Subject: [PATCH v2 3/3] Implement REINDEX of partitioned tables/indexes

From: Justin Pryzby <[email-masked]>
Date: Sun, 7 Jun 2020 15:59:54 -0500

---
 doc/src/sgml/ref/reindex.sgml              |   5 -
 src/backend/catalog/index.c                |   7 +-
 src/backend/commands/indexcmds.c           | 119 +++++++++++++--------
 src/backend/tcop/utility.c                 |   6 +-
 src/include/commands/defrem.h              |   6 +-
 src/test/regress/expected/create_index.out |  10 +-
 src/test/regress/sql/create_index.sql      |   4 +-
 7 files changed, 89 insertions(+), 68 deletions(-)

diff --git a/doc/src/sgml/ref/reindex.sgml b/doc/src/sgml/ref/reindex.sgml
index aac5d5be23..e2e32b3ba0 100644
--- a/doc/src/sgml/ref/reindex.sgml
+++ b/doc/src/sgml/ref/reindex.sgml
@@ -258,11 +258,6 @@ REINDEX [ ( <replaceable class="parameter">option</replaceable> [, ...] ) ] { IN
    can always reindex anything.
   </para>
 
-  <para>
-   Reindexing partitioned tables or partitioned indexes is not supported.
-   Each individual partition can be reindexed separately instead.
-  </para>
-
   <refsect2 id="sql-reindex-concurrently" xreflabel="Rebuilding Indexes Concurrently">
    <title>Rebuilding Indexes Concurrently</title>
 
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index cdc01c49c9..b82d122353 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -3688,12 +3688,7 @@ reindex_relation(Oid relid, int flags, int options)
 	 */
 	rel = table_open(relid, ShareLock);
 
-	/*
-	 * This may be useful when implemented someday; but that day is not today.
-	 * For now, avoid erroring out when called in a multi-table context
-	 * (REINDEX SCHEMA) and happen to come across a partitioned table.  The
-	 * partitions may be reindexed on their own anyway.
-	 */
+	/* Avoid erroring out */
 	if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
 	{
 		ereport(WARNING,
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 344cabaf52..66be1c9c8c 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -88,7 +88,8 @@ static List *ChooseIndexColumnNames(List *indexElems);
 static void RangeVarCallbackForReindexIndex(const RangeVar *relation,
 											Oid relId, Oid oldRelId, void *arg);
 static bool ReindexRelationConcurrently(Oid relationOid, int options);
-static void ReindexPartitionedIndex(Relation parentIdx);
+static void ReindexPartitionedRel(Oid reloid, int options, bool concurrent,
+		bool isTopLevel);
 static void update_relispartition(Oid relationId, bool newval);
 static bool CompareOpclassOptions(Datum *opts1, Datum *opts2, int natts);
 
@@ -2428,11 +2429,10 @@ ChooseIndexColumnNames(List *indexElems)
  *		Recreate a specific index.
  */
 void
-ReindexIndex(RangeVar *indexRelation, int options, bool concurrent)
+ReindexIndex(RangeVar *indexRelation, int options, bool concurrent, bool isTopLevel)
 {
 	struct ReindexIndexCallbackState state;
 	Oid			indOid;
-	Relation	irel;
 	char		persistence;
 
 	/*
@@ -2453,22 +2453,10 @@ ReindexIndex(RangeVar *indexRelation, int options, bool concurrent)
 									  RangeVarCallbackForReindexIndex,
 									  &state);
 
-	/*
-	 * Obtain the current persistence of the existing index.  We already hold
-	 * lock on the index.
-	 */
-	irel = index_open(indOid, NoLock);
-
-	if (irel->rd_rel->relkind == RELKIND_PARTITIONED_INDEX)
-	{
-		ReindexPartitionedIndex(irel);
-		return;
-	}
-
-	persistence = irel->rd_rel->relpersistence;
-	index_close(irel, NoLock);
-
-	if (concurrent && persistence != RELPERSISTENCE_TEMP)
+	persistence = get_rel_persistence(indOid);
+	if (get_rel_relkind(indOid) == RELKIND_PARTITIONED_INDEX)
+		ReindexPartitionedRel(indOid, options, concurrent, isTopLevel);
+	else if (concurrent && persistence != RELPERSISTENCE_TEMP)
 		ReindexRelationConcurrently(indOid, options);
 	else
 		reindex_index(indOid, false, persistence,
@@ -2550,7 +2538,7 @@ RangeVarCallbackForReindexIndex(const RangeVar *relation,
  *		Recreate all indexes of a table (and of its toast table, if any)
  */
 Oid
-ReindexTable(RangeVar *relation, int options, bool concurrent)
+ReindexTable(RangeVar *relation, int options, bool concurrent, bool isTopLevel)
 {
 	Oid			heapOid;
 	bool		result;
@@ -2568,7 +2556,9 @@ ReindexTable(RangeVar *relation, int options, bool concurrent)
 									   0,
 									   RangeVarCallbackOwnsTable, NULL);
 
