Hi,
I took a look at this patch again to see if I can get it polished and
fixed. Per the discussion, I've removed the rd_indexattr list and
replaced it with a simple flag. While doing so, I noticed a couple of
places that should have consider (init or free) rd_hotblockingattr.
Patch 0001 is the v2, 0002 removes the rd_indexattr etc.
regards
--
Tomas Vondra
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company
>From 9728491208b9b2a9f430483b6132930d5766255f Mon Sep 17 00:00:00 2001
From: Tomas Vondra <tomas.von...@postgresql.org>
Date: Mon, 4 Oct 2021 16:10:38 +0200
Subject: [PATCH 2/2] fixes and remove rd_indexattr
---
src/backend/utils/cache/relcache.c | 28 +++++++---------------------
src/include/utils/rel.h | 2 +-
src/include/utils/relcache.h | 1 -
3 files changed, 8 insertions(+), 23 deletions(-)
diff --git a/src/backend/utils/cache/relcache.c b/src/backend/utils/cache/relcache.c
index 946e8d95f3..503c9f5bcb 100644
--- a/src/backend/utils/cache/relcache.c
+++ b/src/backend/utils/cache/relcache.c
@@ -2377,10 +2377,10 @@ RelationDestroyRelation(Relation relation, bool remember_tupdesc)
list_free_deep(relation->rd_fkeylist);
list_free(relation->rd_indexlist);
list_free(relation->rd_statlist);
- bms_free(relation->rd_indexattr);
bms_free(relation->rd_keyattr);
bms_free(relation->rd_pkattr);
bms_free(relation->rd_idattr);
+ bms_free(relation->rd_hotblockingattr);
if (relation->rd_pubactions)
pfree(relation->rd_pubactions);
if (relation->rd_options)
@@ -5002,7 +5002,6 @@ RelationGetIndexPredicate(Relation relation)
Bitmapset *
RelationGetIndexAttrBitmap(Relation relation, IndexAttrBitmapKind attrKind)
{
- Bitmapset *indexattrs; /* indexed columns */
Bitmapset *uindexattrs; /* columns in unique indexes */
Bitmapset *pkindexattrs; /* columns in the primary index */
Bitmapset *idindexattrs; /* columns in the replica identity */
@@ -5015,12 +5014,10 @@ RelationGetIndexAttrBitmap(Relation relation, IndexAttrBitmapKind attrKind)
MemoryContext oldcxt;
/* Quick exit if we already computed the result. */
- if (relation->rd_indexattr != NULL)
+ if (relation->rd_attrsvalid)
{
switch (attrKind)
{
- case INDEX_ATTR_BITMAP_ALL:
- return bms_copy(relation->rd_indexattr);
case INDEX_ATTR_BITMAP_KEY:
return bms_copy(relation->rd_keyattr);
case INDEX_ATTR_BITMAP_PRIMARY_KEY:
@@ -5059,7 +5056,7 @@ restart:
relreplindex = relation->rd_replidindex;
/*
- * For each index, add referenced attributes to indexattrs.
+ * For each index, add referenced attributes to appropriate bitmaps.
*
* Note: we consider all indexes returned by RelationGetIndexList, even if
* they are not indisready or indisvalid. This is important because an
@@ -5068,7 +5065,6 @@ restart:
* CONCURRENTLY is far enough along that we should ignore the index, it
* won't be returned at all by RelationGetIndexList.
*/
- indexattrs = NULL;
uindexattrs = NULL;
pkindexattrs = NULL;
idindexattrs = NULL;
@@ -5137,9 +5133,6 @@ restart:
*/
if (attrnum != 0)
{
- indexattrs = bms_add_member(indexattrs,
- attrnum - FirstLowInvalidHeapAttributeNumber);
-
if (indexDesc->rd_indam->amhotblocking)
hotblockingattrs = bms_add_member(hotblockingattrs,
attrnum - FirstLowInvalidHeapAttributeNumber);
@@ -5159,12 +5152,10 @@ restart:
}
/* Collect all attributes used in expressions, too */
- pull_varattnos(indexExpressions, 1, &indexattrs);
if (indexDesc->rd_indam->amhotblocking)
pull_varattnos(indexExpressions, 1, &hotblockingattrs);
/* Collect all attributes in the index predicate, too */
- pull_varattnos(indexPredicate, 1, &indexattrs);
if (indexDesc->rd_indam->amhotblocking)
pull_varattnos(indexPredicate, 1, &hotblockingattrs);
@@ -5196,14 +5187,11 @@ restart:
bms_free(pkindexattrs);
bms_free(idindexattrs);
bms_free(hotblockingattrs);
- bms_free(indexattrs);
goto restart;
}
/* Don't leak the old values of these bitmaps, if any */
- bms_free(relation->rd_indexattr);
- relation->rd_indexattr = NULL;
bms_free(relation->rd_keyattr);
relation->rd_keyattr = NULL;
bms_free(relation->rd_pkattr);
@@ -5215,8 +5203,8 @@ restart:
/*
* Now save copies of the bitmaps in the relcache entry. We intentionally
- * set rd_indexattr last, because that's the one that signals validity of
- * the values; if we run out of memory before making that copy, we won't
+ * set rd_attrsvalid last, because that's what signals validity of the
+ * values; if we run out of memory before making that copy, we won't
* leave the relcache entry looking like the other ones are valid but
* empty.
