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Add stxdinherit flag to pg_statistic_ext_data 

Add pg_statistic_ext_data.stxdinherit flag, so that for each extended
statistics definition we can store two versions of data - one for the
relation alone, one for the whole inheritance tree. This is analogous to
pg_statistic.stainherit, but we failed to include such flag in catalogs
for extended statistics, and we had to work around it (see commits
859b3003de, 36c4bc6e72 and 20b9fa308e).

This changes the relationship between the two catalogs storing extended
statistics objects (pg_statistic_ext and pg_statistic_ext_data). Until
now, there was a simple 1:1 mapping - for each definition there was one
pg_statistic_ext_data row, and this row was inserted while creating the
statistics (and then updated during ANALYZE). With the stxdinherit flag,
we don't know how many rows there will be (child relations may be added
after the statistics object is defined), so there may be up to two rows.

We could make CREATE STATISTICS to always create both rows, but that
seems wasteful - without partitioning we only need stxdinherit=false
rows, and declaratively partitioned tables need only stxdinherit=true.
So we no longer initialize pg_statistic_ext_data in CREATE STATISTICS,
and instead make that a responsibility of ANALYZE. Which is what we do
for regular statistics too.

Patch by me, with extensive improvements and fixes by Justin Pryzby.

Author: Tomas Vondra, Justin Pryzby
Reviewed-by: Tomas Vondra, Justin Pryzby
Discussion: https://postgr.es/m/20210923212624.GI831%40telsasoft.com
This commit is contained in:
Tomas Vondra 2022-01-16 13:37:56 +01:00
parent e701bdd2f0
commit 269b532aef
19 changed files with 251 additions and 236 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

23
doc/src/sgml/catalogs.sgml
View File

@ -7521,6 +7521,19 @@ SCRAM-SHA-256$<replaceable>&lt;iteration count&gt;</replaceable>:<replaceable>&l
created with <link linkend="sql-createstatistics"><command>CREATE STATISTICS</command></link>.
</para>
<para>
Normally there is one entry, with <structfield>stxdinherit</structfield> =
<literal>false</literal>, for each statistics object that has been analyzed.
If the table has inheritance children, a second entry with
<structfield>stxdinherit</structfield> = <literal>true</literal> is also created.
This row represents the statistics object over the inheritance tree, i.e.,
statistics for the data you'd see with
<literal>SELECT * FROM <replaceable>table</replaceable>*</literal>,
whereas the <structfield>stxdinherit</structfield> = <literal>false</literal> row
represents the results of
<literal>SELECT * FROM ONLY <replaceable>table</replaceable></literal>.
</para>
<para>
Like <link linkend="catalog-pg-statistic"><structname>pg_statistic</structname></link>,
<structname>pg_statistic_ext_data</structname> should not be
@ -7560,6 +7573,16 @@ SCRAM-SHA-256$<replaceable>&lt;iteration count&gt;</replaceable>:<replaceable>&l
</para></entry>
</row>
<row>
<entry role="catalog_table_entry"><para role="column_definition">
<structfield>stxdinherit</structfield> <type>bool</type>
</para>
<para>
If true, the stats include inheritance child columns, not just the
values in the specified relation
</para></entry>
</row>
<row>
<entry role="catalog_table_entry"><para role="column_definition">
<structfield>stxdndistinct</structfield> <type>pg_ndistinct</type>

2
src/backend/catalog/system_views.sql
View File

@ -266,6 +266,7 @@ CREATE VIEW pg_stats_ext WITH (security_barrier) AS
) AS attnames,
pg_get_statisticsobjdef_expressions(s.oid) as exprs,
s.stxkind AS kinds,
sd.stxdinherit AS inherited,
sd.stxdndistinct AS n_distinct,
sd.stxddependencies AS dependencies,
m.most_common_vals,
@ -298,6 +299,7 @@ CREATE VIEW pg_stats_ext_exprs WITH (security_barrier) AS
s.stxname AS statistics_name,
pg_get_userbyid(s.stxowner) AS statistics_owner,
stat.expr,
sd.stxdinherit AS inherited,
(stat.a).stanullfrac AS null_frac,
(stat.a).stawidth AS avg_width,
(stat.a).stadistinct AS n_distinct,

28
src/backend/commands/analyze.c
View File

@ -549,7 +549,6 @@ do_analyze_rel(Relation onerel, VacuumParams *params,
{
MemoryContext col_context,
old_context;
bool build_ext_stats;
pgstat_progress_update_param(PROGRESS_ANALYZE_PHASE,
PROGRESS_ANALYZE_PHASE_COMPUTE_STATS);
@ -613,30 +612,9 @@ do_analyze_rel(Relation onerel, VacuumParams *params,
thisdata->attr_cnt, thisdata->vacattrstats);
}
/*
* Should we build extended statistics for this relation?
*
* The extended statistics catalog does not include an inheritance
* flag, so we can't store statistics built both with and without
* data from child relations. We can store just one set of statistics
* per relation. For plain relations that's fine, but for inheritance
* trees we have to pick whether to store statistics for just the
* one relation or the whole tree. For plain inheritance we store
* the (!inh) version, mostly for backwards compatibility reasons.
* For partitioned tables that's pointless (the non-leaf tables are
* always empty), so we store stats representing the whole tree.
*/
build_ext_stats = (onerel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE) ? inh : (!inh);
/*
* Build extended statistics (if there are any).
*
* For now we only build extended statistics on individual relations,
* not for relations representing inheritance trees.
*/
if (build_ext_stats)
BuildRelationExtStatistics(onerel, totalrows, numrows, rows,
attr_cnt, vacattrstats);
/* Build extended statistics (if there are any). */
BuildRelationExtStatistics(onerel, inh, totalrows, numrows, rows,
attr_cnt, vacattrstats);
}
pgstat_progress_update_param(PROGRESS_ANALYZE_PHASE,

