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-rw-r--r--src/backend/commands/analyze.c13
-rw-r--r--src/backend/commands/statscmds.c108
-rw-r--r--src/backend/nodes/copyfuncs.c15
-rw-r--r--src/backend/nodes/equalfuncs.c13
-rw-r--r--src/backend/nodes/outfuncs.c13
-rw-r--r--src/backend/parser/gram.y31
-rw-r--r--src/backend/statistics/extended_stats.c150
-rw-r--r--src/backend/statistics/mcv.c15
-rw-r--r--src/backend/tcop/utility.c12
9 files changed, 357 insertions, 13 deletions
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index ed0d4e6d4ff..7accb950eb1 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -307,7 +307,8 @@ do_analyze_rel(Relation onerel, VacuumParams *params,
VacAttrStats **vacattrstats;
AnlIndexData *indexdata;
int targrows,
- numrows;
+ numrows,
+ minrows;
double totalrows,
totaldeadrows;
HeapTuple *rows;
@@ -492,6 +493,16 @@ do_analyze_rel(Relation onerel, VacuumParams *params,
}
/*
+ * Look at extended statistics objects too, as those may define custom
+ * statistics target. So we may need to sample more rows and then build
+ * the statistics with enough detail.
+ */
+ minrows = ComputeExtStatisticsRows(onerel, attr_cnt, vacattrstats);
+
+ if (targrows < minrows)
+ targrows = minrows;
+
+ /*
* Acquire the sample rows
*/
rows = (HeapTuple *) palloc(targrows * sizeof(HeapTuple));
diff --git a/src/backend/commands/statscmds.c b/src/backend/commands/statscmds.c
index 34d11c2a980..f51eb7bb64e 100644
--- a/src/backend/commands/statscmds.c
+++ b/src/backend/commands/statscmds.c
@@ -14,6 +14,7 @@
*/
#include "postgres.h"
+#include "access/heapam.h"
#include "access/relation.h"
#include "access/relscan.h"
#include "access/table.h"
@@ -21,6 +22,7 @@
#include "catalog/dependency.h"
#include "catalog/indexing.h"
#include "catalog/namespace.h"
+#include "catalog/objectaccess.h"
#include "catalog/pg_namespace.h"
#include "catalog/pg_statistic_ext.h"
#include "catalog/pg_statistic_ext_data.h"
@@ -29,6 +31,7 @@
#include "miscadmin.h"
#include "statistics/statistics.h"
#include "utils/builtins.h"
+#include "utils/fmgroids.h"
#include "utils/inval.h"
#include "utils/memutils.h"
#include "utils/rel.h"
@@ -336,6 +339,7 @@ CreateStatistics(CreateStatsStmt *stmt)
values[Anum_pg_statistic_ext_stxrelid - 1] = ObjectIdGetDatum(relid);
values[Anum_pg_statistic_ext_stxname - 1] = NameGetDatum(&stxname);
values[Anum_pg_statistic_ext_stxnamespace - 1] = ObjectIdGetDatum(namespaceId);
+ values[Anum_pg_statistic_ext_stxstattarget - 1] = Int32GetDatum(-1);
values[Anum_pg_statistic_ext_stxowner - 1] = ObjectIdGetDatum(stxowner);
values[Anum_pg_statistic_ext_stxkeys - 1] = PointerGetDatum(stxkeys);
values[Anum_pg_statistic_ext_stxkind - 1] = PointerGetDatum(stxkind);
@@ -415,6 +419,110 @@ CreateStatistics(CreateStatsStmt *stmt)
}
/*
+ * ALTER STATISTICS
+ */
+ObjectAddress
+AlterStatistics(AlterStatsStmt *stmt)
+{
+ Relation rel;
+ Oid stxoid;
+ HeapTuple oldtup;
+ HeapTuple newtup;
+ Datum repl_val[Natts_pg_statistic_ext];
+ bool repl_null[Natts_pg_statistic_ext];
+ bool repl_repl[Natts_pg_statistic_ext];
+ ObjectAddress address;
+ int newtarget = stmt->stxstattarget;
+
+ /* Limit statistics target to a sane range */
+ if (newtarget < -1)
+ {
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ errmsg("statistics target %d is too low",
+ newtarget)));
+ }
+ else if (newtarget > 10000)
+ {
+ newtarget = 10000;
+ ereport(WARNING,
+ (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ errmsg("lowering statistics target to %d",
+ newtarget)));
+ }
+
+ /* lookup OID of the statistics object */
+ stxoid = get_statistics_object_oid(stmt->defnames, stmt->missing_ok);
+
+ /*
+ * If we got here and the OID is not valid, it means the statistics
+ * does not exist, but the command specified IF EXISTS. So report
+ * this as a simple NOTICE and we're done.