*/
@@ -5225,14 +5213,12 @@ restart:
relation->rd_pkattr = bms_copy(pkindexattrs);
relation->rd_idattr = bms_copy(idindexattrs);
relation->rd_hotblockingattr = bms_copy(hotblockingattrs);
- relation->rd_indexattr = bms_copy(indexattrs);
+ relation->rd_attrsvalid = true;
MemoryContextSwitchTo(oldcxt);
/* We return our original working copy for caller to play with */
switch (attrKind)
{
- case INDEX_ATTR_BITMAP_ALL:
- return indexattrs;
case INDEX_ATTR_BITMAP_KEY:
return uindexattrs;
case INDEX_ATTR_BITMAP_PRIMARY_KEY:
@@ -6089,10 +6075,10 @@ load_relcache_init_file(bool shared)
rel->rd_indexlist = NIL;
rel->rd_pkindex = InvalidOid;
rel->rd_replidindex = InvalidOid;
- rel->rd_indexattr = NULL;
rel->rd_keyattr = NULL;
rel->rd_pkattr = NULL;
rel->rd_idattr = NULL;
+ rel->rd_hotblockingattr = NULL;
rel->rd_pubactions = NULL;
rel->rd_statvalid = false;
rel->rd_statlist = NIL;
diff --git a/src/include/utils/rel.h b/src/include/utils/rel.h
index 1bde51ab25..31281279cf 100644
--- a/src/include/utils/rel.h
+++ b/src/include/utils/rel.h
@@ -155,7 +155,7 @@ typedef struct RelationData
List *rd_statlist; /* list of OIDs of extended stats */
/* data managed by RelationGetIndexAttrBitmap: */
- Bitmapset *rd_indexattr; /* identifies columns used in indexes */
+ bool rd_attrsvalid; /* are bitmaps of attrs valid? */
Bitmapset *rd_keyattr; /* cols that can be ref'd by foreign keys */
Bitmapset *rd_pkattr; /* cols included in primary key */
Bitmapset *rd_idattr; /* included in replica identity index */
diff --git a/src/include/utils/relcache.h b/src/include/utils/relcache.h
index bf575bedf8..e9f72535cd 100644
--- a/src/include/utils/relcache.h
+++ b/src/include/utils/relcache.h
@@ -55,7 +55,6 @@ extern bytea **RelationGetIndexAttOptions(Relation relation, bool copy);
typedef enum IndexAttrBitmapKind
{
- INDEX_ATTR_BITMAP_ALL,
INDEX_ATTR_BITMAP_KEY,
INDEX_ATTR_BITMAP_PRIMARY_KEY,
INDEX_ATTR_BITMAP_IDENTITY_KEY,
--
2.31.1
>From 29bf6acba8c8ad41dad7406862437ef4fc84cede Mon Sep 17 00:00:00 2001
From: Tomas Vondra <tomas.von...@postgresql.org>
Date: Mon, 4 Oct 2021 15:10:45 +0200
Subject: [PATCH 1/2] v2
---
src/backend/access/brin/brin.c | 1 +
src/backend/access/gin/ginutil.c | 1 +
src/backend/access/gist/gist.c | 1 +
src/backend/access/hash/hash.c | 1 +
src/backend/access/heap/heapam.c | 2 +-
src/backend/access/nbtree/nbtree.c | 1 +
src/backend/access/spgist/spgutils.c | 1 +
src/backend/utils/cache/relcache.c | 19 +++++++
src/include/access/amapi.h | 2 +
src/include/utils/rel.h | 1 +
src/include/utils/relcache.h | 3 +-