72
src/backend/commands/statscmds.c
View File

@ -75,13 +75,10 @@ CreateStatistics(CreateStatsStmt *stmt)
HeapTuple htup;
Datum values[Natts_pg_statistic_ext];
bool nulls[Natts_pg_statistic_ext];
Datum datavalues[Natts_pg_statistic_ext_data];
bool datanulls[Natts_pg_statistic_ext_data];
int2vector *stxkeys;
List *stxexprs = NIL;
Datum exprsDatum;
Relation statrel;
Relation datarel;
Relation rel = NULL;
Oid relid;
ObjectAddress parentobject,
@ -514,28 +511,10 @@ CreateStatistics(CreateStatsStmt *stmt)
relation_close(statrel, RowExclusiveLock);
/*
* Also build the pg_statistic_ext_data tuple, to hold the actual
* statistics data.
* We used to create the pg_statistic_ext_data tuple too, but it's not clear
* what value should the stxdinherit flag have (it depends on whether the rel
* is partitioned, contains data, etc.)
*/
datarel = table_open(StatisticExtDataRelationId, RowExclusiveLock);
memset(datavalues, 0, sizeof(datavalues));
memset(datanulls, false, sizeof(datanulls));
datavalues[Anum_pg_statistic_ext_data_stxoid - 1] = ObjectIdGetDatum(statoid);
/* no statistics built yet */
datanulls[Anum_pg_statistic_ext_data_stxdndistinct - 1] = true;
datanulls[Anum_pg_statistic_ext_data_stxddependencies - 1] = true;
datanulls[Anum_pg_statistic_ext_data_stxdmcv - 1] = true;
datanulls[Anum_pg_statistic_ext_data_stxdexpr - 1] = true;
/* insert it into pg_statistic_ext_data */
htup = heap_form_tuple(datarel->rd_att, datavalues, datanulls);
CatalogTupleInsert(datarel, htup);
heap_freetuple(htup);
relation_close(datarel, RowExclusiveLock);
InvokeObjectPostCreateHook(StatisticExtRelationId, statoid, 0);
@ -716,6 +695,32 @@ AlterStatistics(AlterStatsStmt *stmt)
return address;
}
/*
* Delete entry in pg_statistic_ext_data catalog. We don't know if the row
* exists, so don't error out.
*/
void
RemoveStatisticsDataById(Oid statsOid, bool inh)
{
Relation relation;
HeapTuple tup;
relation = table_open(StatisticExtDataRelationId, RowExclusiveLock);
tup = SearchSysCache2(STATEXTDATASTXOID, ObjectIdGetDatum(statsOid),
BoolGetDatum(inh));
/* We don't know if the data row for inh value exists. */
if (HeapTupleIsValid(tup))
{
CatalogTupleDelete(relation, &tup->t_self);
ReleaseSysCache(tup);
}
table_close(relation, RowExclusiveLock);
}
/*
* Guts of statistics object deletion.
*/
@ -728,21 +733,12 @@ RemoveStatisticsById(Oid statsOid)
Oid relid;
/*
* First delete the pg_statistic_ext_data tuple holding the actual
* statistical data.
* First delete the pg_statistic_ext_data tuples holding the actual
* statistical data. There might be data with/without inheritance, so
* attempt deleting both.
*/
relation = table_open(StatisticExtDataRelationId, RowExclusiveLock);
tup = SearchSysCache1(STATEXTDATASTXOID, ObjectIdGetDatum(statsOid));
if (!HeapTupleIsValid(tup)) /* should not happen */
elog(ERROR, "cache lookup failed for statistics data %u", statsOid);
CatalogTupleDelete(relation, &tup->t_self);
ReleaseSysCache(tup);
table_close(relation, RowExclusiveLock);
RemoveStatisticsDataById(statsOid, true);
RemoveStatisticsDataById(statsOid, false);
/*
* Delete the pg_statistic_ext tuple. Also send out a cache inval on the

