Subject: [PATCH] fix

From: Justin Pryzby <[email-masked]>
Date: Sun, 10 Jan 2021 15:41:43 -0600

---
 src/backend/commands/tablecmds.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index d7b9c63e5f..144c27c303 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -17131,6 +17131,7 @@ ATExecDetachPartition(List **wqueue, AlteredTableInfo *tab, Relation rel,
 		Oid		partrelid,
 				parentrelid;
 		LOCKTAG		tag;
+		LockRelId	partlockrelid;
 		char   *parentrelname;
 		char   *partrelname;
 
@@ -17162,6 +17163,10 @@ ATExecDetachPartition(List **wqueue, AlteredTableInfo *tab, Relation rel,
 		table_close(rel, NoLock);
 		tab->rel = NULL;
 
+		partlockrelid.relId = parentrelid;
+		partlockrelid.dbId = MyDatabaseId;
+		LockRelationIdForSession(&partlockrelid, ShareUpdateExclusiveLock);
+
 		/* Make updated catalog entry visible */
 		PopActiveSnapshot();
 		CommitTransactionCommand();
@@ -17204,7 +17209,7 @@ ATExecDetachPartition(List **wqueue, AlteredTableInfo *tab, Relation rel,
 					 errmsg("partition \"%s\" was removed concurrently", partrelname)));
 
 		tab->rel = rel;
-
+		UnlockRelationIdForSession(&partlockrelid, ShareUpdateExclusiveLock);
 	}
 
 	/* Do the final part of detaching */
@@ -17444,7 +17449,10 @@ DetachAddConstraintIfNeeded(List **wqueue, Relation partRel)
 	TupleDesc	td = RelationGetDescr(partRel);
 	Constraint *n;
 
-	constraintExpr = make_ands_explicit(RelationGetPartitionQual(partRel));
+	List *l = RelationGetPartitionQual(partRel);
+	Assert(partRel->rd_rel->relispartition);
+	Assert(l != NIL);
+	constraintExpr = make_ands_explicit(l);
 
 	/* If an identical constraint exists, we don't need to create one */
 	if (td->constr && td->constr->num_check > 0)
-- 
2.17.0

--kR3zbvD4cgoYnS/6--