+ */
+ if (!OidIsValid(stxoid))
+ {
+ char *schemaname;
+ char *statname;
+
+ Assert(stmt->missing_ok);
+
+ DeconstructQualifiedName(stmt->defnames, &schemaname, &statname);
+
+ if (schemaname)
+ ereport(NOTICE,
+ (errmsg("statistics object \"%s.%s\" does not exist, skipping",
+ schemaname, statname)));
+ else
+ ereport(NOTICE,
+ (errmsg("statistics object \"%s\" does not exist, skipping",
+ statname)));
+
+ return InvalidObjectAddress;
+ }
+
+ /* Search pg_statistic_ext */
+ rel = table_open(StatisticExtRelationId, RowExclusiveLock);
+
+ oldtup = SearchSysCache1(STATEXTOID, ObjectIdGetDatum(stxoid));
+
+ /* Must be owner of the existing statistics object */
+ if (!pg_statistics_object_ownercheck(stxoid, GetUserId()))
+ aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_STATISTIC_EXT,
+ NameListToString(stmt->defnames));
+
+ /* Build new tuple. */
+ memset(repl_val, 0, sizeof(repl_val));
+ memset(repl_null, false, sizeof(repl_null));
+ memset(repl_repl, false, sizeof(repl_repl));
+
+ /* replace the stxstattarget column */
+ repl_repl[Anum_pg_statistic_ext_stxstattarget - 1] = true;
+ repl_val[Anum_pg_statistic_ext_stxstattarget - 1] = Int32GetDatum(newtarget);
+
+ newtup = heap_modify_tuple(oldtup, RelationGetDescr(rel),
+ repl_val, repl_null, repl_repl);
+
+ /* Update system catalog. */
+ CatalogTupleUpdate(rel, &newtup->t_self, newtup);
+
+ InvokeObjectPostAlterHook(StatisticExtRelationId, stxoid, 0);
+
+ ObjectAddressSet(address, StatisticExtRelationId, stxoid);
+
+ /*
+ * NOTE: because we only support altering the statistics target, not the
+ * other fields, there is no need to update dependencies.
+ */
+
+ heap_freetuple(newtup);
+ ReleaseSysCache(oldtup);
+
+ table_close(rel, RowExclusiveLock);
+
+ return address;
+}
+
+/*
* Guts of statistics object deletion.