-	if (concurrent && get_rel_persistence(heapOid) != RELPERSISTENCE_TEMP)
+	if (get_rel_relkind(heapOid) == RELKIND_PARTITIONED_TABLE)
+		ReindexPartitionedRel(heapOid, options, concurrent, isTopLevel);
+	else if (concurrent && get_rel_persistence(heapOid) != RELPERSISTENCE_TEMP)
 	{
 		result = ReindexRelationConcurrently(heapOid, options);
 
@@ -2696,11 +2686,8 @@ ReindexMultipleTables(const char *objectName, ReindexObjectType objectKind,
 		 * Only regular tables and matviews can have indexes, so ignore any
 		 * other kind of relation.
 		 *
-		 * It is tempting to also consider partitioned tables here, but that
-		 * has the problem that if the children are in the same schema, they
-		 * would be processed twice.  Maybe we could have a separate list of
-		 * partitioned tables, and expand that afterwards into relids,
-		 * ignoring any duplicates.
+		 * Partitioned tables/indexes are skipped but matching leaf
+		 * partitions are processed.
 		 */
 		if (classtuple->relkind != RELKIND_RELATION &&
 			classtuple->relkind != RELKIND_MATVIEW)
@@ -2813,8 +2800,7 @@ ReindexMultipleTables(const char *objectName, ReindexObjectType objectKind,
  * view.  For tables and materialized views, all its indexes will be rebuilt,
  * excluding invalid indexes and any indexes used in exclusion constraints,
  * but including its associated toast table indexes.  For indexes, the index
- * itself will be rebuilt.  If 'relationOid' belongs to a partitioned table
- * then we issue a warning to mention these are not yet supported.
+ * itself will be rebuilt.
  *
  * The locks taken on parent tables and involved indexes are kept until the
  * transaction is committed, at which point a session lock is taken on each
@@ -3018,13 +3004,6 @@ ReindexRelationConcurrently(Oid relationOid, int options)
 				MemoryContextSwitchTo(oldcontext);
 				break;
 			}
-		case RELKIND_PARTITIONED_TABLE:
-			/* see reindex_relation() */
-			ereport(WARNING,
-					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-					 errmsg("REINDEX of partitioned tables is not yet implemented, skipping \"%s\"",
-							get_rel_name(relationOid))));
-			return false;
 		default:
 			/* Return error if type of relation is not supported */
 			ereport(ERROR,
@@ -3486,17 +3465,71 @@ ReindexRelationConcurrently(Oid relationOid, int options)
 }
 
 /*
- *	ReindexPartitionedIndex
- *		Reindex each child of the given partitioned index.
- *
- * Not yet implemented.
+ *	ReindexPartitionedRel
+ *		Reindex each child of the given partitioned relation.
  */
 static void
-ReindexPartitionedIndex(Relation parentIdx)
+ReindexPartitionedRel(Oid reloid, int options, bool concurrent, bool isTopLevel)
 {
-	ereport(ERROR,
-			(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-			 errmsg("REINDEX is not yet implemented for partitioned indexes")));
+	MemoryContext oldcontext, reindex_context;
+	List		*inhoids;
+	ListCell	 *lc;
+
+	/*
+	 * This cannot run inside a user transaction block; if
+	 * we were inside a transaction, then its commit- and
+	 * start-transaction-command calls would not have the
+	 * intended effect!
+	 */
+	PreventInTransactionBlock(isTopLevel,
+		"REINDEX of partitioned relations"); // XXX
+
+	/*
+	 * Create list of children in longlived context, since we process each
+	 * child in a separate transaction
+	 */
+	reindex_context = AllocSetContextCreate(PortalContext, "Reindex",
+			ALLOCSET_DEFAULT_SIZES);
+	oldcontext = MemoryContextSwitchTo(reindex_context);
+	inhoids = find_all_inheritors(reloid, NoLock, NULL);
+	MemoryContextSwitchTo(oldcontext);
+
+	foreach (lc, inhoids)
+	{
+		Oid	inhrelid = lfirst_oid(lc);
+
+		PopActiveSnapshot();
+		CommitTransactionCommand();
+
+		StartTransactionCommand();
+		/* functions in indexes may want a snapshot set */
+		PushActiveSnapshot(GetTransactionSnapshot());
+
+		switch (get_rel_relkind(inhrelid))
+		{
+		case RELKIND_PARTITIONED_INDEX:
+		case RELKIND_PARTITIONED_TABLE:
+			/*
+			 * We have a full list of direct and indirect children, so skip
+			 * partitioned relations and just handle their children.
+			 */
+			continue;
+		case RELKIND_INDEX:
+			reindex_index(inhrelid, false, get_rel_persistence(inhrelid),
+						  options | REINDEXOPT_REPORT_PROGRESS);
+			break;
+		case RELKIND_RELATION:
+			(void) reindex_relation(inhrelid,
+									  REINDEX_REL_PROCESS_TOAST |
+									  REINDEX_REL_CHECK_CONSTRAINTS,
+									  options | REINDEXOPT_REPORT_PROGRESS);
+			break;
+		}
+	}
+
+	PopActiveSnapshot();
+	CommitTransactionCommand();
+	StartTransactionCommand();
 }
 
