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Create functions pg_set_relation_stats, pg_clear_relation_stats.

Browse Source 
These functions are used to tweak statistics on any relation, provided
that the user has MAINTAIN privilege on the relation, or is the database
owner.

Bump catalog version.

Author: Corey Huinker
Discussion: https://postgr.es/m/CADkLM=eErgzn7ECDpwFcptJKOk9SxZEk5Pot4d94eVTZsvj3gw@mail.gmail.com
This commit is contained in:
Jeff Davis
2024-10-11 16:55:11 -07:00
parent 6f782a2a17
commit e839c8ecc9
12 changed files with 700 additions and 3 deletions
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94
doc/src/sgml/func.sgml
View File

@ -30135,6 +30135,100 @@ DETAIL: Make sure pg_wal_replay_wait() isn't called within a transaction with a
</tgroup>
</table>
<para>
<xref linkend="functions-admin-statsmod"/> lists functions used to
manipulate statistics.
<warning>
<para>
Changes made by these statistics manipulation functions are likely to be
overwritten by <link linkend="autovacuum">autovacuum</link> (or manual
<command>VACUUM</command> or <command>ANALYZE</command>) and should be
considered temporary.
</para>
</warning>
</para>
<table id="functions-admin-statsmod">
<title>Database Object Statistics Manipulation Functions</title>
<tgroup cols="1">
<thead>
<row>
<entry role="func_table_entry"><para role="func_signature">
Function
</para>
<para>
Description
</para></entry>
</row>
</thead>
<tbody>
<row>
<entry role="func_table_entry">
<para role="func_signature">
<indexterm>
<primary>pg_set_relation_stats</primary>
</indexterm>
<function>pg_set_relation_stats</function> (
<parameter>relation</parameter> <type>regclass</type>
<optional>, <parameter>relpages</parameter> <type>integer</type></optional>
<optional>, <parameter>reltuples</parameter> <type>real</type></optional>
<optional>, <parameter>relallvisible</parameter> <type>integer</type></optional> )
<returnvalue>boolean</returnvalue>
</para>
<para>
Updates relation-level statistics for the given relation to the
specified values. The parameters correspond to columns in <link
linkend="catalog-pg-class"><structname>pg_class</structname></link>. Unspecified
or <literal>NULL</literal> values leave the setting
unchanged. Returns <literal>true</literal> if a change was made;
<literal>false</literal> otherwise.
</para>
<para>
Ordinarily, these statistics are collected automatically or updated
as a part of <xref linkend="sql-vacuum"/> or <xref
linkend="sql-analyze"/>, so it's not necessary to call this
function. However, it may be useful when testing the effects of
statistics on the planner to understand or anticipate plan changes.
</para>
<para>
The caller must have the <literal>MAINTAIN</literal> privilege on
the table or be the owner of the database.
</para>
<para>
The value of <structfield>relpages</structfield> must be greater than
or equal to <literal>0</literal>,
<structfield>reltuples</structfield> must be greater than or equal to
<literal>-1.0</literal>, and <structfield>relallvisible</structfield>
must be greater than or equal to <literal>0</literal>.
</para>
</entry>
</row>
<row>
<entry role="func_table_entry">
<para role="func_signature">
<indexterm>
<primary>pg_clear_relation_stats</primary>
</indexterm>
<function>pg_clear_relation_stats</function> ( <parameter>relation</parameter> <type>regclass</type> )
<returnvalue>boolean</returnvalue>
</para>
<para>
Clears table-level statistics for the given relation, as though the
table was newly created. Returns <literal>true</literal> if a change
was made; <literal>false</literal> otherwise.
</para>
<para>
The caller must have the <literal>MAINTAIN</literal> privilege on
the table or be the owner of the database.
</para>
</entry>
</row>
</tbody>
</tgroup>
</table>
<para>
<xref linkend="functions-info-partition"/> lists functions that provide
information about the structure of partitioned tables.

