null WHERE unique2 >= -1
- ORDER BY unique2 DESC LIMIT 2;
- unique1 | unique2
----------+---------
- 278 | 999
- 0 | 998
-(2 rows)
+ ORDER BY unique2 DESC LIMIT 3;
+ unique1 | unique2
+---------+------------
+ | 2147483647
+ 278 | 999
+ 0 | 998
+(3 rows)
SELECT unique1, unique2 FROM onek_with_null WHERE unique2 < 999
ORDER BY unique2 DESC LIMIT 2;
@@ -2247,7 +2277,8 @@ SELECT count(*) FROM dupindexcols
(1 row)
--
--- Check that index scans with =ANY indexquals return rows in index order
+-- Check that index scans with SAOP array and/or skip array indexquals
+-- return rows in index order
--
explain (costs off)
SELECT unique1 FROM tenk1
@@ -2269,7 +2300,7 @@ ORDER BY unique1;
42
(3 rows)
--- Non-required array scan key on "tenthous":
+-- Skip array on "thousand", SAOP array on "tenthous":
explain (costs off)
SELECT thousand, tenthous FROM tenk1
WHERE thousand < 2 AND tenthous IN (1001,3000)
@@ -2289,7 +2320,7 @@ ORDER BY thousand;
1 | 1001
(2 rows)
--- Non-required array scan key on "tenthous", backward scan:
+-- Skip array on "thousand", SAOP array on "tenthous", backward scan:
explain (costs off)
SELECT thousand, tenthous FROM tenk1
WHERE thousand < 2 AND tenthous IN (1001,3000)
@@ -2309,6 +2340,25 @@ ORDER BY thousand DESC, tenthous DESC;
0 | 3000
(2 rows)
+explain (costs off)
+SELECT thousand, tenthous FROM tenk1
+WHERE thousand > 995 and tenthous in (998, 999)
+ORDER BY thousand desc;
+ QUERY PLAN
+--------------------------------------------------------------------------------
+ Index Only Scan Backward using tenk1_thous_tenthous on tenk1
+ Index Cond: ((thousand > 995) AND (tenthous = ANY ('{998,999}'::integer[])))
+(2 rows)
+
+SELECT thousand, tenthous FROM tenk1
+WHERE thousand > 995 and tenthous in (998, 999)
+ORDER BY thousand desc;
+ thousand | tenthous
+----------+----------
+ 999 | 999
+ 998 | 998
+(2 rows)
+
--
-- Check elimination of redundant and contradictory index quals
--
@@ -2340,6 +2390,45 @@ SELECT unique1 FROM tenk1 WHERE unique1 = ANY('{7, 14, 22}') and unique1 = ANY('
(0 rows)
explain (costs off)
+SELECT unique1 FROM tenk1 WHERE unique1 = ANY(NULL);
+ QUERY PLAN
+-------------------------------------------------
+ Index Only Scan using tenk1_unique1 on tenk1
+ Index Cond: (unique1 = ANY (NULL::integer[]))
+(2 rows)
+
+SELECT unique1 FROM tenk1 WHERE unique1 = ANY(NULL);
+ unique1
+---------
+(0 rows)
+
+explain (costs off)
+SELECT unique1 FROM tenk1 WHERE unique1 = ANY('{NULL,NULL,NULL}');
+ QUERY PLAN
+---------------------------------------------------------------
+ Index Only Scan using tenk1_unique1 on tenk1
+ Index Cond: (unique1 = ANY ('{NULL,NULL,NULL}'::integer[]))
+(2 rows)
+
+SELECT unique1 FROM tenk1 WHERE unique1 = ANY('{NULL,NULL,NULL}');
+ unique1
+---------
+(0 rows)
+
+explain (costs off)
+SELECT unique1 FROM tenk1 WHERE unique1 IS NULL AND unique1 IS NULL;
+ QUERY PLAN
+---------------------------------------------------------
+ Index Only Scan using tenk1_unique1 on tenk1
+ Index Cond: ((unique1 IS NULL) AND (unique1 IS NULL))
+(2 rows)
+
+SELECT unique1 FROM tenk1 WHERE unique1 IS NULL AND unique1 IS NULL;
+ unique1
+---------
+(0 rows)
+
+explain (costs off)
SELECT unique1 FROM tenk1 WHERE unique1 IN (1, 42, 7) and unique1 = 1;
QUERY PLAN
---------------------------------------------------------------------------