*/
void
diff --git a/src/backend/nodes/copyfuncs.c b/src/backend/nodes/copyfuncs.c
index a2617c7cfd3..3432bb921dd 100644
--- a/src/backend/nodes/copyfuncs.c
+++ b/src/backend/nodes/copyfuncs.c
@@ -3497,6 +3497,18 @@ _copyCreateStatsStmt(const CreateStatsStmt *from)
return newnode;
}
+static AlterStatsStmt *
+_copyAlterStatsStmt(const AlterStatsStmt *from)
+{
+ AlterStatsStmt *newnode = makeNode(AlterStatsStmt);
+
+ COPY_NODE_FIELD(defnames);
+ COPY_SCALAR_FIELD(stxstattarget);
+ COPY_SCALAR_FIELD(missing_ok);
+
+ return newnode;
+}
+
static CreateFunctionStmt *
_copyCreateFunctionStmt(const CreateFunctionStmt *from)
{
@@ -5211,6 +5223,9 @@ copyObjectImpl(const void *from)
case T_CreateStatsStmt:
retval = _copyCreateStatsStmt(from);
break;
+ case T_AlterStatsStmt:
+ retval = _copyAlterStatsStmt(from);
+ break;
case T_CreateFunctionStmt:
retval = _copyCreateFunctionStmt(from);
break;
diff --git a/src/backend/nodes/equalfuncs.c b/src/backend/nodes/equalfuncs.c
index 4f2ebe5118e..18cb0143733 100644
--- a/src/backend/nodes/equalfuncs.c
+++ b/src/backend/nodes/equalfuncs.c
@@ -1366,6 +1366,16 @@ _equalCreateStatsStmt(const CreateStatsStmt *a, const CreateStatsStmt *b)
}
static bool
+_equalAlterStatsStmt(const AlterStatsStmt *a, const AlterStatsStmt *b)
+{
+ COMPARE_NODE_FIELD(defnames);
+ COMPARE_SCALAR_FIELD(stxstattarget);
+ COMPARE_SCALAR_FIELD(missing_ok);
+
+ return true;
+}
+
+static bool
_equalCreateFunctionStmt(const CreateFunctionStmt *a, const CreateFunctionStmt *b)
{
COMPARE_SCALAR_FIELD(is_procedure);
@@ -3309,6 +3319,9 @@ equal(const void *a, const void *b)
case T_CreateStatsStmt:
retval = _equalCreateStatsStmt(a, b);
break;
+ case T_AlterStatsStmt:
+ retval = _equalAlterStatsStmt(a, b);
+ break;
case T_CreateFunctionStmt:
retval = _equalCreateFunctionStmt(a, b);
break;
diff --git a/src/backend/nodes/outfuncs.c b/src/backend/nodes/outfuncs.c
index e6ce8e21101..b0dcd02ff68 100644
--- a/src/backend/nodes/outfuncs.c
+++ b/src/backend/nodes/outfuncs.c
@@ -2669,6 +2669,16 @@ _outCreateStatsStmt(StringInfo str, const CreateStatsStmt *node)
}
static void
+_outAlterStatsStmt(StringInfo str, const AlterStatsStmt *node)
+{
+ WRITE_NODE_TYPE("ALTERSTATSSTMT");
+
+ WRITE_NODE_FIELD(defnames);
+ WRITE_INT_FIELD(stxstattarget);
+ WRITE_BOOL_FIELD(missing_ok);
+}
+
+static void
_outNotifyStmt(StringInfo str, const NotifyStmt *node)
{
WRITE_NODE_TYPE("NOTIFY");
@@ -4130,6 +4140,9 @@ outNode(StringInfo str, const void *obj)
case T_CreateStatsStmt:
_outCreateStatsStmt(str, obj);
break;
+ case T_AlterStatsStmt:
+ _outAlterStatsStmt(str, obj);
+ break;
case T_NotifyStmt:
_outNotifyStmt(str, obj);
break;
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index a954acf509e..3f67aaf30ea 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -252,7 +252,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
AlterOperatorStmt AlterSeqStmt AlterSystemStmt AlterTableStmt
AlterTblSpcStmt AlterExtensionStmt AlterExtensionContentsStmt AlterForeignTableStmt
AlterCompositeTypeStmt AlterUserMappingStmt
- AlterRoleStmt AlterRoleSetStmt AlterPolicyStmt
+ AlterRoleStmt AlterRoleSetStmt AlterPolicyStmt AlterStatsStmt
AlterDefaultPrivilegesStmt DefACLAction
AnalyzeStmt CallStmt ClosePortalStmt ClusterStmt CommentStmt
ConstraintsSetStmt CopyStmt CreateAsStmt CreateCastStmt