.../modules/dummy_index_am/dummy_index_am.c | 1 +
src/test/regress/expected/brin.out | 49 +++++++++++++++++++
src/test/regress/sql/brin.sql | 46 +++++++++++++++++
14 files changed, 127 insertions(+), 2 deletions(-)
diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index ccc9fa0959..f521bb9635 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -108,6 +108,7 @@ brinhandler(PG_FUNCTION_ARGS)
amroutine->amcanparallel = false;
amroutine->amcaninclude = false;
amroutine->amusemaintenanceworkmem = false;
+ amroutine->amhotblocking = false;
amroutine->amparallelvacuumoptions =
VACUUM_OPTION_PARALLEL_CLEANUP;
amroutine->amkeytype = InvalidOid;
diff --git a/src/backend/access/gin/ginutil.c b/src/backend/access/gin/ginutil.c
index 6d2d71be32..066cf3e11a 100644
--- a/src/backend/access/gin/ginutil.c
+++ b/src/backend/access/gin/ginutil.c
@@ -56,6 +56,7 @@ ginhandler(PG_FUNCTION_ARGS)
amroutine->amcanparallel = false;
amroutine->amcaninclude = false;
amroutine->amusemaintenanceworkmem = true;
+ amroutine->amhotblocking = true;
amroutine->amparallelvacuumoptions =
VACUUM_OPTION_PARALLEL_BULKDEL | VACUUM_OPTION_PARALLEL_CLEANUP;
amroutine->amkeytype = InvalidOid;
diff --git a/src/backend/access/gist/gist.c b/src/backend/access/gist/gist.c
index 0683f42c25..d96ce1c0a9 100644
--- a/src/backend/access/gist/gist.c
+++ b/src/backend/access/gist/gist.c
@@ -77,6 +77,7 @@ gisthandler(PG_FUNCTION_ARGS)
amroutine->amcanparallel = false;
amroutine->amcaninclude = true;
amroutine->amusemaintenanceworkmem = false;
+ amroutine->amhotblocking = true;
amroutine->amparallelvacuumoptions =
VACUUM_OPTION_PARALLEL_BULKDEL | VACUUM_OPTION_PARALLEL_COND_CLEANUP;
amroutine->amkeytype = InvalidOid;
diff --git a/src/backend/access/hash/hash.c b/src/backend/access/hash/hash.c
index eb3810494f..81c7da7ec6 100644
--- a/src/backend/access/hash/hash.c
+++ b/src/backend/access/hash/hash.c
@@ -74,6 +74,7 @@ hashhandler(PG_FUNCTION_ARGS)
amroutine->amcanparallel = false;
amroutine->amcaninclude = false;
amroutine->amusemaintenanceworkmem = false;
+ amroutine->amhotblocking = true;
amroutine->amparallelvacuumoptions =
VACUUM_OPTION_PARALLEL_BULKDEL;
amroutine->amkeytype = INT4OID;
diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c
index 2da2be1696..c7f332d673 100644
--- a/src/backend/access/heap/heapam.c
+++ b/src/backend/access/heap/heapam.c
@@ -3224,7 +3224,7 @@ heap_update(Relation relation, ItemPointer otid, HeapTuple newtup,
* Note that we get copies of each bitmap, so we need not worry about
* relcache flush happening midway through.