146
src/backend/optimizer/util/plancat.c
View File

@ -30,6 +30,7 @@
#include "catalog/pg_am.h"
#include "catalog/pg_proc.h"
#include "catalog/pg_statistic_ext.h"
#include "catalog/pg_statistic_ext_data.h"
#include "foreign/fdwapi.h"
#include "miscadmin.h"
#include "nodes/makefuncs.h"
@ -1276,6 +1277,87 @@ get_relation_constraints(PlannerInfo *root,
return result;
}
/*
* Try loading data for the statistics object.
*
* We don't know if the data (specified by statOid and inh value) exist.
* The result is stored in stainfos list.
*/
static void
get_relation_statistics_worker(List **stainfos, RelOptInfo *rel,
Oid statOid, bool inh,
Bitmapset *keys, List *exprs)
{
Form_pg_statistic_ext_data dataForm;
HeapTuple dtup;
dtup = SearchSysCache2(STATEXTDATASTXOID,
ObjectIdGetDatum(statOid), BoolGetDatum(inh));
if (!HeapTupleIsValid(dtup))
return;
dataForm = (Form_pg_statistic_ext_data) GETSTRUCT(dtup);
/* add one StatisticExtInfo for each kind built */
if (statext_is_kind_built(dtup, STATS_EXT_NDISTINCT))
{
StatisticExtInfo *info = makeNode(StatisticExtInfo);
info->statOid = statOid;
info->inherit = dataForm->stxdinherit;
info->rel = rel;
info->kind = STATS_EXT_NDISTINCT;
info->keys = bms_copy(keys);
info->exprs = exprs;
*stainfos = lappend(*stainfos, info);
}
if (statext_is_kind_built(dtup, STATS_EXT_DEPENDENCIES))
{
StatisticExtInfo *info = makeNode(StatisticExtInfo);
info->statOid = statOid;
info->inherit = dataForm->stxdinherit;
info->rel = rel;
info->kind = STATS_EXT_DEPENDENCIES;
info->keys = bms_copy(keys);
info->exprs = exprs;
*stainfos = lappend(*stainfos, info);
}
if (statext_is_kind_built(dtup, STATS_EXT_MCV))
{
StatisticExtInfo *info = makeNode(StatisticExtInfo);
info->statOid = statOid;
info->inherit = dataForm->stxdinherit;
info->rel = rel;
info->kind = STATS_EXT_MCV;
info->keys = bms_copy(keys);
info->exprs = exprs;
*stainfos = lappend(*stainfos, info);
}
if (statext_is_kind_built(dtup, STATS_EXT_EXPRESSIONS))
{
StatisticExtInfo *info = makeNode(StatisticExtInfo);
info->statOid = statOid;
info->inherit = dataForm->stxdinherit;
info->rel = rel;
info->kind = STATS_EXT_EXPRESSIONS;
info->keys = bms_copy(keys);
info->exprs = exprs;
*stainfos = lappend(*stainfos, info);
}
ReleaseSysCache(dtup);
}
/*
* get_relation_statistics
* Retrieve extended statistics defined on the table.
@ -1299,7 +1381,6 @@ get_relation_statistics(RelOptInfo *rel, Relation relation)
Oid statOid = lfirst_oid(l);
Form_pg_statistic_ext staForm;
HeapTuple htup;
HeapTuple dtup;
Bitmapset *keys = NULL;
List *exprs = NIL;
int i;
@ -1309,10 +1390,6 @@ get_relation_statistics(RelOptInfo *rel, Relation relation)
elog(ERROR, "cache lookup failed for statistics object %u", statOid);
staForm = (Form_pg_statistic_ext) GETSTRUCT(htup);
dtup = SearchSysCache1(STATEXTDATASTXOID, ObjectIdGetDatum(statOid));
if (!HeapTupleIsValid(dtup))
elog(ERROR, "cache lookup failed for statistics object %u", statOid);
/*
* First, build the array of columns covered. This is ultimately
* wasted if no stats within the object have actually been built, but
@ -1324,6 +1401,11 @@ get_relation_statistics(RelOptInfo *rel, Relation relation)
/*
* Preprocess expressions (if any). We read the expressions, run them
* through eval_const_expressions, and fix the varnos.
*
* XXX We don't know yet if there are any data for this stats object,
* with either stxdinherit value. But it's reasonable to assume there
* is at least one of those, possibly both. So it's better to process
* keys and expressions here.
*/
{
bool isnull;
@ -1364,61 +1446,13 @@ get_relation_statistics(RelOptInfo *rel, Relation relation)
}
}
/* add one StatisticExtInfo for each kind built */
if (statext_is_kind_built(dtup, STATS_EXT_NDISTINCT))
{
StatisticExtInfo *info = makeNode(StatisticExtInfo);
/* extract statistics for possible values of stxdinherit flag */
info->statOid = statOid;
info->rel = rel;
info->kind = STATS_EXT_NDISTINCT;
info->keys = bms_copy(keys);
info->exprs = exprs;
get_relation_statistics_worker(&stainfos, rel, statOid, true, keys, exprs);
stainfos = lappend(stainfos, info);
}
if (statext_is_kind_built(dtup, STATS_EXT_DEPENDENCIES))
{
StatisticExtInfo *info = makeNode(StatisticExtInfo);
info->statOid = statOid;
info->rel = rel;
info->kind = STATS_EXT_DEPENDENCIES;
info->keys = bms_copy(keys);
info->exprs = exprs;
stainfos = lappend(stainfos, info);
}
if (statext_is_kind_built(dtup, STATS_EXT_MCV))
{
StatisticExtInfo *info = makeNode(StatisticExtInfo);
info->statOid = statOid;
info->rel = rel;
info->kind = STATS_EXT_MCV;
info->keys = bms_copy(keys);
info->exprs = exprs;
stainfos = lappend(stainfos, info);
}
if (statext_is_kind_built(dtup, STATS_EXT_EXPRESSIONS))
{
StatisticExtInfo *info = makeNode(StatisticExtInfo);
info->statOid = statOid;
info->rel = rel;
info->kind = STATS_EXT_EXPRESSIONS;
info->keys = bms_copy(keys);
info->exprs = exprs;
stainfos = lappend(stainfos, info);
}
get_relation_statistics_worker(&stainfos, rel, statOid, false, keys, exprs);
ReleaseSysCache(htup);
ReleaseSysCache(dtup);
bms_free(keys);
}