@@ -852,6 +852,7 @@ stmt :
| AlterRoleSetStmt
| AlterRoleStmt
| AlterSubscriptionStmt
+ | AlterStatsStmt
| AlterTSConfigurationStmt
| AlterTSDictionaryStmt
| AlterUserMappingStmt
@@ -3984,6 +3985,34 @@ CreateStatsStmt:
}
;
+
+/*****************************************************************************
+ *
+ * QUERY :
+ * ALTER STATISTICS [IF EXISTS] stats_name
+ * SET STATISTICS <SignedIconst>
+ *
+ *****************************************************************************/
+
+AlterStatsStmt:
+ ALTER STATISTICS any_name SET STATISTICS SignedIconst
+ {
+ AlterStatsStmt *n = makeNode(AlterStatsStmt);
+ n->defnames = $3;
+ n->missing_ok = false;
+ n->stxstattarget = $6;
+ $$ = (Node *)n;
+ }
+ | ALTER STATISTICS IF_P EXISTS any_name SET STATISTICS SignedIconst
+ {
+ AlterStatsStmt *n = makeNode(AlterStatsStmt);
+ n->defnames = $5;
+ n->missing_ok = true;
+ n->stxstattarget = $8;
+ $$ = (Node *)n;
+ }
+ ;
+
/*****************************************************************************
*
* QUERY :
diff --git a/src/backend/statistics/extended_stats.c b/src/backend/statistics/extended_stats.c
index dd29b2f9fff..207ee3160ef 100644
--- a/src/backend/statistics/extended_stats.c
+++ b/src/backend/statistics/extended_stats.c
@@ -62,6 +62,7 @@ typedef struct StatExtEntry
char *name; /* statistics object's name */
Bitmapset *columns; /* attribute numbers covered by the object */
List *types; /* 'char' list of enabled statistic kinds */
+ int stattarget; /* statistics target (-1 for default) */
} StatExtEntry;
@@ -71,7 +72,8 @@ static VacAttrStats **lookup_var_attr_stats(Relation rel, Bitmapset *attrs,
static void statext_store(Oid relid,
MVNDistinct *ndistinct, MVDependencies *dependencies,
MCVList *mcv, VacAttrStats **stats);
-
+static int statext_compute_stattarget(int stattarget,
+ int natts, VacAttrStats **stats);
/*
* Compute requested extended stats, using the rows sampled for the plain
@@ -107,6 +109,7 @@ BuildRelationExtStatistics(Relation onerel, double totalrows,
MCVList *mcv = NULL;
VacAttrStats **stats;
ListCell *lc2;
+ int stattarget;
/*
* Check if we can build these stats based on the column analyzed. If
@@ -131,6 +134,19 @@ BuildRelationExtStatistics(Relation onerel, double totalrows,
Assert(bms_num_members(stat->columns) >= 2 &&
bms_num_members(stat->columns) <= STATS_MAX_DIMENSIONS);
+ /* compute statistics target for this statistics */
+ stattarget = statext_compute_stattarget(stat->stattarget,
+ bms_num_members(stat->columns),
+ stats);
+
+ /*
+ * Don't rebuild statistics objects with statistics target set to 0 (we
+ * just leave the existing values around, just like we do for regular
+ * per-column statistics).
+ */
+ if (stattarget == 0)
+ continue;
+
/* compute statistic of each requested type */
foreach(lc2, stat->types)
{
@@ -144,7 +160,7 @@ BuildRelationExtStatistics(Relation onerel, double totalrows,
stat->columns, stats);
else if (t == STATS_EXT_MCV)
mcv = statext_mcv_build(numrows, rows, stat->columns, stats,
- totalrows);
+ totalrows, stattarget);
}
/* store the statistics in the catalog */
@@ -158,6 +174,135 @@ BuildRelationExtStatistics(Relation onerel, double totalrows,
}
/*
+ * ComputeExtStatisticsRows
+ * Compute number of rows required by extended statistics on a table.