*/
- hot_attrs = RelationGetIndexAttrBitmap(relation, INDEX_ATTR_BITMAP_ALL);
+ hot_attrs = RelationGetIndexAttrBitmap(relation, INDEX_ATTR_BITMAP_HOT_BLOCKING);
key_attrs = RelationGetIndexAttrBitmap(relation, INDEX_ATTR_BITMAP_KEY);
id_attrs = RelationGetIndexAttrBitmap(relation,
INDEX_ATTR_BITMAP_IDENTITY_KEY);
diff --git a/src/backend/access/nbtree/nbtree.c b/src/backend/access/nbtree/nbtree.c
index 40ad0956e0..bd6d6b1cc9 100644
--- a/src/backend/access/nbtree/nbtree.c
+++ b/src/backend/access/nbtree/nbtree.c
@@ -113,6 +113,7 @@ bthandler(PG_FUNCTION_ARGS)
amroutine->amcanparallel = true;
amroutine->amcaninclude = true;
amroutine->amusemaintenanceworkmem = false;
+ amroutine->amhotblocking = true;
amroutine->amparallelvacuumoptions =
VACUUM_OPTION_PARALLEL_BULKDEL | VACUUM_OPTION_PARALLEL_COND_CLEANUP;
amroutine->amkeytype = InvalidOid;
diff --git a/src/backend/access/spgist/spgutils.c b/src/backend/access/spgist/spgutils.c
index 03a9cd36e6..a2cabb9d81 100644
--- a/src/backend/access/spgist/spgutils.c
+++ b/src/backend/access/spgist/spgutils.c
@@ -61,6 +61,7 @@ spghandler(PG_FUNCTION_ARGS)
amroutine->amcanparallel = false;
amroutine->amcaninclude = true;
amroutine->amusemaintenanceworkmem = false;
+ amroutine->amhotblocking = true;
amroutine->amparallelvacuumoptions =
VACUUM_OPTION_PARALLEL_BULKDEL | VACUUM_OPTION_PARALLEL_COND_CLEANUP;
amroutine->amkeytype = InvalidOid;
diff --git a/src/backend/utils/cache/relcache.c b/src/backend/utils/cache/relcache.c
index 13d9994af3..946e8d95f3 100644
--- a/src/backend/utils/cache/relcache.c
+++ b/src/backend/utils/cache/relcache.c
@@ -5006,6 +5006,7 @@ RelationGetIndexAttrBitmap(Relation relation, IndexAttrBitmapKind attrKind)
Bitmapset *uindexattrs; /* columns in unique indexes */
Bitmapset *pkindexattrs; /* columns in the primary index */
Bitmapset *idindexattrs; /* columns in the replica identity */
+ Bitmapset *hotblockingattrs; /* columns with HOT blocking indexes */
List *indexoidlist;
List *newindexoidlist;
Oid relpkindex;
@@ -5026,6 +5027,8 @@ RelationGetIndexAttrBitmap(Relation relation, IndexAttrBitmapKind attrKind)
return bms_copy(relation->rd_pkattr);
case INDEX_ATTR_BITMAP_IDENTITY_KEY:
return bms_copy(relation->rd_idattr);
+ case INDEX_ATTR_BITMAP_HOT_BLOCKING:
+ return bms_copy(relation->rd_hotblockingattr);
default:
elog(ERROR, "unknown attrKind %u", attrKind);
}
@@ -5069,6 +5072,7 @@ restart:
uindexattrs = NULL;
pkindexattrs = NULL;
idindexattrs = NULL;
+ hotblockingattrs = NULL;
foreach(l, indexoidlist)
{
Oid indexOid = lfirst_oid(l);
@@ -5136,6 +5140,10 @@ restart:
indexattrs = bms_add_member(indexattrs,
attrnum - FirstLowInvalidHeapAttributeNumber);
+ if (indexDesc->rd_indam->amhotblocking)
+ hotblockingattrs = bms_add_member(hotblockingattrs,
+ attrnum - FirstLowInvalidHeapAttributeNumber);
+
if (isKey && i < indexDesc->rd_index->indnkeyatts)
uindexattrs = bms_add_member(uindexattrs,
attrnum - FirstLowInvalidHeapAttributeNumber);
@@ -5152,9 +5160,14 @@ restart:
/* Collect all attributes used in expressions, too */
pull_varattnos(indexExpressions, 1, &indexattrs);
+ if (indexDesc->rd_indam->amhotblocking)
+ pull_varattnos(indexExpressions, 1, &hotblockingattrs);
/* Collect all attributes in the index predicate, too */
pull_varattnos(indexPredicate, 1, &indexattrs);
+ if (indexDesc->rd_indam->amhotblocking)
+ pull_varattnos(indexPredicate, 1, &hotblockingattrs);
+
index_close(indexDesc, AccessShareLock);
}
@@ -5182,6 +5195,7 @@ restart:
bms_free(uindexattrs);
