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-rw-r--r--src/backend/statistics/dependencies.c26
-rw-r--r--src/backend/statistics/extended_stats.c40
-rw-r--r--src/include/statistics/statistics.h5
-rw-r--r--src/test/regress/expected/stats_ext.out25
-rw-r--r--src/test/regress/sql/stats_ext.sql9
5 files changed, 81 insertions, 24 deletions
diff --git a/src/backend/statistics/dependencies.c b/src/backend/statistics/dependencies.c
index 9493b2d5397..ce31c959a9e 100644
--- a/src/backend/statistics/dependencies.c
+++ b/src/backend/statistics/dependencies.c
@@ -951,14 +951,14 @@ dependencies_clauselist_selectivity(PlannerInfo *root,
Bitmapset *clauses_attnums = NULL;
StatisticExtInfo *stat;
MVDependencies *dependencies;
- AttrNumber *list_attnums;
+ Bitmapset **list_attnums;
int listidx;
/* check if there's any stats that might be useful for us. */
if (!has_stats_of_kind(rel->statlist, STATS_EXT_DEPENDENCIES))
return 1.0;
- list_attnums = (AttrNumber *) palloc(sizeof(AttrNumber) *
+ list_attnums = (Bitmapset **) palloc(sizeof(Bitmapset *) *
list_length(clauses));
/*
@@ -981,11 +981,11 @@ dependencies_clauselist_selectivity(PlannerInfo *root,
if (!bms_is_member(listidx, *estimatedclauses) &&
dependency_is_compatible_clause(clause, rel->relid, &attnum))
{
- list_attnums[listidx] = attnum;
+ list_attnums[listidx] = bms_make_singleton(attnum);
clauses_attnums = bms_add_member(clauses_attnums, attnum);
}
else
- list_attnums[listidx] = InvalidAttrNumber;
+ list_attnums[listidx] = NULL;
listidx++;
}
@@ -1002,8 +1002,8 @@ dependencies_clauselist_selectivity(PlannerInfo *root,
}
/* find the best suited statistics object for these attnums */
- stat = choose_best_statistics(rel->statlist, clauses_attnums,
- STATS_EXT_DEPENDENCIES);
+ stat = choose_best_statistics(rel->statlist, STATS_EXT_DEPENDENCIES,
+ list_attnums, list_length(clauses));
/* if no matching stats could be found then we've nothing to do */
if (!stat)
@@ -1043,16 +1043,22 @@ dependencies_clauselist_selectivity(PlannerInfo *root,
foreach(l, clauses)
{
Node *clause;
+ AttrNumber attnum;
listidx++;
/*
* Skip incompatible clauses, and ones we've already estimated on.
*/
- if (list_attnums[listidx] == InvalidAttrNumber)
+ if (!list_attnums[listidx])
continue;
/*
+ * We expect the bitmaps ton contain a single attribute number.
+ */
+ attnum = bms_singleton_member(list_attnums[listidx]);
+
+ /*
* Technically we could find more than one clause for a given
* attnum. Since these clauses must be equality clauses, we choose
* to only take the selectivity estimate from the final clause in
@@ -1061,8 +1067,7 @@ dependencies_clauselist_selectivity(PlannerInfo *root,
* anyway. If it happens to be compared to the same Const, then
* ignoring the additional clause is just the thing to do.
*/
- if (dependency_implies_attribute(dependency,
- list_attnums[listidx]))
+ if (dependency_implies_attribute(dependency, attnum))
{
clause = (Node *) lfirst(l);
@@ -1077,8 +1082,7 @@ dependencies_clauselist_selectivity(PlannerInfo *root,
* We'll want to ignore this when looking for the next
* strongest dependency above.
*/
- clauses_attnums = bms_del_member(clauses_attnums,
- list_attnums[listidx]);
+ clauses_attnums = bms_del_member(clauses_attnums, attnum);
}
}
diff --git a/src/backend/statistics/extended_stats.c b/src/backend/statistics/extended_stats.c
index 207ee3160ef..6299011ca66 100644
--- a/src/backend/statistics/extended_stats.c
+++ b/src/backend/statistics/extended_stats.c
@@ -844,15 +844,20 @@ has_stats_of_kind(List *stats, char requiredkind)
* there's no match.
*
* The current selection criteria is very simple - we choose the statistics
- * object referencing the most of the requested attributes, breaking ties
- * in favor of objects with fewer keys overall.
+ * object referencing the most attributes in covered (and still unestimated
+ * clauses), breaking ties in favor of objects with fewer keys overall.
+ *
+ * The clause_attnums is an array of bitmaps, storing attnums for individual
+ * clauses. A NULL element means the clause is either incompatible or already
+ * estimated.
*
* XXX If multiple statistics objects tie on both criteria, then which object
* is chosen depends on the order that they appear in the stats list. Perhaps
* further tiebreakers are needed.
*/
StatisticExtInfo *
-choose_best_statistics(List *stats, Bitmapset *attnums, char requiredkind)
+choose_best_statistics(List *stats, char requiredkind,
+ Bitmapset **clause_attnums, int nclauses)
{
ListCell *lc;
StatisticExtInfo *best_match = NULL;
@@ -861,17 +866,33 @@ choose_best_statistics(List *stats, Bitmapset *attnums, char requiredkind)
foreach(lc, stats)
{
+ int i;
StatisticExtInfo *info = (StatisticExtInfo *) lfirst(lc);
+ Bitmapset *matched = NULL;
int num_matched;
int numkeys;
- Bitmapset *matched;
/* skip statistics that are not of the correct type */
if (info->kind != requiredkind)
continue;
- /* determine how many attributes of these stats can be matched to */
- matched = bms_intersect(attnums, info->keys);
+ /*
+ * Collect attributes in remaining (unestimated) clauses fully covered
+ * by this statistic object.