10
src/backend/catalog/system_functions.sql
View File

@ -639,6 +639,16 @@ LANGUAGE INTERNAL
CALLED ON NULL INPUT VOLATILE PARALLEL SAFE
AS 'pg_stat_reset_slru';
CREATE OR REPLACE FUNCTION
pg_set_relation_stats(relation regclass,
relpages integer DEFAULT NULL,
reltuples real DEFAULT NULL,
relallvisible integer DEFAULT NULL)
RETURNS bool
LANGUAGE INTERNAL
CALLED ON NULL INPUT VOLATILE
AS 'pg_set_relation_stats';
--
-- The default permissions for functions mean that anyone can execute them.
-- A number of functions shouldn't be executable by just anyone, but rather

4
src/backend/statistics/Makefile
View File

@ -16,6 +16,8 @@ OBJS = \
dependencies.o \
extended_stats.o \
mcv.o \
mvdistinct.o
mvdistinct.o \
relation_stats.o \
stat_utils.o
include $(top_srcdir)/src/backend/common.mk

2
src/backend/statistics/meson.build
View File

@ -5,4 +5,6 @@ backend_sources += files(
'extended_stats.c',
'mcv.c',
'mvdistinct.c',
'relation_stats.c',
'stat_utils.c'
)

210
src/backend/statistics/relation_stats.c Normal file
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@ -0,0 +1,210 @@
/*-------------------------------------------------------------------------
* relation_stats.c
*
* PostgreSQL relation statistics manipulation
*
* Code supporting the direct import of relation statistics, similar to
* what is done by the ANALYZE command.
*
* Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* src/backend/statistics/relation_stats.c
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "access/heapam.h"
#include "catalog/indexing.h"
#include "statistics/stat_utils.h"
#include "utils/fmgrprotos.h"
#include "utils/syscache.h"
#define DEFAULT_RELPAGES Int32GetDatum(0)
#define DEFAULT_RELTUPLES Float4GetDatum(-1.0)
#define DEFAULT_RELALLVISIBLE Int32GetDatum(0)
/*
* Positional argument numbers, names, and types for
* relation_statistics_update().
*/
enum relation_stats_argnum
{
RELATION_ARG = 0,
RELPAGES_ARG,
RELTUPLES_ARG,
RELALLVISIBLE_ARG,
NUM_RELATION_STATS_ARGS
};
static struct StatsArgInfo relarginfo[] =
{
[RELATION_ARG] = {"relation", REGCLASSOID},
[RELPAGES_ARG] = {"relpages", INT4OID},
[RELTUPLES_ARG] = {"reltuples", FLOAT4OID},
[RELALLVISIBLE_ARG] = {"relallvisible", INT4OID},
[NUM_RELATION_STATS_ARGS] = {0}
};
static bool relation_statistics_update(FunctionCallInfo fcinfo, int elevel);
/*
* Internal function for modifying statistics for a relation.
*/
static bool
relation_statistics_update(FunctionCallInfo fcinfo, int elevel)
{
Oid reloid;
Relation crel;
HeapTuple ctup;
Form_pg_class pgcform;
int replaces[3] = {0};
Datum values[3] = {0};
bool nulls[3] = {0};
int ncols = 0;
TupleDesc tupdesc;
HeapTuple newtup;
stats_check_required_arg(fcinfo, relarginfo, RELATION_ARG);
reloid = PG_GETARG_OID(RELATION_ARG);
stats_lock_check_privileges(reloid);
/*
* Take RowExclusiveLock on pg_class, consistent with
* vac_update_relstats().
*/
crel = table_open(RelationRelationId, RowExclusiveLock);
tupdesc = RelationGetDescr(crel);
ctup = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(reloid));
if (!HeapTupleIsValid(ctup))
{
ereport(elevel,
(errcode(ERRCODE_OBJECT_IN_USE),
errmsg("pg_class entry for relid %u not found", reloid)));
table_close(crel, RowExclusiveLock);
return false;
}
pgcform = (Form_pg_class) GETSTRUCT(ctup);
/* relpages */
if (!PG_ARGISNULL(RELPAGES_ARG))
{
int32 relpages = PG_GETARG_INT32(RELPAGES_ARG);
if (relpages < -1)
{
ereport(elevel,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("relpages cannot be < -1")));
table_close(crel, RowExclusiveLock);
return false;
}
if (relpages != pgcform->relpages)
{
replaces[ncols] = Anum_pg_class_relpages;
values[ncols] = Int32GetDatum(relpages);
ncols++;
}
}
if (!PG_ARGISNULL(RELTUPLES_ARG))
{
float reltuples = PG_GETARG_FLOAT4(RELTUPLES_ARG);
if (reltuples < -1.0)
{
ereport(elevel,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("reltuples cannot be < -1.0")));
table_close(crel, RowExclusiveLock);
return false;
}
if (reltuples != pgcform->reltuples)
{
replaces[ncols] = Anum_pg_class_reltuples;
values[ncols] = Float4GetDatum(reltuples);
ncols++;
}
}
if (!PG_ARGISNULL(RELALLVISIBLE_ARG))
{
int32 relallvisible = PG_GETARG_INT32(RELALLVISIBLE_ARG);
if (relallvisible < 0)
{
ereport(elevel,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("relallvisible cannot be < 0")));
table_close(crel, RowExclusiveLock);
return false;
}
if (relallvisible != pgcform->relallvisible)
{
replaces[ncols] = Anum_pg_class_relallvisible;
values[ncols] = Int32GetDatum(relallvisible);
ncols++;
}
}
/* only update pg_class if there is a meaningful change */
if (ncols == 0)
{
table_close(crel, RowExclusiveLock);
return false;
}
newtup = heap_modify_tuple_by_cols(ctup, tupdesc, ncols, replaces, values,
nulls);
CatalogTupleUpdate(crel, &newtup->t_self, newtup);
heap_freetuple(newtup);
/* release the lock, consistent with vac_update_relstats() */
table_close(crel, RowExclusiveLock);
return true;
}
/*
* Set statistics for a given pg_class entry.
*/
Datum
pg_set_relation_stats(PG_FUNCTION_ARGS)
{
PG_RETURN_BOOL(relation_statistics_update(fcinfo, ERROR));
}
/*
* Clear statistics for a given pg_class entry; that is, set back to initial
* stats for a newly-created table.
*/
Datum
pg_clear_relation_stats(PG_FUNCTION_ARGS)
{
LOCAL_FCINFO(newfcinfo, 4);
InitFunctionCallInfoData(*newfcinfo, NULL, 4, InvalidOid, NULL, NULL);
newfcinfo->args[0].value = PG_GETARG_OID(0);
newfcinfo->args[0].isnull = PG_ARGISNULL(0);
newfcinfo->args[1].value = DEFAULT_RELPAGES;
newfcinfo->args[1].isnull = false;
newfcinfo->args[2].value = DEFAULT_RELTUPLES;
newfcinfo->args[2].isnull = false;
newfcinfo->args[3].value = DEFAULT_RELALLVISIBLE;
newfcinfo->args[3].isnull = false;
PG_RETURN_BOOL(relation_statistics_update(newfcinfo, ERROR));
}