bms_free(pkindexattrs);
bms_free(idindexattrs);
+ bms_free(hotblockingattrs);
bms_free(indexattrs);
goto restart;
@@ -5196,6 +5210,8 @@ restart:
relation->rd_pkattr = NULL;
bms_free(relation->rd_idattr);
relation->rd_idattr = NULL;
+ bms_free(relation->rd_hotblockingattr);
+ relation->rd_hotblockingattr = NULL;
/*
* Now save copies of the bitmaps in the relcache entry. We intentionally
@@ -5208,6 +5224,7 @@ restart:
relation->rd_keyattr = bms_copy(uindexattrs);
relation->rd_pkattr = bms_copy(pkindexattrs);
relation->rd_idattr = bms_copy(idindexattrs);
+ relation->rd_hotblockingattr = bms_copy(hotblockingattrs);
relation->rd_indexattr = bms_copy(indexattrs);
MemoryContextSwitchTo(oldcxt);
@@ -5222,6 +5239,8 @@ restart:
return pkindexattrs;
case INDEX_ATTR_BITMAP_IDENTITY_KEY:
return idindexattrs;
+ case INDEX_ATTR_BITMAP_HOT_BLOCKING:
+ return hotblockingattrs;
default:
elog(ERROR, "unknown attrKind %u", attrKind);
return NULL;
diff --git a/src/include/access/amapi.h b/src/include/access/amapi.h
index d357ebb559..a0ab70df89 100644
--- a/src/include/access/amapi.h
+++ b/src/include/access/amapi.h
@@ -244,6 +244,8 @@ typedef struct IndexAmRoutine
bool amcaninclude;
/* does AM use maintenance_work_mem? */
bool amusemaintenanceworkmem;
+ /* does AM block HOT update? */
+ bool amhotblocking;
/* OR of parallel vacuum flags. See vacuum.h for flags. */
uint8 amparallelvacuumoptions;
/* type of data stored in index, or InvalidOid if variable */
diff --git a/src/include/utils/rel.h b/src/include/utils/rel.h
index b4faa1c123..1bde51ab25 100644
--- a/src/include/utils/rel.h
+++ b/src/include/utils/rel.h
@@ -159,6 +159,7 @@ typedef struct RelationData
Bitmapset *rd_keyattr; /* cols that can be ref'd by foreign keys */
Bitmapset *rd_pkattr; /* cols included in primary key */
Bitmapset *rd_idattr; /* included in replica identity index */
+ Bitmapset *rd_hotblockingattr; /* cols blocking HOT update */
PublicationActions *rd_pubactions; /* publication actions */
diff --git a/src/include/utils/relcache.h b/src/include/utils/relcache.h
index d2c17575f6..bf575bedf8 100644
--- a/src/include/utils/relcache.h
+++ b/src/include/utils/relcache.h
@@ -58,7 +58,8 @@ typedef enum IndexAttrBitmapKind
INDEX_ATTR_BITMAP_ALL,
INDEX_ATTR_BITMAP_KEY,
INDEX_ATTR_BITMAP_PRIMARY_KEY,
- INDEX_ATTR_BITMAP_IDENTITY_KEY
+ INDEX_ATTR_BITMAP_IDENTITY_KEY,
+ INDEX_ATTR_BITMAP_HOT_BLOCKING
} IndexAttrBitmapKind;
extern Bitmapset *RelationGetIndexAttrBitmap(Relation relation,
diff --git a/src/test/modules/dummy_index_am/dummy_index_am.c b/src/test/modules/dummy_index_am/dummy_index_am.c
index 5365b0639e..9d409faff5 100644
--- a/src/test/modules/dummy_index_am/dummy_index_am.c
+++ b/src/test/modules/dummy_index_am/dummy_index_am.c
@@ -298,6 +298,7 @@ dihandler(PG_FUNCTION_ARGS)
amroutine->amcanparallel = false;
amroutine->amcaninclude = false;
amroutine->amusemaintenanceworkmem = false;
+ amroutine->amhotblocking = true;
amroutine->amparallelvacuumoptions = VACUUM_OPTION_NO_PARALLEL;
amroutine->amkeytype = InvalidOid;
diff --git a/src/test/regress/expected/brin.out b/src/test/regress/expected/brin.out
index e53d6e4885..08dab22b1c 100644
--- a/src/test/regress/expected/brin.out
+++ b/src/test/regress/expected/brin.out
@@ -567,3 +567,52 @@ SELECT * FROM brintest_3 WHERE b < '0';
DROP TABLE brintest_3;
RESET enable_seqscan;
+-- test BRIN index doesn't block HOT update
+CREATE TABLE brin_hot (
+ id integer PRIMARY KEY,
+ val integer NOT NULL
+) WITH (autovacuum_enabled = off, fillfactor = 70);