@@ -2462,6 +2551,44 @@ SELECT unique1 FROM tenk1 WHERE (thousand, tenthous) > (NULL, 5);
---------
(0 rows)
+-- Skip array redundancy (pair of redundant low_compare inequalities)
+explain (costs off)
+SELECT thousand, tenthous FROM tenk1
+WHERE thousand > -1 and thousand >= 0 AND tenthous = 3000
+ORDER BY thousand;
+ QUERY PLAN
+--------------------------------------------------------------------------------------
+ Index Only Scan using tenk1_thous_tenthous on tenk1
+ Index Cond: ((thousand > '-1'::integer) AND (thousand >= 0) AND (tenthous = 3000))
+(2 rows)
+
+SELECT thousand, tenthous FROM tenk1
+WHERE thousand > -1 and thousand >= 0 AND tenthous = 3000
+ORDER BY thousand;
+ thousand | tenthous
+----------+----------
+ 0 | 3000
+(1 row)
+
+-- Skip array redundancy (pair of redundant high_compare inequalities)
+explain (costs off)
+SELECT thousand, tenthous FROM tenk1
+WHERE thousand < 3 and thousand <= 2 AND tenthous = 1001
+ORDER BY thousand;
+ QUERY PLAN
+--------------------------------------------------------------------------
+ Index Only Scan using tenk1_thous_tenthous on tenk1
+ Index Cond: ((thousand < 3) AND (thousand <= 2) AND (tenthous = 1001))
+(2 rows)
+
+SELECT thousand, tenthous FROM tenk1
+WHERE thousand < 3 and thousand <= 2 AND tenthous = 1001
+ORDER BY thousand;
+ thousand | tenthous
+----------+----------
+ 1 | 1001
+(1 row)
+
--
-- Check elimination of constant-NULL subexpressions
--
diff --git a/src/test/regress/expected/psql.out b/src/test/regress/expected/psql.out
index b1d12585eae..cf48ae6d0c2 100644
--- a/src/test/regress/expected/psql.out
+++ b/src/test/regress/expected/psql.out
@@ -5332,9 +5332,10 @@ Function | in_range(time without time zone,time without time zone,i
btree | uuid_ops | uuid | uuid | 1 | uuid_cmp
btree | uuid_ops | uuid | uuid | 2 | uuid_sortsupport
btree | uuid_ops | uuid | uuid | 4 | btequalimage
+ btree | uuid_ops | uuid | uuid | 6 | uuid_skipsupport
hash | uuid_ops | uuid | uuid | 1 | uuid_hash
hash | uuid_ops | uuid | uuid | 2 | uuid_hash_extended
-(5 rows)
+(6 rows)
-- check \dconfig
set work_mem = 10240;
diff --git a/src/test/regress/sql/alter_generic.sql b/src/test/regress/sql/alter_generic.sql
index de58d268d31..5e20dc63337 100644
--- a/src/test/regress/sql/alter_generic.sql
+++ b/src/test/regress/sql/alter_generic.sql
@@ -310,7 +310,7 @@ ALTER OPERATOR FAMILY alt_opf4 USING btree ADD OPERATOR 6 < (int4, int2); -- ope
ALTER OPERATOR FAMILY alt_opf4 USING btree ADD OPERATOR 0 < (int4, int2); -- operator number should be between 1 and 5
ALTER OPERATOR FAMILY alt_opf4 USING btree ADD OPERATOR 1 < ; -- operator without argument types
ALTER OPERATOR FAMILY alt_opf4 USING btree ADD FUNCTION 0 btint42cmp(int4, int2); -- invalid options parsing function
-ALTER OPERATOR FAMILY alt_opf4 USING btree ADD FUNCTION 6 btint42cmp(int4, int2); -- function number should be between 1 and 5
+ALTER OPERATOR FAMILY alt_opf4 USING btree ADD FUNCTION 7 btint42cmp(int4, int2); -- function number should be between 1 and 6
ALTER OPERATOR FAMILY alt_opf4 USING btree ADD STORAGE invalid_storage; -- Ensure STORAGE is not a part of ALTER OPERATOR FAMILY
DROP OPERATOR FAMILY alt_opf4 USING btree;
@@ -444,6 +444,9 @@ ALTER OPERATOR FAMILY alt_opf18 USING btree ADD
-- Should fail. Not allowed to have cross-type equalimage function.