94
src/backend/statistics/stat_utils.c Normal file
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@ -0,0 +1,94 @@
/*-------------------------------------------------------------------------
* stat_utils.c
*
* PostgreSQL statistics manipulation utilities.
*
* Code supporting the direct manipulation of statistics.
*
* Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* src/backend/statistics/stat_utils.c
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "access/relation.h"
#include "catalog/pg_database.h"
#include "miscadmin.h"
#include "statistics/stat_utils.h"
#include "utils/array.h"
#include "utils/builtins.h"
#include "utils/acl.h"
#include "utils/rel.h"
/*
* Ensure that a given argument is not null.
*/
void
stats_check_required_arg(FunctionCallInfo fcinfo,
struct StatsArgInfo *arginfo,
int argnum)
{
if (PG_ARGISNULL(argnum))
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("\"%s\" cannot be NULL",
arginfo[argnum].argname)));
}
/*
* Lock relation in ShareUpdateExclusive mode, check privileges, and close the
* relation (but retain the lock).
*
* A role has privileges to set statistics on the relation if any of the
* following are true:
* - the role owns the current database and the relation is not shared
* - the role has the MAINTAIN privilege on the relation
*/
void
stats_lock_check_privileges(Oid reloid)
{
Relation rel = relation_open(reloid, ShareUpdateExclusiveLock);
const char relkind = rel->rd_rel->relkind;
/* All of the types that can be used with ANALYZE, plus indexes */
switch (relkind)
{
case RELKIND_RELATION:
case RELKIND_INDEX:
case RELKIND_MATVIEW:
case RELKIND_FOREIGN_TABLE:
case RELKIND_PARTITIONED_TABLE:
case RELKIND_PARTITIONED_INDEX:
break;
default:
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("cannot modify statistics for relation \"%s\"",
RelationGetRelationName(rel)),
errdetail_relkind_not_supported(rel->rd_rel->relkind)));
}
if (rel->rd_rel->relisshared)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot modify statistics for shared relation")));
if (!object_ownercheck(DatabaseRelationId, MyDatabaseId, GetUserId()))
{
AclResult aclresult = pg_class_aclcheck(RelationGetRelid(rel),
GetUserId(),
ACL_MAINTAIN);
if (aclresult != ACLCHECK_OK)
aclcheck_error(aclresult,
get_relkind_objtype(rel->rd_rel->relkind),
NameStr(rel->rd_rel->relname));
}
relation_close(rel, NoLock);
}

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

@ -57,6 +57,6 @@
*/
/* yyyymmddN */
#define CATALOG_VERSION_NO 202410113
#define CATALOG_VERSION_NO 202410114
#endif

