Subject: [PATCH v4 4/5] Invalidate parent index cluster on attach

From: Justin Pryzby <[email-masked]>
Date: Thu, 5 Nov 2020 19:11:41 -0600

---
 src/backend/commands/indexcmds.c      | 21 +++++++++++++++++++++
 src/test/regress/expected/cluster.out | 14 ++++++++++++++
 src/test/regress/sql/cluster.sql      |  5 +++++
 3 files changed, 40 insertions(+)

diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 538055c9a0..fd8b2d56d2 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -3775,6 +3775,27 @@ IndexSetParentIndex(Relation partitionIdx, Oid parentOid)
 	/* set relispartition correctly on the partition */
 	update_relispartition(partRelid, OidIsValid(parentOid));
 
+	/*
+	 * If the attached index is not clustered, invalidate cluster mark on
+	 * any parents
+	 */
+	if ((OidIsValid(parentOid) && get_index_isclustered(parentOid)) ||
+			get_index_isclustered(partRelid))
+	{
+		Relation indrel;
+
+		/* Make relispartition visible */
+		CommandCounterIncrement();
+
+		indrel = table_open(IndexGetRelation(partRelid, false),
+				ShareUpdateExclusiveLock);
+		mark_index_clustered(indrel,
+				get_index_isclustered(partRelid) ? partRelid : InvalidOid,
+				true);
+		table_close(indrel, ShareUpdateExclusiveLock);
+
+	}
+
 	if (fix_dependencies)
 	{
 		/*
diff --git a/src/test/regress/expected/cluster.out b/src/test/regress/expected/cluster.out
index 6d88978387..f0c962db75 100644
--- a/src/test/regress/expected/cluster.out
+++ b/src/test/regress/expected/cluster.out
@@ -567,6 +567,20 @@ Indexes:
     "clstrpart_idx" btree (a)
 Number of partitions: 3 (Use \d+ to list them.)
 
+-- Check that attaching an unclustered index marks the parent unclustered:
+ALTER TABLE clstrpart CLUSTER ON clstrpart_idx;
+CREATE TABLE clstrpart5 (LIKE clstrpart INCLUDING INDEXES);
+ALTER TABLE clstrpart ATTACH PARTITION clstrpart5 FOR VALUES FROM (40)TO(50);
+\d clstrpart
+       Partitioned table "public.clstrpart"
+ Column |  Type   | Collation | Nullable | Default 
+--------+---------+-----------+----------+---------
+ a      | integer |           |          | 
+Partition key: RANGE (a)
+Indexes:
+    "clstrpart_idx" btree (a)
+Number of partitions: 4 (Use \d+ to list them.)
+
 -- Test CLUSTER with external tuplesorting
 create table clstr_4 as select * from tenk1;
 create index cluster_sort on clstr_4 (hundred, thousand, tenthous);
diff --git a/src/test/regress/sql/cluster.sql b/src/test/regress/sql/cluster.sql
index c9bb204a93..ff7ffed6e4 100644
--- a/src/test/regress/sql/cluster.sql
+++ b/src/test/regress/sql/cluster.sql
@@ -239,6 +239,11 @@ CLUSTER clstrpart1 USING clstrpart1_idx_2;
 ALTER TABLE clstrpart CLUSTER ON clstrpart_idx;
 ALTER TABLE clstrpart1 SET WITHOUT CLUSTER;
 \d clstrpart
+-- Check that attaching an unclustered index marks the parent unclustered:
+ALTER TABLE clstrpart CLUSTER ON clstrpart_idx;
+CREATE TABLE clstrpart5 (LIKE clstrpart INCLUDING INDEXES);
+ALTER TABLE clstrpart ATTACH PARTITION clstrpart5 FOR VALUES FROM (40)TO(50);
+\d clstrpart
 
 -- Test CLUSTER with external tuplesorting
 
-- 
2.17.0

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 filename="v4-0005-Preserve-indisclustered-on-children-of-clustered-.patch"