+ */
+ for (i = 0; i < nclauses; i++)
+ {
+ /* ignore incompatible/estimated clauses */
+ if (!clause_attnums[i])
+ continue;
+
+ /* ignore clauses that are not covered by this object */
+ if (!bms_is_subset(clause_attnums[i], info->keys))
+ continue;
+
+ matched = bms_add_members(matched, clause_attnums[i]);
+ }
+
num_matched = bms_num_members(matched);
bms_free(matched);
@@ -1233,12 +1254,9 @@ statext_mcv_clauselist_selectivity(PlannerInfo *root, List *clauses, int varReli
listidx++;
}
- /* We need at least two attributes for multivariate statistics. */
- if (bms_membership(clauses_attnums) != BMS_MULTIPLE)
- return 1.0;
-
/* find the best suited statistics object for these attnums */
- stat = choose_best_statistics(rel->statlist, clauses_attnums, STATS_EXT_MCV);
+ stat = choose_best_statistics(rel->statlist, STATS_EXT_MCV,
+ list_attnums, list_length(clauses));
/* if no matching stats could be found then we've nothing to do */
if (!stat)
diff --git a/src/include/statistics/statistics.h b/src/include/statistics/statistics.h
index 588b6738b2a..6b71569f137 100644
--- a/src/include/statistics/statistics.h
+++ b/src/include/statistics/statistics.h
@@ -118,7 +118,8 @@ extern Selectivity statext_clauselist_selectivity(PlannerInfo *root,
RelOptInfo *rel,
Bitmapset **estimatedclauses);
extern bool has_stats_of_kind(List *stats, char requiredkind);
-extern StatisticExtInfo *choose_best_statistics(List *stats,
- Bitmapset *attnums, char requiredkind);
+extern StatisticExtInfo *choose_best_statistics(List *stats, char requiredkind,
+ Bitmapset **clause_attnums,
+ int nclauses);
#endif /* STATISTICS_H */
diff --git a/src/test/regress/expected/stats_ext.out b/src/test/regress/expected/stats_ext.out
index dfbc41c390d..6fb1aeb596a 100644
--- a/src/test/regress/expected/stats_ext.out
+++ b/src/test/regress/expected/stats_ext.out
@@ -534,6 +534,18 @@ SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a <= 4 AND b <
1 | 50
(1 row)
+SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a = 1 OR b = ''1'' OR c = 1');
+ estimated | actual
+-----------+--------
+ 343 | 200
+(1 row)
+
+SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a = 1 OR b = ''1'' OR c = 1 OR d IS NOT NULL');
+ estimated | actual
+-----------+--------
+ 343 | 200
+(1 row)
+
-- create statistics
CREATE STATISTICS mcv_lists_stats (mcv) ON a, b, c FROM mcv_lists;
ANALYZE mcv_lists;
@@ -573,6 +585,19 @@ SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a <= 4 AND b <
50 | 50
(1 row)
+SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a = 1 OR b = ''1'' OR c = 1');
+ estimated | actual
+-----------+--------
+ 200 | 200
+(1 row)
+
+-- we can't use the statistic for OR clauses that are not fully covered (missing 'd' attribute)
+SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a = 1 OR b = ''1'' OR c = 1 OR d IS NOT NULL');
+ estimated | actual
+-----------+--------
+ 343 | 200
+(1 row)
+
-- check change of unrelated column type does not reset the MCV statistics
ALTER TABLE mcv_lists ALTER COLUMN d TYPE VARCHAR(64);
SELECT d.stxdmcv IS NOT NULL
diff --git a/src/test/regress/sql/stats_ext.sql b/src/test/regress/sql/stats_ext.sql
index 6237fb25c20..4999d89c8cd 100644
--- a/src/test/regress/sql/stats_ext.sql
+++ b/src/test/regress/sql/stats_ext.sql
@@ -342,6 +342,10 @@ SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a < 5 AND b <
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a <= 4 AND b <= ''0'' AND c <= 4');
+SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a = 1 OR b = ''1'' OR c = 1');
+
+SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a = 1 OR b = ''1'' OR c = 1 OR d IS NOT NULL');
+
-- create statistics
CREATE STATISTICS mcv_lists_stats (mcv) ON a, b, c FROM mcv_lists;
@@ -359,6 +363,11 @@ SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a < 5 AND b <
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a <= 4 AND b <= ''0'' AND c <= 4');
+SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a = 1 OR b = ''1'' OR c = 1');
+
+-- we can't use the statistic for OR clauses that are not fully covered (missing 'd' attribute)
+SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a = 1 OR b = ''1'' OR c = 1 OR d IS NOT NULL');
+
-- check change of unrelated column type does not reset the MCV statistics
ALTER TABLE mcv_lists ALTER COLUMN d TYPE VARCHAR(64);
generated by cgit v1.2.3 (git 2.25.1) at 2025-06-12 20:06:57 +0000