Report index name on CLUSTER failure. Also, suggest ALTER TABLE

WITHOUT CLUSTER for cluster failure of a single table in a full db
cluster.

3 files changed, 18 insertions, 11 deletions

diff --git a/src/backend/commands/cluster.c b/src/backend/commands/cluster.c
index 9979afaab8..9e31b4cba5 100644
--- a/src/backend/commands/cluster.c
+++ b/src/backend/commands/cluster.c
@@ -292,7 +292,7 @@ cluster_rel(RelToCluster *rvtc, bool recheck)
 	OldHeap = heap_open(rvtc->tableOid, AccessExclusiveLock);
 
 	/* Check index is valid to cluster on */
-	check_index_is_clusterable(OldHeap, rvtc->indexOid);
+	check_index_is_clusterable(OldHeap, rvtc->indexOid, recheck);
 
 	/* rebuild_relation does all the dirty work */
 	rebuild_relation(OldHeap, rvtc->indexOid);
@@ -309,7 +309,7 @@ cluster_rel(RelToCluster *rvtc, bool recheck)
  * definition can't change under us.
  */
 void
-check_index_is_clusterable(Relation OldHeap, Oid indexOid)
+check_index_is_clusterable(Relation OldHeap, Oid indexOid, bool recheck)
 {
 	Relation	OldIndex;
 
@@ -336,7 +336,9 @@ check_index_is_clusterable(Relation OldHeap, Oid indexOid)
 	if (!heap_attisnull(OldIndex->rd_indextuple, Anum_pg_index_indpred))
 		ereport(ERROR,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-				 errmsg("cannot cluster on partial index")));
+				 errmsg("cannot cluster on partial index \"%s\"",
+						RelationGetRelationName(OldIndex))));
+	
 	if (!OldIndex->rd_am->amindexnulls)
 	{
 		AttrNumber	colno;
@@ -354,21 +356,25 @@ check_index_is_clusterable(Relation OldHeap, Oid indexOid)
 			if (!OldHeap->rd_att->attrs[colno - 1]->attnotnull)
 				ereport(ERROR,
 						(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-						 errmsg("cannot cluster when index access method does not handle null values"),
-						 errhint("You may be able to work around this by marking column \"%s\" NOT NULL.",
-				  NameStr(OldHeap->rd_att->attrs[colno - 1]->attname))));
+						 errmsg("cannot cluster on index \"%s\" because access method\n"
+								"does not handle null values",
+							  RelationGetRelationName(OldIndex)),
+						 errhint("You may be able to work around this by marking column \"%s\" NOT NULL%s",
+							NameStr(OldHeap->rd_att->attrs[colno - 1]->attname),
+							recheck ? ",\nor use ALTER TABLE ... SET WITHOUT CLUSTER to remove the cluster\n"
+									"specification from the table." : ".")));
 		}
 		else if (colno < 0)
 		{
 			/* system column --- okay, always non-null */
 		}
 		else
-		{
 			/* index expression, lose... */
 			ereport(ERROR,
 					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-					 errmsg("cannot cluster on expressional index when index access method does not handle null values")));
-		}
+					 errmsg("cannot cluster on expressional index \"%s\" because its index access\n"
+							"method does not handle null values",
+						RelationGetRelationName(OldIndex))));
 	}
 
 	/*
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 8ea8b25428..b76c28baef 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -5464,7 +5464,7 @@ ATExecClusterOn(Relation rel, const char *indexName)
 						indexName, RelationGetRelationName(rel))));
 
 	/* Check index is valid to cluster on */
-	check_index_is_clusterable(rel, indexOid);
+	check_index_is_clusterable(rel, indexOid, false);
 
 	/* And do the work */
 	mark_index_clustered(rel, indexOid);
diff --git a/src/include/commands/cluster.h b/src/include/commands/cluster.h
index 185b324eaf..674fd6795f 100644
--- a/src/include/commands/cluster.h
+++ b/src/include/commands/cluster.h
@@ -19,7 +19,8 @@
 
 extern void cluster(ClusterStmt *stmt);
 
-extern void check_index_is_clusterable(Relation OldHeap, Oid indexOid);
+extern void check_index_is_clusterable(Relation OldHeap, Oid indexOid,
+			  bool recheck);
 extern void mark_index_clustered(Relation rel, Oid indexOid);
 extern Oid make_new_heap(Oid OIDOldHeap, const char *NewName,
 			  Oid NewTableSpace);