22
src/backend/statistics/dependencies.c
View File

@ -619,14 +619,16 @@ dependency_is_fully_matched(MVDependency *dependency, Bitmapset *attnums)
* Load the functional dependencies for the indicated pg_statistic_ext tuple
*/
MVDependencies *
statext_dependencies_load(Oid mvoid)
statext_dependencies_load(Oid mvoid, bool inh)
{
MVDependencies *result;
bool isnull;
Datum deps;
HeapTuple htup;
htup = SearchSysCache1(STATEXTDATASTXOID, ObjectIdGetDatum(mvoid));
htup = SearchSysCache2(STATEXTDATASTXOID,
ObjectIdGetDatum(mvoid),
BoolGetDatum(inh));
if (!HeapTupleIsValid(htup))
elog(ERROR, "cache lookup failed for statistics object %u", mvoid);
@ -1417,16 +1419,6 @@ dependencies_clauselist_selectivity(PlannerInfo *root,
Node **unique_exprs;
int unique_exprs_cnt;
/*
* When dealing with regular inheritance trees, ignore extended stats
* (which were built without data from child rels, and thus do not
* represent them). For partitioned tables data there's no data in the
* non-leaf relations, so we build stats only for the inheritance tree.
* So for partitioned tables we do consider extended stats.
*/
if (rte->inh && rte->relkind != RELKIND_PARTITIONED_TABLE)
return 1.0;
/* 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;
@ -1610,6 +1602,10 @@ dependencies_clauselist_selectivity(PlannerInfo *root,
if (stat->kind != STATS_EXT_DEPENDENCIES)
continue;
/* skip statistics with mismatching stxdinherit value */
if (stat->inherit != rte->inh)
continue;
/*
* Count matching attributes - we have to undo the attnum offsets. The
* input attribute numbers are not offset (expressions are not
@ -1656,7 +1652,7 @@ dependencies_clauselist_selectivity(PlannerInfo *root,
if (nmatched + nexprs < 2)
continue;
deps = statext_dependencies_load(stat->statOid);
deps = statext_dependencies_load(stat->statOid, rte->inh);
/*
* The expressions may be represented by different attnums in the