ALTER OPERATOR FAMILY alt_opf18 USING btree
ADD FUNCTION 4 (int4, int2) btequalimage(oid);
+-- Should fail. Not allowed to have cross-type skip support function.
+ALTER OPERATOR FAMILY alt_opf18 USING btree
+ ADD FUNCTION 6 (int4, int2) btint4skipsupport(internal);
ALTER OPERATOR FAMILY alt_opf18 USING btree DROP FUNCTION 2 (int4, int4);
DROP OPERATOR FAMILY alt_opf18 USING btree;
diff --git a/src/test/regress/sql/btree_index.sql b/src/test/regress/sql/btree_index.sql
index 670ad5c6e6a..68c61dbc7d1 100644
--- a/src/test/regress/sql/btree_index.sql
+++ b/src/test/regress/sql/btree_index.sql
@@ -327,6 +327,27 @@ alter table btree_tall_tbl alter COLUMN t set storage plain;
create index btree_tall_idx on btree_tall_tbl (t, id) with (fillfactor = 10);
insert into btree_tall_tbl select g, repeat('x', 250)
from generate_series(1, 130) g;
+insert into btree_tall_tbl select g, NULL
+from generate_series(50, 60) g;
+
+--
+-- Test for skip scan with type that lacks skip support (text)
+--
+set enable_seqscan to false;
+set enable_bitmapscan to false;
+
+-- Forwards scan
+SELECT id FROM btree_tall_tbl WHERE id = 55 ORDER BY t, id;
+explain (costs off)
+SELECT id FROM btree_tall_tbl WHERE id = 55 ORDER BY t, id;
+
+-- Backwards scan
+SELECT id FROM btree_tall_tbl WHERE id = 55 ORDER BY t DESC, id DESC;
+explain (costs off)
+SELECT id FROM btree_tall_tbl WHERE id = 55 ORDER BY t DESC, id DESC;
+
+reset enable_seqscan;
+reset enable_bitmapscan;
--
-- Test for multilevel page deletion
diff --git a/src/test/regress/sql/create_index.sql b/src/test/regress/sql/create_index.sql
index 6b3852dddd8..cd90b1c3a8f 100644
--- a/src/test/regress/sql/create_index.sql
+++ b/src/test/regress/sql/create_index.sql
@@ -650,7 +650,9 @@ DROP TABLE syscol_table;
--
CREATE TABLE onek_with_null AS SELECT unique1, unique2 FROM onek;
-INSERT INTO onek_with_null (unique1,unique2) VALUES (NULL, -1), (NULL, NULL);
+INSERT INTO onek_with_null(unique1, unique2)
+VALUES (NULL, -1), (NULL, 2_147_483_647), (NULL, NULL),
+ (100, NULL), (500, NULL);
CREATE UNIQUE INDEX onek_nulltest ON onek_with_null (unique2,unique1);
SET enable_seqscan = OFF;
@@ -663,6 +665,7 @@ SELECT count(*) FROM onek_with_null WHERE unique1 IS NOT NULL;
SELECT count(*) FROM onek_with_null WHERE unique1 IS NULL AND unique2 IS NOT NULL;
SELECT count(*) FROM onek_with_null WHERE unique1 IS NOT NULL AND unique1 > 500;
SELECT count(*) FROM onek_with_null WHERE unique1 IS NULL AND unique1 > 500;
+SELECT unique1, unique2 FROM onek_with_null WHERE unique1 = 500 ORDER BY unique2 DESC, unique1 DESC LIMIT 1;
DROP INDEX onek_nulltest;