15
src/include/catalog/pg_proc.dat
View File

@ -12341,6 +12341,21 @@
proallargtypes => '{int8,pg_lsn,pg_lsn,int4}', proargmodes => '{o,o,o,o}',
proargnames => '{summarized_tli,summarized_lsn,pending_lsn,summarizer_pid}',
prosrc => 'pg_get_wal_summarizer_state' },
+# Statistics Import
{ oid => '9944',
descr => 'set statistics on relation',
proname => 'pg_set_relation_stats', provolatile => 'v', proisstrict => 'f',
proparallel => 'u', prorettype => 'bool',
proargtypes => 'regclass int4 float4 int4',
proargnames => '{relation,relpages,reltuples,relallvisible}',
prosrc => 'pg_set_relation_stats' },
{ oid => '9945',
descr => 'clear statistics on relation',
proname => 'pg_clear_relation_stats', provolatile => 'v', proisstrict => 'f',
proparallel => 'u', prorettype => 'bool',
proargtypes => 'regclass',
proargnames => '{relation}',
prosrc => 'pg_clear_relation_stats' },
# GiST stratnum implementations
{ oid => '8047', descr => 'GiST support',

29
src/include/statistics/stat_utils.h Normal file
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@ -0,0 +1,29 @@
/*-------------------------------------------------------------------------
*
* stat_utils.h
* Extended statistics and selectivity estimation functions.
*
* Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* src/include/statistics/stat_utils.h
*
*-------------------------------------------------------------------------
*/
#ifndef STATS_UTILS_H
#define STATS_UTILS_H
#include "fmgr.h"
struct StatsArgInfo
{
const char *argname;
Oid argtype;
};
extern void stats_check_required_arg(FunctionCallInfo fcinfo,
struct StatsArgInfo *arginfo,
int argnum);
extern void stats_lock_check_privileges(Oid reloid);
#endif /* STATS_UTILS_H */

143
src/test/regress/expected/stats_import.out Normal file
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@ -0,0 +1,143 @@
CREATE SCHEMA stats_import;
CREATE TYPE stats_import.complex_type AS (
a integer,
b real,
c text,
d date,
e jsonb);
CREATE TABLE stats_import.test(
id INTEGER PRIMARY KEY,
name text,
comp stats_import.complex_type,
arange int4range,
tags text[]
);
-- starting stats
SELECT relpages, reltuples, relallvisible
FROM pg_class
WHERE oid = 'stats_import.test'::regclass;
relpages | reltuples | relallvisible
----------+-----------+---------------
0 | -1 | 0
(1 row)
-- error: regclass not found
SELECT
pg_catalog.pg_set_relation_stats(
relation => 0::Oid,
relpages => 17::integer,
reltuples => 400.0::real,
relallvisible => 4::integer);
ERROR: could not open relation with OID 0
-- relpages default
SELECT
pg_catalog.pg_set_relation_stats(
relation => 'stats_import.test'::regclass,
relpages => NULL::integer,
reltuples => 400.0::real,
relallvisible => 4::integer);
pg_set_relation_stats
-----------------------
t
(1 row)
-- reltuples default
SELECT
pg_catalog.pg_set_relation_stats(
relation => 'stats_import.test'::regclass,
relpages => 17::integer,
reltuples => NULL::real,
relallvisible => 4::integer);
pg_set_relation_stats
-----------------------
t
(1 row)
-- relallvisible default
SELECT
pg_catalog.pg_set_relation_stats(
relation => 'stats_import.test'::regclass,
relpages => 17::integer,
reltuples => 400.0::real,
relallvisible => NULL::integer);
pg_set_relation_stats
-----------------------
f
(1 row)
-- named arguments
SELECT
pg_catalog.pg_set_relation_stats(
relation => 'stats_import.test'::regclass,
relpages => 17::integer,
reltuples => 400.0::real,
relallvisible => 4::integer);
pg_set_relation_stats
-----------------------
f
(1 row)
SELECT relpages, reltuples, relallvisible
FROM pg_class
WHERE oid = 'stats_import.test'::regclass;
relpages | reltuples | relallvisible
----------+-----------+---------------
17 | 400 | 4
(1 row)
-- positional arguments
SELECT
pg_catalog.pg_set_relation_stats(
'stats_import.test'::regclass,
18::integer,
401.0::real,
5::integer);
pg_set_relation_stats
-----------------------
t
(1 row)
SELECT relpages, reltuples, relallvisible
FROM pg_class
WHERE oid = 'stats_import.test'::regclass;
relpages | reltuples | relallvisible
----------+-----------+---------------
18 | 401 | 5
(1 row)
-- clear
SELECT
pg_catalog.pg_clear_relation_stats(
'stats_import.test'::regclass);
pg_clear_relation_stats
-------------------------
t
(1 row)
SELECT relpages, reltuples, relallvisible
FROM pg_class
WHERE oid = 'stats_import.test'::regclass;
relpages | reltuples | relallvisible
----------+-----------+---------------
0 | -1 | 0
(1 row)
-- invalid relkinds for statistics
CREATE SEQUENCE stats_import.testseq;
CREATE VIEW stats_import.testview AS SELECT * FROM stats_import.test;
SELECT
pg_catalog.pg_clear_relation_stats(
'stats_import.testseq'::regclass);
ERROR: cannot modify statistics for relation "testseq"
DETAIL: This operation is not supported for sequences.
SELECT
pg_catalog.pg_clear_relation_stats(
'stats_import.testview'::regclass);
ERROR: cannot modify statistics for relation "testview"
DETAIL: This operation is not supported for views.
DROP SCHEMA stats_import CASCADE;
NOTICE: drop cascades to 4 other objects
DETAIL: drop cascades to type stats_import.complex_type
drop cascades to table stats_import.test
drop cascades to sequence stats_import.testseq
drop cascades to view stats_import.testview