73
src/backend/statistics/extended_stats.c
View File

@ -25,6 +25,7 @@
#include "catalog/pg_statistic_ext.h"
#include "catalog/pg_statistic_ext_data.h"
#include "executor/executor.h"
#include "commands/defrem.h"
#include "commands/progress.h"
#include "miscadmin.h"
#include "nodes/nodeFuncs.h"
@ -78,7 +79,7 @@ typedef struct StatExtEntry
static List *fetch_statentries_for_relation(Relation pg_statext, Oid relid);
static VacAttrStats **lookup_var_attr_stats(Relation rel, Bitmapset *attrs, List *exprs,
int nvacatts, VacAttrStats **vacatts);
static void statext_store(Oid statOid,
static void statext_store(Oid statOid, bool inh,
MVNDistinct *ndistinct, MVDependencies *dependencies,
MCVList *mcv, Datum exprs, VacAttrStats **stats);
static int statext_compute_stattarget(int stattarget,
@ -111,7 +112,7 @@ static StatsBuildData *make_build_data(Relation onerel, StatExtEntry *stat,
* requested stats, and serializes them back into the catalog.
*/
void
BuildRelationExtStatistics(Relation onerel, double totalrows,
BuildRelationExtStatistics(Relation onerel, bool inh, double totalrows,
int numrows, HeapTuple *rows,
int natts, VacAttrStats **vacattrstats)
{
@ -231,7 +232,8 @@ BuildRelationExtStatistics(Relation onerel, double totalrows,
}
/* store the statistics in the catalog */
statext_store(stat->statOid, ndistinct, dependencies, mcv, exprstats, stats);
statext_store(stat->statOid, inh,
ndistinct, dependencies, mcv, exprstats, stats);
/* for reporting progress */
pgstat_progress_update_param(PROGRESS_ANALYZE_EXT_STATS_COMPUTED,
@ -782,23 +784,27 @@ lookup_var_attr_stats(Relation rel, Bitmapset *attrs, List *exprs,
* tuple.
*/
static void
statext_store(Oid statOid,
statext_store(Oid statOid, bool inh,
MVNDistinct *ndistinct, MVDependencies *dependencies,
MCVList *mcv, Datum exprs, VacAttrStats **stats)
{
Relation pg_stextdata;
HeapTuple stup,
oldtup;
HeapTuple stup;
Datum values[Natts_pg_statistic_ext_data];
bool nulls[Natts_pg_statistic_ext_data];
bool replaces[Natts_pg_statistic_ext_data];
pg_stextdata = table_open(StatisticExtDataRelationId, RowExclusiveLock);
memset(nulls, true, sizeof(nulls));
memset(replaces, false, sizeof(replaces));
memset(values, 0, sizeof(values));
/* basic info */
values[Anum_pg_statistic_ext_data_stxoid - 1] = ObjectIdGetDatum(statOid);
nulls[Anum_pg_statistic_ext_data_stxoid - 1] = false;
values[Anum_pg_statistic_ext_data_stxdinherit - 1] = BoolGetDatum(inh);
nulls[Anum_pg_statistic_ext_data_stxdinherit - 1] = false;
/*
* Construct a new pg_statistic_ext_data tuple, replacing the calculated
* stats.
@ -831,25 +837,15 @@ statext_store(Oid statOid,
values[Anum_pg_statistic_ext_data_stxdexpr - 1] = exprs;
}
/* always replace the value (either by bytea or NULL) */
replaces[Anum_pg_statistic_ext_data_stxdndistinct - 1] = true;
replaces[Anum_pg_statistic_ext_data_stxddependencies - 1] = true;
replaces[Anum_pg_statistic_ext_data_stxdmcv - 1] = true;
replaces[Anum_pg_statistic_ext_data_stxdexpr - 1] = true;
/*
* Delete the old tuple if it exists, and insert a new one. It's easier
* than trying to update or insert, based on various conditions.
*/
RemoveStatisticsDataById(statOid, inh);
/* there should already be a pg_statistic_ext_data tuple */
oldtup = SearchSysCache1(STATEXTDATASTXOID, ObjectIdGetDatum(statOid));
if (!HeapTupleIsValid(oldtup))
elog(ERROR, "cache lookup failed for statistics object %u", statOid);
/* replace it */
stup = heap_modify_tuple(oldtup,
RelationGetDescr(pg_stextdata),
values,
nulls,
replaces);
ReleaseSysCache(oldtup);
CatalogTupleUpdate(pg_stextdata, &stup->t_self, stup);
/* form and insert a new tuple */
stup = heap_form_tuple(RelationGetDescr(pg_stextdata), values, nulls);
CatalogTupleInsert(pg_stextdata, stup);
heap_freetuple(stup);
@ -1235,7 +1231,7 @@ stat_covers_expressions(StatisticExtInfo *stat, List *exprs,
* further tiebreakers are needed.
*/
StatisticExtInfo *
choose_best_statistics(List *stats, char requiredkind,
choose_best_statistics(List *stats, char requiredkind, bool inh,
Bitmapset **clause_attnums, List **clause_exprs,
int nclauses)
{
@ -1257,6 +1253,10 @@ choose_best_statistics(List *stats, char requiredkind,
if (info->kind != requiredkind)
continue;
/* skip statistics with mismatching inheritance flag */
if (info->inherit != inh)
continue;
/*
* Collect attributes and expressions in remaining (unestimated)
* clauses fully covered by this statistic object.
@ -1697,16 +1697,6 @@ statext_mcv_clauselist_selectivity(PlannerInfo *root, List *clauses, int varReli
Selectivity sel = (is_or) ? 0.0 : 1.0;
RangeTblEntry *rte = planner_rt_fetch(rel->relid, root);
/*
* When dealing with regular inheritance trees, ignore extended stats
* (which were built without data from child rels, and thus do not
* represent them). For partitioned tables data there's no data in the
* non-leaf relations, so we build stats only for the inheritance tree.
* So for partitioned tables we do consider extended stats.
*/
if (rte->inh && rte->relkind != RELKIND_PARTITIONED_TABLE)
return sel;
/* check if there's any stats that might be useful for us. */
if (!has_stats_of_kind(rel->statlist, STATS_EXT_MCV))
return sel;
@ -1758,7 +1748,7 @@ statext_mcv_clauselist_selectivity(PlannerInfo *root, List *clauses, int varReli
Bitmapset *simple_clauses;
/* find the best suited statistics object for these attnums */
stat = choose_best_statistics(rel->statlist, STATS_EXT_MCV,
stat = choose_best_statistics(rel->statlist, STATS_EXT_MCV, rte->inh,
list_attnums, list_exprs,
list_length(clauses));
@ -1847,7 +1837,7 @@ statext_mcv_clauselist_selectivity(PlannerInfo *root, List *clauses, int varReli
MCVList *mcv_list;
/* Load the MCV list stored in the statistics object */
mcv_list = statext_mcv_load(stat->statOid);
mcv_list = statext_mcv_load(stat->statOid, rte->inh);
/*
* Compute the selectivity of the ORed list of clauses covered by
@ -2408,7 +2398,7 @@ serialize_expr_stats(AnlExprData *exprdata, int nexprs)
* identified by the supplied index.
*/
HeapTuple
statext_expressions_load(Oid stxoid, int idx)
statext_expressions_load(Oid stxoid, bool inh, int idx)
{
bool isnull;
Datum value;
@ -2418,7 +2408,8 @@ statext_expressions_load(Oid stxoid, int idx)
HeapTupleData tmptup;
HeapTuple tup;
htup = SearchSysCache1(STATEXTDATASTXOID, ObjectIdGetDatum(stxoid));
htup = SearchSysCache2(STATEXTDATASTXOID,
ObjectIdGetDatum(stxoid), BoolGetDatum(inh));
if (!HeapTupleIsValid(htup))
elog(ERROR, "cache lookup failed for statistics object %u", stxoid);