 /*
diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c
index 97cbaa3072..e72bbbb425 100644
--- a/src/backend/tcop/utility.c
+++ b/src/backend/tcop/utility.c
@@ -926,10 +926,12 @@ standard_ProcessUtility(PlannedStmt *pstmt,
 				switch (stmt->kind)
 				{
 					case REINDEX_OBJECT_INDEX:
-						ReindexIndex(stmt->relation, stmt->options, stmt->concurrent);
+						ReindexIndex(stmt->relation, stmt->options,
+								stmt->concurrent, isTopLevel);
 						break;
 					case REINDEX_OBJECT_TABLE:
-						ReindexTable(stmt->relation, stmt->options, stmt->concurrent);
+						ReindexTable(stmt->relation, stmt->options,
+								stmt->concurrent, isTopLevel);
 						break;
 					case REINDEX_OBJECT_SCHEMA:
 					case REINDEX_OBJECT_SYSTEM:
diff --git a/src/include/commands/defrem.h b/src/include/commands/defrem.h
index c77c9a6ed5..eea6b01791 100644
--- a/src/include/commands/defrem.h
+++ b/src/include/commands/defrem.h
@@ -34,8 +34,10 @@ extern ObjectAddress DefineIndex(Oid relationId,
 								 bool check_not_in_use,
 								 bool skip_build,
 								 bool quiet);
-extern void ReindexIndex(RangeVar *indexRelation, int options, bool concurrent);
-extern Oid	ReindexTable(RangeVar *relation, int options, bool concurrent);
+extern void ReindexIndex(RangeVar *indexRelation, int options, bool concurrent,
+						bool isTopLevel);
+extern Oid	ReindexTable(RangeVar *relation, int options, bool concurrent,
+						bool isTopLevel);
 extern void ReindexMultipleTables(const char *objectName, ReindexObjectType objectKind,
 								  int options, bool concurrent);
 extern char *makeObjectName(const char *name1, const char *name2,
diff --git a/src/test/regress/expected/create_index.out b/src/test/regress/expected/create_index.out
index e3e6634d7e..8ad103d80b 100644
--- a/src/test/regress/expected/create_index.out
+++ b/src/test/regress/expected/create_index.out
@@ -2196,18 +2196,12 @@ SELECT relid, parentrelid, level FROM pg_partition_tree('concur_reindex_part_ind
  concur_reindex_part_index_0_2 | concur_reindex_part_index_0 |     2
 (5 rows)
 
--- REINDEX fails for partitioned indexes
+-- REINDEX for partitioned indexes
 REINDEX INDEX concur_reindex_part_index_10;
-ERROR:  REINDEX is not yet implemented for partitioned indexes
 REINDEX INDEX CONCURRENTLY concur_reindex_part_index_10;
-ERROR:  REINDEX is not yet implemented for partitioned indexes
--- REINDEX is a no-op for partitioned tables
+-- REINDEX for partitioned tables
 REINDEX TABLE concur_reindex_part_10;
-WARNING:  REINDEX of partitioned tables is not yet implemented, skipping "concur_reindex_part_10"
-NOTICE:  table "concur_reindex_part_10" has no indexes to reindex
 REINDEX TABLE CONCURRENTLY concur_reindex_part_10;
-WARNING:  REINDEX of partitioned tables is not yet implemented, skipping "concur_reindex_part_10"
-NOTICE:  table "concur_reindex_part_10" has no indexes that can be reindexed concurrently
 SELECT relid, parentrelid, level FROM pg_partition_tree('concur_reindex_part_index')
   ORDER BY relid, level;
              relid             |         parentrelid         | level 
diff --git a/src/test/regress/sql/create_index.sql b/src/test/regress/sql/create_index.sql
index f3667bacdc..cd7f13b307 100644
--- a/src/test/regress/sql/create_index.sql
+++ b/src/test/regress/sql/create_index.sql
@@ -903,10 +903,10 @@ CREATE INDEX concur_reindex_part_index_0_2 ON ONLY concur_reindex_part_0_2 (c1);
 ALTER INDEX concur_reindex_part_index_0 ATTACH PARTITION concur_reindex_part_index_0_2;
 SELECT relid, parentrelid, level FROM pg_partition_tree('concur_reindex_part_index')
   ORDER BY relid, level;
--- REINDEX fails for partitioned indexes
+-- REINDEX for partitioned indexes
 REINDEX INDEX concur_reindex_part_index_10;
 REINDEX INDEX CONCURRENTLY concur_reindex_part_index_10;
--- REINDEX is a no-op for partitioned tables
+-- REINDEX for partitioned tables
 REINDEX TABLE concur_reindex_part_10;
 REINDEX TABLE CONCURRENTLY concur_reindex_part_10;
 SELECT relid, parentrelid, level FROM pg_partition_tree('concur_reindex_part_index')
-- 
2.17.0

--JwB53PgKC5A7+0Ej--