+ *
+ * Computes number of rows we need to sample to build extended statistics on a
+ * table. This only looks at statistics we can actually build - for example
+ * when analyzing only some of the columns, this will skip statistics objects
+ * that would require additional columns.
+ *
+ * See statext_compute_stattarget for details about how we compute statistics
+ * target for a statistics objects (from the object target, attribute targets
+ * and default statistics target).
+ */
+int
+ComputeExtStatisticsRows(Relation onerel,
+ int natts, VacAttrStats **vacattrstats)
+{
+ Relation pg_stext;
+ ListCell *lc;
+ List *lstats;
+ MemoryContext cxt;
+ MemoryContext oldcxt;
+ int result = 0;
+
+ cxt = AllocSetContextCreate(CurrentMemoryContext,
+ "ComputeExtStatisticsRows",
+ ALLOCSET_DEFAULT_SIZES);
+ oldcxt = MemoryContextSwitchTo(cxt);
+
+ pg_stext = table_open(StatisticExtRelationId, RowExclusiveLock);
+ lstats = fetch_statentries_for_relation(pg_stext, RelationGetRelid(onerel));
+
+ foreach(lc, lstats)
+ {
+ StatExtEntry *stat = (StatExtEntry *) lfirst(lc);
+ int stattarget = stat->stattarget;
+ VacAttrStats **stats;
+ int nattrs = bms_num_members(stat->columns);
+
+ /*
+ * Check if we can build this statistics object based on the columns
+ * analyzed. If not, ignore it (don't report anything, we'll do that
+ * during the actual build BuildRelationExtStatistics).
+ */
+ stats = lookup_var_attr_stats(onerel, stat->columns,
+ natts, vacattrstats);
+
+ if (!stats)
+ continue;
+
+ /*
+ * Compute statistics target, based on what's set for the statistic
+ * object itself, and for its attributes.
+ */
+ stattarget = statext_compute_stattarget(stat->stattarget,
+ nattrs, stats);
+
+ /* Use the largest value for all statistics objects. */
+ if (stattarget > result)
+ result = stattarget;
+ }
+
+ table_close(pg_stext, RowExclusiveLock);
+
+ MemoryContextSwitchTo(oldcxt);
+ MemoryContextDelete(cxt);
+
+ /* compute sample size based on the statistics target */
+ return (300 * result);
+}
+
+/*
+ * statext_compute_stattarget
+ * compute statistics target for an extended statistic
+ *
+ * When computing target for extended statistics objects, we consider three
+ * places where the target may be set - the statistics object itself,
+ * attributes the statistics is defined on, and then the default statistics
+ * target.
+ *
+ * First we look at what's set for the statistics object itself, using the
+ * ALTER STATISTICS ... SET STATISTICS command. If we find a valid value
+ * there (i.e. not -1) we're done. Otherwise we look at targets set for any
+ * of the attributes the statistic is defined on, and if there are columns
+ * with defined target, we use the maximum value. We do this mostly for
+ * backwards compatibility, because this is what we did before having
+ * statistics target for extended statistics.
+ *
+ * And finally, if we still don't have a statistics target, we use the value
+ * set in default_statistics_target.
+ */
+static int
+statext_compute_stattarget(int stattarget, int nattrs, VacAttrStats **stats)
+{
+ int i;
+
+ /*
+ * If there's statistics target set for the statistics object, use it.
+ * It may be set to 0 which disables building of that statistic.
+ */
+ if (stattarget >= 0)
+ return stattarget;
+
+ /*
+ * The target for the statistics object is set to -1, in which case we
+ * look at the maximum target set for any of the attributes the object
+ * is defined on.