8
src/backend/statistics/mcv.c
View File

@ -559,12 +559,13 @@ build_column_frequencies(SortItem *groups, int ngroups,
* Load the MCV list for the indicated pg_statistic_ext tuple.
*/
MCVList *
statext_mcv_load(Oid mvoid)
statext_mcv_load(Oid mvoid, bool inh)
{
MCVList *result;
bool isnull;
Datum mcvlist;
HeapTuple htup = SearchSysCache1(STATEXTDATASTXOID, ObjectIdGetDatum(mvoid));
HeapTuple htup = SearchSysCache2(STATEXTDATASTXOID,
ObjectIdGetDatum(mvoid), BoolGetDatum(inh));
if (!HeapTupleIsValid(htup))
elog(ERROR, "cache lookup failed for statistics object %u", mvoid);
@ -2038,12 +2039,13 @@ mcv_clauselist_selectivity(PlannerInfo *root, StatisticExtInfo *stat,
int i;
MCVList *mcv;
Selectivity s = 0.0;
RangeTblEntry *rte = root->simple_rte_array[rel->relid];
/* match/mismatch bitmap for each MCV item */
bool *matches = NULL;
/* load the MCV list stored in the statistics object */
mcv = statext_mcv_load(stat->statOid);
mcv = statext_mcv_load(stat->statOid, rte->inh);
/* build a match bitmap for the clauses */
matches = mcv_get_match_bitmap(root, clauses, stat->keys, stat->exprs,

5
src/backend/statistics/mvdistinct.c
View File

@ -146,14 +146,15 @@ statext_ndistinct_build(double totalrows, StatsBuildData *data)
* Load the ndistinct value for the indicated pg_statistic_ext tuple
*/
MVNDistinct *
statext_ndistinct_load(Oid mvoid)
statext_ndistinct_load(Oid mvoid, bool inh)
{
MVNDistinct *result;
bool isnull;
Datum ndist;
HeapTuple htup;
htup = SearchSysCache1(STATEXTDATASTXOID, ObjectIdGetDatum(mvoid));
htup = SearchSysCache2(STATEXTDATASTXOID,
ObjectIdGetDatum(mvoid), BoolGetDatum(inh));
if (!HeapTupleIsValid(htup))
elog(ERROR, "cache lookup failed for statistics object %u", mvoid);

37
src/backend/utils/adt/selfuncs.c
View File

@ -3919,17 +3919,6 @@ estimate_multivariate_ndistinct(PlannerInfo *root, RelOptInfo *rel,
if (!rel->statlist)
return false;
/*
* When dealing with regular inheritance trees, ignore extended stats
* (which were built without data from child rels, and thus do not
* represent them). For partitioned tables data there's no data in the
* non-leaf relations, so we build stats only for the inheritance tree.
* So for partitioned tables we do consider extended stats.
*/
rte = planner_rt_fetch(rel->relid, root);
if (rte->inh && rte->relkind != RELKIND_PARTITIONED_TABLE)
return false;
/* look for the ndistinct statistics object matching the most vars */
nmatches_vars = 0; /* we require at least two matches */
nmatches_exprs = 0;
@ -4015,7 +4004,8 @@ estimate_multivariate_ndistinct(PlannerInfo *root, RelOptInfo *rel,
Assert(nmatches_vars + nmatches_exprs > 1);
stats = statext_ndistinct_load(statOid);
rte = planner_rt_fetch(rel->relid, root);
stats = statext_ndistinct_load(statOid, rte->inh);
/*
* If we have a match, search it for the specific item that matches (there
@ -5245,17 +5235,6 @@ examine_variable(PlannerInfo *root, Node *node, int varRelid,
if (vardata->statsTuple)
break;
/*
* When dealing with regular inheritance trees, ignore extended
* stats (which were built without data from child rels, and thus
* do not represent them). For partitioned tables data there's no
* data in the non-leaf relations, so we build stats only for the
* inheritance tree. So for partitioned tables we do consider
* extended stats.
*/
if (rte->inh && rte->relkind != RELKIND_PARTITIONED_TABLE)
break;
/* skip stats without per-expression stats */
if (info->kind != STATS_EXT_EXPRESSIONS)
continue;
@ -5274,22 +5253,16 @@ examine_variable(PlannerInfo *root, Node *node, int varRelid,
/* found a match, see if we can extract pg_statistic row */
if (equal(node, expr))
{
HeapTuple t = statext_expressions_load(info->statOid, pos);
/* Get statistics object's table for permission check */
RangeTblEntry *rte;
Oid userid;
vardata->statsTuple = t;
/*
* XXX Not sure if we should cache the tuple somewhere.
* Now we just create a new copy every time.
*/
vardata->freefunc = ReleaseDummy;
vardata->statsTuple =
statext_expressions_load(info->statOid, rte->inh, pos);
rte = planner_rt_fetch(onerel->relid, root);
Assert(rte->rtekind == RTE_RELATION);
vardata->freefunc = ReleaseDummy;
/*
* Use checkAsUser if it's set, in case we're accessing