@@ -675,6 +678,7 @@ SELECT count(*) FROM onek_with_null WHERE unique1 IS NULL AND unique2 IS NOT NUL
SELECT count(*) FROM onek_with_null WHERE unique1 IS NOT NULL AND unique1 > 500;
SELECT count(*) FROM onek_with_null WHERE unique1 IS NULL AND unique1 > 500;
SELECT count(*) FROM onek_with_null WHERE unique1 IS NULL AND unique2 IN (-1, 0, 1);
+SELECT unique1, unique2 FROM onek_with_null WHERE unique1 = 500 ORDER BY unique2 DESC, unique1 DESC LIMIT 1;
DROP INDEX onek_nulltest;
@@ -686,6 +690,7 @@ SELECT count(*) FROM onek_with_null WHERE unique1 IS NOT NULL;
SELECT count(*) FROM onek_with_null WHERE unique1 IS NULL AND unique2 IS NOT NULL;
SELECT count(*) FROM onek_with_null WHERE unique1 IS NOT NULL AND unique1 > 500;
SELECT count(*) FROM onek_with_null WHERE unique1 IS NULL AND unique1 > 500;
+SELECT unique1, unique2 FROM onek_with_null WHERE unique1 = 500 ORDER BY unique2 DESC, unique1 DESC LIMIT 1;
DROP INDEX onek_nulltest;
@@ -697,6 +702,7 @@ SELECT count(*) FROM onek_with_null WHERE unique1 IS NOT NULL;
SELECT count(*) FROM onek_with_null WHERE unique1 IS NULL AND unique2 IS NOT NULL;
SELECT count(*) FROM onek_with_null WHERE unique1 IS NOT NULL AND unique1 > 500;
SELECT count(*) FROM onek_with_null WHERE unique1 IS NULL AND unique1 > 500;
+SELECT unique1, unique2 FROM onek_with_null WHERE unique1 = 500 ORDER BY unique2 DESC, unique1 DESC LIMIT 1;
DROP INDEX onek_nulltest;
@@ -716,9 +722,9 @@ SELECT unique1, unique2 FROM onek_with_null WHERE unique2 >= 0
ORDER BY unique2 LIMIT 2;
SELECT unique1, unique2 FROM onek_with_null
- ORDER BY unique2 DESC LIMIT 2;
+ ORDER BY unique2 DESC LIMIT 5;
SELECT unique1, unique2 FROM onek_with_null WHERE unique2 >= -1
- ORDER BY unique2 DESC LIMIT 2;
+ ORDER BY unique2 DESC LIMIT 3;
SELECT unique1, unique2 FROM onek_with_null WHERE unique2 < 999
ORDER BY unique2 DESC LIMIT 2;
@@ -852,7 +858,8 @@ SELECT count(*) FROM dupindexcols
WHERE f1 BETWEEN 'WA' AND 'ZZZ' and id < 1000 and f1 ~<~ 'YX';
--
--- Check that index scans with =ANY indexquals return rows in index order
+-- Check that index scans with SAOP array and/or skip array indexquals
+-- return rows in index order
--
explain (costs off)
@@ -864,7 +871,7 @@ SELECT unique1 FROM tenk1
WHERE unique1 IN (1,42,7)
ORDER BY unique1;
--- Non-required array scan key on "tenthous":
+-- Skip array on "thousand", SAOP array on "tenthous":
explain (costs off)
SELECT thousand, tenthous FROM tenk1
WHERE thousand < 2 AND tenthous IN (1001,3000)
@@ -874,7 +881,7 @@ SELECT thousand, tenthous FROM tenk1
WHERE thousand < 2 AND tenthous IN (1001,3000)
ORDER BY thousand;
--- Non-required array scan key on "tenthous", backward scan:
