Revert changes in HOT handling of BRIN indexes

This reverts commits 5753d4ee32 and fe60b67250 that modified HOT to
ignore BRIN indexes. The commit message for 5753d4ee32 claims that:

    When determining whether an index update may be skipped by using
    HOT, we can ignore attributes indexed only by BRIN indexes. There
    are no index pointers to individual tuples in BRIN, and the page
    range summary will be updated anyway as it relies on visibility
    info.

This is partially incorrect - it's true BRIN indexes don't point to
individual tuples, so HOT chains are not an issue, but the visibitlity
info is not sufficient to keep the index up to date. This can easily
result in corrupted indexes, as demonstrated in the hackers thread.

This does not mean relaxing the HOT restrictions for BRIN is a lost
cause, but it needs to handle the two aspects (allowing HOT chains and
updating the page range summaries) as separate. But that requires a
major changes, and it's too late for that in the current dev cycle.

Reported-by: Tomas Vondra
Discussion: https://postgr.es/m/05ebcb44-f383-86e3-4f31-0a97a55634cf@enterprisedb.com

7 files changed, 1 insertions, 7 deletions

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index 0de1441dc6d..e88f7efa7e4 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -108,7 +108,6 @@ 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 3d15701a01e..20f470648be 100644
--- a/src/backend/access/gin/ginutil.c
+++ b/src/backend/access/gin/ginutil.c
@@ -56,7 +56,6 @@ 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 8c6c744ab74..5866c6aaaf7 100644
--- a/src/backend/access/gist/gist.c
+++ b/src/backend/access/gist/gist.c
@@ -78,7 +78,6 @@ 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 fd1a7119b6c..c361509d68d 100644
--- a/src/backend/access/hash/hash.c
+++ b/src/backend/access/hash/hash.c
@@ -75,7 +75,6 @@ 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 74218510276..637de1116c9 100644
--- a/src/backend/access/heap/heapam.c
+++ b/src/backend/access/heap/heapam.c
@@ -3190,7 +3190,7 @@ 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_HOT_BLOCKING);
+	hot_attrs = RelationGetIndexAttrBitmap(relation, INDEX_ATTR_BITMAP_ALL);
 	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 06131f23d4b..9b730f303fb 100644
--- a/src/backend/access/nbtree/nbtree.c
+++ b/src/backend/access/nbtree/nbtree.c
@@ -114,7 +114,6 @@ 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 a171ca8a08a..2c661fcf96f 100644
--- a/src/backend/access/spgist/spgutils.c
+++ b/src/backend/access/spgist/spgutils.c
@@ -62,7 +62,6 @@ 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;