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Preserve index data in pg_statistic across REINDEX CONCURRENTLY

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Statistics associated to an index got lost after running REINDEX
CONCURRENTLY, while the non-concurrent case preserves these correctly.
The concurrent and non-concurrent operations need to be consistent for
the end-user, and missing statistics would force to wait for a new
analyze to happen, which could take some time depending on the activity
of the existing autovacuum workers.  This issue is fixed by copying any
existing entries in pg_statistic associated to the old index to the new
one.  Note that this copy is already done with the data of the index in
the stats collector.

Reported-by: Fabrízio de Royes Mello
Author: Michael Paquier, Fabrízio de Royes Mello
Reviewed-by: Justin Pryzby
Discussion: https://postgr.es/m/CAFcNs+qpFPmiHd1oTXvcPdvAHicJDA9qBUSujgAhUMJyUMb+SA@mail.gmail.com
Backpatch-through: 12
This commit is contained in:
Michael Paquier 2020-11-01 21:22:07 +09:00
parent aecaa04418
commit b17ff07aa3
5 changed files with 79 additions and 0 deletions
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41
src/backend/catalog/heap.c
View File

@ -3142,6 +3142,47 @@ cookConstraint(ParseState *pstate,
return expr;
}
/*
* CopyStatistics --- copy entries in pg_statistic from one rel to another
*/
void
CopyStatistics(Oid fromrelid, Oid torelid)
{
HeapTuple tup;
SysScanDesc scan;
ScanKeyData key[1];
Relation statrel;
statrel = table_open(StatisticRelationId, RowExclusiveLock);
/* Now search for stat records */
ScanKeyInit(&key[0],
Anum_pg_statistic_starelid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(fromrelid));
scan = systable_beginscan(statrel, StatisticRelidAttnumInhIndexId,
true, NULL, 1, key);
while (HeapTupleIsValid((tup = systable_getnext(scan))))
{
Form_pg_statistic statform;
/* make a modifiable copy */
tup = heap_copytuple(tup);
statform = (Form_pg_statistic) GETSTRUCT(tup);
/* update the copy of the tuple and insert it */
statform->starelid = torelid;
CatalogTupleInsert(statrel, tup);
heap_freetuple(tup);
}
systable_endscan(scan);
table_close(statrel, RowExclusiveLock);
}
/*
* RemoveStatistics --- remove entries in pg_statistic for a rel or column

3
src/backend/catalog/index.c
View File

@ -1711,6 +1711,9 @@ index_concurrently_swap(Oid newIndexId, Oid oldIndexId, const char *oldName)
}
}
/* Copy data of pg_statistic from the old index to the new one */
CopyStatistics(oldIndexId, newIndexId);
/* Close relations */
table_close(pg_class, RowExclusiveLock);
table_close(pg_index, RowExclusiveLock);

1
src/include/catalog/heap.h
View File

@ -134,6 +134,7 @@ extern void RemoveAttributeById(Oid relid, AttrNumber attnum);
extern void RemoveAttrDefault(Oid relid, AttrNumber attnum,
DropBehavior behavior, bool complain, bool internal);
extern void RemoveAttrDefaultById(Oid attrdefId);
extern void CopyStatistics(Oid fromrelid, Oid torelid);
extern void RemoveStatistics(Oid relid, AttrNumber attnum);
extern const FormData_pg_attribute *SystemAttributeDefinition(AttrNumber attno);

22
src/test/regress/expected/create_index.out
View File

@ -2551,6 +2551,17 @@ CREATE UNIQUE INDEX concur_exprs_index_pred ON concur_exprs_tab (c1)
CREATE UNIQUE INDEX concur_exprs_index_pred_2
ON concur_exprs_tab ((1 / c1))
WHERE ('-H') >= (c2::TEXT) COLLATE "C";
ANALYZE concur_exprs_tab;
SELECT starelid::regclass, count(*) FROM pg_statistic WHERE starelid IN (
'concur_exprs_index_expr'::regclass,
'concur_exprs_index_pred'::regclass,
'concur_exprs_index_pred_2'::regclass)
GROUP BY starelid ORDER BY starelid::regclass::text;
starelid | count
-------------------------+-------
concur_exprs_index_expr | 1
(1 row)
SELECT pg_get_indexdef('concur_exprs_index_expr'::regclass);
pg_get_indexdef
---------------------------------------------------------------------------------------------------------------
@ -2608,6 +2619,17 @@ SELECT pg_get_indexdef('concur_exprs_index_pred_2'::regclass);
CREATE UNIQUE INDEX concur_exprs_index_pred_2 ON public.concur_exprs_tab USING btree (((1 / c1))) WHERE ('-H'::text >= (c2 COLLATE "C"))
(1 row)
-- Statistics should remain intact.
SELECT starelid::regclass, count(*) FROM pg_statistic WHERE starelid IN (
'concur_exprs_index_expr'::regclass,
'concur_exprs_index_pred'::regclass,
'concur_exprs_index_pred_2'::regclass)
GROUP BY starelid ORDER BY starelid::regclass::text;
starelid | count
-------------------------+-------
concur_exprs_index_expr | 1
(1 row)
DROP TABLE concur_exprs_tab;
-- Temporary tables and on-commit actions, where CONCURRENTLY is ignored.
-- ON COMMIT PRESERVE ROWS, the default.

12
src/test/regress/sql/create_index.sql
View File

@ -1079,6 +1079,12 @@ CREATE UNIQUE INDEX concur_exprs_index_pred ON concur_exprs_tab (c1)
CREATE UNIQUE INDEX concur_exprs_index_pred_2
ON concur_exprs_tab ((1 / c1))
WHERE ('-H') >= (c2::TEXT) COLLATE "C";
ANALYZE concur_exprs_tab;
SELECT starelid::regclass, count(*) FROM pg_statistic WHERE starelid IN (
'concur_exprs_index_expr'::regclass,
'concur_exprs_index_pred'::regclass,
'concur_exprs_index_pred_2'::regclass)
GROUP BY starelid ORDER BY starelid::regclass::text;
SELECT pg_get_indexdef('concur_exprs_index_expr'::regclass);
SELECT pg_get_indexdef('concur_exprs_index_pred'::regclass);
SELECT pg_get_indexdef('concur_exprs_index_pred_2'::regclass);
@ -1091,6 +1097,12 @@ ALTER TABLE concur_exprs_tab ALTER c2 TYPE TEXT;
SELECT pg_get_indexdef('concur_exprs_index_expr'::regclass);
SELECT pg_get_indexdef('concur_exprs_index_pred'::regclass);
SELECT pg_get_indexdef('concur_exprs_index_pred_2'::regclass);
-- Statistics should remain intact.
SELECT starelid::regclass, count(*) FROM pg_statistic WHERE starelid IN (
'concur_exprs_index_expr'::regclass,
'concur_exprs_index_pred'::regclass,
'concur_exprs_index_pred_2'::regclass)
GROUP BY starelid ORDER BY starelid::regclass::text;
DROP TABLE concur_exprs_tab;
-- Temporary tables and on-commit actions, where CONCURRENTLY is ignored.