+INSERT INTO brin_hot SELECT *, 0 FROM generate_series(1, 235);
+CREATE INDEX val_brin ON brin_hot using brin(val);
+CREATE FUNCTION wait_for_hot_stats() RETURNS void AS $$
+DECLARE
+ start_time timestamptz := clock_timestamp();
+ updated bool;
+BEGIN
+ -- we don't want to wait forever; loop will exit after 30 seconds
+ FOR i IN 1 .. 300 LOOP
+ SELECT (pg_stat_get_tuples_hot_updated('brin_hot'::regclass::oid) > 0) INTO updated;
+ EXIT WHEN updated;
+
+ -- wait a little
+ PERFORM pg_sleep_for('100 milliseconds');
+ -- reset stats snapshot so we can test again
+ PERFORM pg_stat_clear_snapshot();
+ END LOOP;
+ -- report time waited in postmaster log (where it won't change test output)
+ RAISE log 'wait_for_hot_stats delayed % seconds',
+ EXTRACT(epoch FROM clock_timestamp() - start_time);
+END
+$$ LANGUAGE plpgsql;
+UPDATE brin_hot SET val = -3 WHERE id = 42;
+-- We can't just call wait_for_hot_stats() at this point, because we only
+-- transmit stats when the session goes idle, and we probably didn't
+-- transmit the last couple of counts yet thanks to the rate-limiting logic
+-- in pgstat_report_stat(). But instead of waiting for the rate limiter's
+-- timeout to elapse, let's just start a new session. The old one will
+-- then send its stats before dying.
+\c -
+SELECT wait_for_hot_stats();
+ wait_for_hot_stats
+--------------------
+
+(1 row)
+
+SELECT pg_stat_get_tuples_hot_updated('brin_hot'::regclass::oid);
+ pg_stat_get_tuples_hot_updated
+--------------------------------
+ 1
+(1 row)
+
+DROP TABLE brin_hot;
+DROP FUNCTION wait_for_hot_stats();
diff --git a/src/test/regress/sql/brin.sql b/src/test/regress/sql/brin.sql
index 3bd866d947..740e0b77a5 100644
--- a/src/test/regress/sql/brin.sql
+++ b/src/test/regress/sql/brin.sql
@@ -509,3 +509,49 @@ SELECT * FROM brintest_3 WHERE b < '0';
DROP TABLE brintest_3;
RESET enable_seqscan;
+
+-- test BRIN index doesn't block HOT update
+CREATE TABLE brin_hot (
+ id integer PRIMARY KEY,
+ val integer NOT NULL
+) WITH (autovacuum_enabled = off, fillfactor = 70);
+
+INSERT INTO brin_hot SELECT *, 0 FROM generate_series(1, 235);
+CREATE INDEX val_brin ON brin_hot using brin(val);
+
+CREATE FUNCTION wait_for_hot_stats() RETURNS void AS $$
+DECLARE
+ start_time timestamptz := clock_timestamp();
+ updated bool;
+BEGIN
+ -- we don't want to wait forever; loop will exit after 30 seconds
+ FOR i IN 1 .. 300 LOOP
+ SELECT (pg_stat_get_tuples_hot_updated('brin_hot'::regclass::oid) > 0) INTO updated;
+ EXIT WHEN updated;
+
+ -- wait a little
+ PERFORM pg_sleep_for('100 milliseconds');
+ -- reset stats snapshot so we can test again
+ PERFORM pg_stat_clear_snapshot();
+ END LOOP;
+ -- report time waited in postmaster log (where it won't change test output)
+ RAISE log 'wait_for_hot_stats delayed % seconds',
+ EXTRACT(epoch FROM clock_timestamp() - start_time);
+END
+$$ LANGUAGE plpgsql;
+
+UPDATE brin_hot SET val = -3 WHERE id = 42;
+
+-- We can't just call wait_for_hot_stats() at this point, because we only
+-- transmit stats when the session goes idle, and we probably didn't
+-- transmit the last couple of counts yet thanks to the rate-limiting logic
+-- in pgstat_report_stat(). But instead of waiting for the rate limiter's
+-- timeout to elapse, let's just start a new session. The old one will
+-- then send its stats before dying.
+\c -
+
+SELECT wait_for_hot_stats();
+SELECT pg_stat_get_tuples_hot_updated('brin_hot'::regclass::oid);
+
+DROP TABLE brin_hot;
+DROP FUNCTION wait_for_hot_stats();
--
2.31.1