+ */
+ for (i = 0; i < nattrs; i++)
+ {
+ /* keep the maximmum statistics target */
+ if (stats[i]->attr->attstattarget > stattarget)
+ stattarget = stats[i]->attr->attstattarget;
+ }
+
+ /*
+ * If the value is still negative (so neither the statistics object nor
+ * any of the columns have custom statistics target set), use the global
+ * default target.
+ */
+ if (stattarget < 0)
+ stattarget = default_statistics_target;
+
+ /* As this point we should have a valid statistics target. */
+ Assert((stattarget >= 0) && (stattarget <= 10000));
+
+ return stattarget;
+}
+
+/*
* statext_is_kind_built
* Is this stat kind built in the given pg_statistic_ext_data tuple?
*/
@@ -225,6 +370,7 @@ fetch_statentries_for_relation(Relation pg_statext, Oid relid)
entry->statOid = staForm->oid;
entry->schema = get_namespace_name(staForm->stxnamespace);
entry->name = pstrdup(NameStr(staForm->stxname));
+ entry->stattarget = staForm->stxstattarget;
for (i = 0; i < staForm->stxkeys.dim1; i++)
{
entry->columns = bms_add_member(entry->columns,
diff --git a/src/backend/statistics/mcv.c b/src/backend/statistics/mcv.c
index bae6f219684..ee35f6afc56 100644
--- a/src/backend/statistics/mcv.c
+++ b/src/backend/statistics/mcv.c
@@ -181,7 +181,7 @@ get_mincount_for_mcv_list(int samplerows, double totalrows)
*/
MCVList *
statext_mcv_build(int numrows, HeapTuple *rows, Bitmapset *attrs,
- VacAttrStats **stats, double totalrows)
+ VacAttrStats **stats, double totalrows, int stattarget)
{
int i,
numattrs,
@@ -210,15 +210,12 @@ statext_mcv_build(int numrows, HeapTuple *rows, Bitmapset *attrs,
groups = build_distinct_groups(nitems, items, mss, &ngroups);
/*
- * Maximum number of MCV items to store, based on the attribute with the
- * largest stats target (and the number of groups we have available).
+ * Maximum number of MCV items to store, based on the statistics target
+ * we computed for the statistics object (from target set for the object
+ * itself, attributes and the system default). In any case, we can't keep
+ * more groups than we have available.
*/
- nitems = stats[0]->attr->attstattarget;
- for (i = 1; i < numattrs; i++)
- {
- if (stats[i]->attr->attstattarget > nitems)
- nitems = stats[i]->attr->attstattarget;
- }
+ nitems = stattarget;
if (nitems > ngroups)
nitems = ngroups;
diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c
index 7f6f0b6498f..c6faa6619d2 100644
--- a/src/backend/tcop/utility.c
+++ b/src/backend/tcop/utility.c
@@ -1688,6 +1688,10 @@ ProcessUtilitySlow(ParseState *pstate,
address = CreateStatistics((CreateStatsStmt *) parsetree);
break;
+ case T_AlterStatsStmt:
+ address = AlterStatistics((AlterStatsStmt *) parsetree);
+ break;
+
case T_AlterCollationStmt:
address = AlterCollation((AlterCollationStmt *) parsetree);
break;
@@ -2805,6 +2809,10 @@ CreateCommandTag(Node *parsetree)
tag = "CREATE STATISTICS";
break;
+ case T_AlterStatsStmt:
+ tag = "ALTER STATISTICS";
+ break;
+
case T_DeallocateStmt:
{
DeallocateStmt *stmt = (DeallocateStmt *) parsetree;
@@ -3393,6 +3401,10 @@ GetCommandLogLevel(Node *parsetree)
lev = LOGSTMT_DDL;
break;
+ case T_AlterStatsStmt:
+ lev = LOGSTMT_DDL;
+ break;
+
case T_AlterCollationStmt:
lev = LOGSTMT_DDL;
break;
generated by cgit v1.2.3 (git 2.25.1) at 2025-08-05 22:41:38 +0000