allow_dup_relfilenodeid_PoC.txt

diff --git a/src/backend/utils/cache/relfilenodemap.c b/src/backend/utils/cache/relfilenodemap.c
index 70c323c720..5d0b39a243 100644
--- a/src/backend/utils/cache/relfilenodemap.c
+++ b/src/backend/utils/cache/relfilenodemap.c
@@ -130,7 +130,8 @@ InitializeRelfilenodeMap(void)
 
 /*
  * Map a relation's (tablespace, filenode) to a relation's oid and cache the
- * result.
+ * result.  If both non-temprary and temprary reltations are found, persistent
+ * one is choosed.
  *
  * Returns InvalidOid if no relation matching the criteria could be found.
  */
@@ -183,6 +184,8 @@ RelidByRelfilenode(Oid reltablespace, Oid relfilenode)
 	}
 	else
 	{
+		bool is_temp = false;
+
 		/*
 		 * Not a shared table, could either be a plain relation or a
 		 * non-shared, nailed one, like e.g. pg_class.
@@ -212,14 +215,25 @@ RelidByRelfilenode(Oid reltablespace, Oid relfilenode)
 			Form_pg_class classform = (Form_pg_class) GETSTRUCT(ntp);
 
 			if (found)
-				elog(ERROR,
-					 "unexpected duplicate for tablespace %u, relfilenode %u",
-					 reltablespace, relfilenode);
+			{
+				/* check if the same entry for the same persistency exists */
+				if (is_temp ?
+					classform->relpersistence == RELPERSISTENCE_TEMP :
+					classform->relpersistence != RELPERSISTENCE_TEMP)
+					elog(ERROR,
+						 "unexpected duplicate for tablespace %u, relfilenode %u",
+						 reltablespace, relfilenode);
+
+				/* prioritize non-temporary if both are found */
+				if (!is_temp)
+					continue;
+			}
 			found = true;
 
 			Assert(classform->reltablespace == reltablespace);
 			Assert(classform->relfilenode == relfilenode);
 			relid = classform->oid;
+			is_temp = (classform->relpersistence == RELPERSISTENCE_TEMP);
 		}
 
 		systable_endscan(scandesc);