2
src/test/regress/parallel_schedule
View File

@ -28,7 +28,7 @@ test: strings md5 numerology point lseg line box path polygon circle date time t
# geometry depends on point, lseg, line, box, path, polygon, circle
# horology depends on date, time, timetz, timestamp, timestamptz, interval
# ----------
test: geometry horology tstypes regex type_sanity opr_sanity misc_sanity comments expressions unicode xid mvcc database
test: geometry horology tstypes regex type_sanity opr_sanity misc_sanity comments expressions unicode xid mvcc database stats_import
# ----------
# Load huge amounts of data

98
src/test/regress/sql/stats_import.sql Normal file
View File

@ -0,0 +1,98 @@
CREATE SCHEMA stats_import;
CREATE TYPE stats_import.complex_type AS (
a integer,
b real,
c text,
d date,
e jsonb);
CREATE TABLE stats_import.test(
id INTEGER PRIMARY KEY,
name text,
comp stats_import.complex_type,
arange int4range,
tags text[]
);
-- starting stats
SELECT relpages, reltuples, relallvisible
FROM pg_class
WHERE oid = 'stats_import.test'::regclass;
-- error: regclass not found
SELECT
pg_catalog.pg_set_relation_stats(
relation => 0::Oid,
relpages => 17::integer,
reltuples => 400.0::real,
relallvisible => 4::integer);
-- relpages default
SELECT
pg_catalog.pg_set_relation_stats(
relation => 'stats_import.test'::regclass,
relpages => NULL::integer,
reltuples => 400.0::real,
relallvisible => 4::integer);
-- reltuples default
SELECT
pg_catalog.pg_set_relation_stats(
relation => 'stats_import.test'::regclass,
relpages => 17::integer,
reltuples => NULL::real,
relallvisible => 4::integer);
-- relallvisible default
SELECT
pg_catalog.pg_set_relation_stats(
relation => 'stats_import.test'::regclass,
relpages => 17::integer,
reltuples => 400.0::real,
relallvisible => NULL::integer);
-- named arguments
SELECT
pg_catalog.pg_set_relation_stats(
relation => 'stats_import.test'::regclass,
relpages => 17::integer,
reltuples => 400.0::real,
relallvisible => 4::integer);
SELECT relpages, reltuples, relallvisible
FROM pg_class
WHERE oid = 'stats_import.test'::regclass;
-- positional arguments
SELECT
pg_catalog.pg_set_relation_stats(
'stats_import.test'::regclass,
18::integer,
401.0::real,
5::integer);
SELECT relpages, reltuples, relallvisible
FROM pg_class
WHERE oid = 'stats_import.test'::regclass;
-- clear
SELECT
pg_catalog.pg_clear_relation_stats(
'stats_import.test'::regclass);
SELECT relpages, reltuples, relallvisible
FROM pg_class
WHERE oid = 'stats_import.test'::regclass;
-- invalid relkinds for statistics
CREATE SEQUENCE stats_import.testseq;
CREATE VIEW stats_import.testview AS SELECT * FROM stats_import.test;
SELECT
pg_catalog.pg_clear_relation_stats(
'stats_import.testseq'::regclass);
SELECT
pg_catalog.pg_clear_relation_stats(
'stats_import.testview'::regclass);
DROP SCHEMA stats_import CASCADE;