6
src/backend/utils/cache/syscache.c vendored
View File

@ -763,11 +763,11 @@ static const struct cachedesc cacheinfo[] = {
32
},
{StatisticExtDataRelationId, /* STATEXTDATASTXOID */
StatisticExtDataStxoidIndexId,
1,
StatisticExtDataStxoidInhIndexId,
2,
{
Anum_pg_statistic_ext_data_stxoid,
0,
Anum_pg_statistic_ext_data_stxdinherit,
0,
0
},

2
src/include/catalog/catversion.h
View File

@ -53,6 +53,6 @@
*/
/* yyyymmddN */
#define CATALOG_VERSION_NO 202201121
#define CATALOG_VERSION_NO 202201161
#endif

4
src/include/catalog/pg_statistic_ext_data.h
View File

@ -32,6 +32,7 @@ CATALOG(pg_statistic_ext_data,3429,StatisticExtDataRelationId)
{
Oid stxoid BKI_LOOKUP(pg_statistic_ext); /* statistics object
* this data is for */
bool stxdinherit; /* true if inheritance children are included */
#ifdef CATALOG_VARLEN /* variable-length fields start here */
@ -53,6 +54,7 @@ typedef FormData_pg_statistic_ext_data * Form_pg_statistic_ext_data;
DECLARE_TOAST(pg_statistic_ext_data, 3430, 3431);
DECLARE_UNIQUE_INDEX_PKEY(pg_statistic_ext_data_stxoid_index, 3433, StatisticExtDataStxoidIndexId, on pg_statistic_ext_data using btree(stxoid oid_ops));
DECLARE_UNIQUE_INDEX_PKEY(pg_statistic_ext_data_stxoid_inh_index, 3433, StatisticExtDataStxoidInhIndexId, on pg_statistic_ext_data using btree(stxoid oid_ops, stxdinherit bool_ops));
#endif /* PG_STATISTIC_EXT_DATA_H */

1
src/include/commands/defrem.h
View File

@ -83,6 +83,7 @@ extern ObjectAddress AlterOperator(AlterOperatorStmt *stmt);
extern ObjectAddress CreateStatistics(CreateStatsStmt *stmt);
extern ObjectAddress AlterStatistics(AlterStatsStmt *stmt);
extern void RemoveStatisticsById(Oid statsOid);
extern void RemoveStatisticsDataById(Oid statsOid, bool inh);
extern Oid StatisticsGetRelation(Oid statId, bool missing_ok);
/* commands/aggregatecmds.c */

1
src/include/nodes/pathnodes.h
View File

@ -934,6 +934,7 @@ typedef struct StatisticExtInfo
NodeTag type;
Oid statOid; /* OID of the statistics row */
bool inherit; /* includes child relations */
RelOptInfo *rel; /* back-link to statistic's table */
char kind; /* statistics kind of this entry */
Bitmapset *keys; /* attnums of the columns covered */

11
src/include/statistics/statistics.h
View File

@ -94,11 +94,11 @@ typedef struct MCVList
MCVItem items[FLEXIBLE_ARRAY_MEMBER]; /* array of MCV items */
} MCVList;
extern MVNDistinct *statext_ndistinct_load(Oid mvoid);
extern MVDependencies *statext_dependencies_load(Oid mvoid);
extern MCVList *statext_mcv_load(Oid mvoid);
extern MVNDistinct *statext_ndistinct_load(Oid mvoid, bool inh);
extern MVDependencies *statext_dependencies_load(Oid mvoid, bool inh);
extern MCVList *statext_mcv_load(Oid mvoid, bool inh);
extern void BuildRelationExtStatistics(Relation onerel, double totalrows,
extern void BuildRelationExtStatistics(Relation onerel, bool inh, double totalrows,
int numrows, HeapTuple *rows,
int natts, VacAttrStats **vacattrstats);
extern int ComputeExtStatisticsRows(Relation onerel,
@ -121,9 +121,10 @@ extern Selectivity statext_clauselist_selectivity(PlannerInfo *root,
bool is_or);
extern bool has_stats_of_kind(List *stats, char requiredkind);
extern StatisticExtInfo *choose_best_statistics(List *stats, char requiredkind,
bool inh,
Bitmapset **clause_attnums,
List **clause_exprs,
int nclauses);
extern HeapTuple statext_expressions_load(Oid stxoid, int idx);
extern HeapTuple statext_expressions_load(Oid stxoid, bool inh, int idx);
#endif /* STATISTICS_H */

2
src/test/regress/expected/rules.out
View File

@ -2443,6 +2443,7 @@ pg_stats_ext| SELECT cn.nspname AS schemaname,
JOIN pg_attribute a ON (((a.attrelid = s.stxrelid) AND (a.attnum = k.k))))) AS attnames,
pg_get_statisticsobjdef_expressions(s.oid) AS exprs,
s.stxkind AS kinds,
sd.stxdinherit AS inherited,
sd.stxdndistinct AS n_distinct,
sd.stxddependencies AS dependencies,
m.most_common_vals,
@ -2469,6 +2470,7 @@ pg_stats_ext_exprs| SELECT cn.nspname AS schemaname,
s.stxname AS statistics_name,
pg_get_userbyid(s.stxowner) AS statistics_owner,
stat.expr,
sd.stxdinherit AS inherited,
(stat.a).stanullfrac AS null_frac,
(stat.a).stawidth AS avg_width,
(stat.a).stadistinct AS n_distinct,