+-- Skip array on "thousand", SAOP array on "tenthous", backward scan:
explain (costs off)
SELECT thousand, tenthous FROM tenk1
WHERE thousand < 2 AND tenthous IN (1001,3000)
@@ -884,6 +891,15 @@ SELECT thousand, tenthous FROM tenk1
WHERE thousand < 2 AND tenthous IN (1001,3000)
ORDER BY thousand DESC, tenthous DESC;
+explain (costs off)
+SELECT thousand, tenthous FROM tenk1
+WHERE thousand > 995 and tenthous in (998, 999)
+ORDER BY thousand desc;
+
+SELECT thousand, tenthous FROM tenk1
+WHERE thousand > 995 and tenthous in (998, 999)
+ORDER BY thousand desc;
+
--
-- Check elimination of redundant and contradictory index quals
--
@@ -898,6 +914,21 @@ SELECT unique1 FROM tenk1 WHERE unique1 = ANY('{7, 14, 22}') and unique1 = ANY('
SELECT unique1 FROM tenk1 WHERE unique1 = ANY('{7, 14, 22}') and unique1 = ANY('{33, 44}'::bigint[]);
explain (costs off)
+SELECT unique1 FROM tenk1 WHERE unique1 = ANY(NULL);
+
+SELECT unique1 FROM tenk1 WHERE unique1 = ANY(NULL);
+
+explain (costs off)
+SELECT unique1 FROM tenk1 WHERE unique1 = ANY('{NULL,NULL,NULL}');
+
+SELECT unique1 FROM tenk1 WHERE unique1 = ANY('{NULL,NULL,NULL}');
+
+explain (costs off)
+SELECT unique1 FROM tenk1 WHERE unique1 IS NULL AND unique1 IS NULL;
+
+SELECT unique1 FROM tenk1 WHERE unique1 IS NULL AND unique1 IS NULL;
+
+explain (costs off)
SELECT unique1 FROM tenk1 WHERE unique1 IN (1, 42, 7) and unique1 = 1;
SELECT unique1 FROM tenk1 WHERE unique1 IN (1, 42, 7) and unique1 = 1;
@@ -942,6 +973,26 @@ SELECT unique1 FROM tenk1 WHERE (thousand, tenthous) > (NULL, 5);
SELECT unique1 FROM tenk1 WHERE (thousand, tenthous) > (NULL, 5);
+-- Skip array redundancy (pair of redundant low_compare inequalities)
+explain (costs off)
+SELECT thousand, tenthous FROM tenk1
+WHERE thousand > -1 and thousand >= 0 AND tenthous = 3000
+ORDER BY thousand;
+
+SELECT thousand, tenthous FROM tenk1
+WHERE thousand > -1 and thousand >= 0 AND tenthous = 3000
+ORDER BY thousand;
+
+-- Skip array redundancy (pair of redundant high_compare inequalities)
+explain (costs off)
+SELECT thousand, tenthous FROM tenk1
+WHERE thousand < 3 and thousand <= 2 AND tenthous = 1001
+ORDER BY thousand;
+
+SELECT thousand, tenthous FROM tenk1
+WHERE thousand < 3 and thousand <= 2 AND tenthous = 1001
+ORDER BY thousand;
+
--
-- Check elimination of constant-NULL subexpressions
--
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index c3f05796a7c..229fbff47ae 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -2754,6 +2754,8 @@ SimpleStringListCell
SingleBoundSortItem
Size
SkipPages
+SkipSupport
+SkipSupportData
SlabBlock
SlabContext
SlabSlot