31
src/test/regress/expected/stats_ext.out
View File

@ -140,13 +140,12 @@ Statistics objects:
"public.ab1_a_b_stats" ON a, b FROM ab1; STATISTICS 0
ANALYZE ab1;
SELECT stxname, stxdndistinct, stxddependencies, stxdmcv
FROM pg_statistic_ext s, pg_statistic_ext_data d
WHERE s.stxname = 'ab1_a_b_stats'
AND d.stxoid = s.oid;
stxname | stxdndistinct | stxddependencies | stxdmcv
---------------+---------------+------------------+---------
ab1_a_b_stats | | |
SELECT stxname, stxdndistinct, stxddependencies, stxdmcv, stxdinherit
FROM pg_statistic_ext s LEFT JOIN pg_statistic_ext_data d ON (d.stxoid = s.oid)
WHERE s.stxname = 'ab1_a_b_stats';
stxname | stxdndistinct | stxddependencies | stxdmcv | stxdinherit
---------------+---------------+------------------+---------+-------------
ab1_a_b_stats | | | |
(1 row)
ALTER STATISTICS ab1_a_b_stats SET STATISTICS -1;
@ -200,12 +199,11 @@ SELECT * FROM check_estimated_rows('SELECT a, b FROM stxdinh* WHERE a = 0 AND b
CREATE STATISTICS stxdinh ON a, b FROM stxdinh;
VACUUM ANALYZE stxdinh, stxdinh1, stxdinh2;
-- Since the stats object does not include inherited stats, it should not
-- affect the estimates
-- See if the extended stats affect the estimates
SELECT * FROM check_estimated_rows('SELECT a, b FROM stxdinh* GROUP BY 1, 2');
estimated | actual
-----------+--------
400 | 150
150 | 150
(1 row)
-- Dependencies are applied at individual relations (within append), so
@ -216,6 +214,19 @@ SELECT * FROM check_estimated_rows('SELECT a, b FROM stxdinh* WHERE a = 0 AND b
22 | 40
(1 row)
-- Ensure correct (non-inherited) stats are applied to inherited query
SELECT * FROM check_estimated_rows('SELECT a, b FROM ONLY stxdinh GROUP BY 1, 2');
estimated | actual
-----------+--------
100 | 100
(1 row)
SELECT * FROM check_estimated_rows('SELECT a, b FROM ONLY stxdinh WHERE a = 0 AND b = 0');
estimated | actual
-----------+--------
20 | 20
(1 row)
DROP TABLE stxdinh, stxdinh1, stxdinh2;
-- Ensure inherited stats ARE applied to inherited query in partitioned table
CREATE TABLE stxdinp(i int, a int, b int) PARTITION BY RANGE (i);

13
src/test/regress/sql/stats_ext.sql
View File

@ -91,10 +91,9 @@ ALTER TABLE ab1 ALTER a SET STATISTICS -1;
ALTER STATISTICS ab1_a_b_stats SET STATISTICS 0;
\d ab1
ANALYZE ab1;
SELECT stxname, stxdndistinct, stxddependencies, stxdmcv
FROM pg_statistic_ext s, pg_statistic_ext_data d
WHERE s.stxname = 'ab1_a_b_stats'
AND d.stxoid = s.oid;
SELECT stxname, stxdndistinct, stxddependencies, stxdmcv, stxdinherit
FROM pg_statistic_ext s LEFT JOIN pg_statistic_ext_data d ON (d.stxoid = s.oid)
WHERE s.stxname = 'ab1_a_b_stats';
ALTER STATISTICS ab1_a_b_stats SET STATISTICS -1;
\d+ ab1
-- partial analyze doesn't build stats either
@ -126,12 +125,14 @@ SELECT * FROM check_estimated_rows('SELECT a, b FROM stxdinh* GROUP BY 1, 2');
SELECT * FROM check_estimated_rows('SELECT a, b FROM stxdinh* WHERE a = 0 AND b = 0');
CREATE STATISTICS stxdinh ON a, b FROM stxdinh;
VACUUM ANALYZE stxdinh, stxdinh1, stxdinh2;
-- Since the stats object does not include inherited stats, it should not
-- affect the estimates
-- See if the extended stats affect the estimates
SELECT * FROM check_estimated_rows('SELECT a, b FROM stxdinh* GROUP BY 1, 2');
-- Dependencies are applied at individual relations (within append), so
-- this estimate changes a bit because we improve estimates for the parent
SELECT * FROM check_estimated_rows('SELECT a, b FROM stxdinh* WHERE a = 0 AND b = 0');
-- Ensure correct (non-inherited) stats are applied to inherited query
SELECT * FROM check_estimated_rows('SELECT a, b FROM ONLY stxdinh GROUP BY 1, 2');
SELECT * FROM check_estimated_rows('SELECT a, b FROM ONLY stxdinh WHERE a = 0 AND b = 0');
DROP TABLE stxdinh, stxdinh1, stxdinh2;
-- Ensure inherited stats ARE applied to inherited query in partitioned table