From e81d25a7be8844e46b256aa69c5207766f0588c9 Mon Sep 17 00:00:00 2001
From: Marco Slot <marco.slot@gmail.com>
Date: Wed, 2 Jun 2021 13:51:39 +0200
Subject: [PATCH] Refactor RelationIsAKnownShard to remove onlySearchPath
 argument

---
 .../worker/worker_shard_visibility.c          | 42 ++++++++++---------
 .../distributed/worker_shard_visibility.h     |  2 +-
 2 files changed, 24 insertions(+), 20 deletions(-)

diff --git a/src/backend/distributed/worker/worker_shard_visibility.c b/src/backend/distributed/worker/worker_shard_visibility.c
index 53132d1db..05b8e0bad 100644
--- a/src/backend/distributed/worker/worker_shard_visibility.c
+++ b/src/backend/distributed/worker/worker_shard_visibility.c
@@ -43,9 +43,19 @@ relation_is_a_known_shard(PG_FUNCTION_ARGS)
 	CheckCitusVersion(ERROR);
 
 	Oid relationId = PG_GETARG_OID(0);
-	bool onlySearchPath = true;
 
-	PG_RETURN_BOOL(RelationIsAKnownShard(relationId, onlySearchPath));
+	if (!RelationIsVisible(relationId))
+	{
+		/*
+		 * Relation is not on the search path.
+		 *
+		 * TODO: it might be nicer to add a separate check in the
+		 * citus_shards_on_worker views where this UDF is used.
+		 */
+		PG_RETURN_BOOL(false);
+	}
+
+	PG_RETURN_BOOL(RelationIsAKnownShard(relationId));
 }
 
 
@@ -61,7 +71,6 @@ citus_table_is_visible(PG_FUNCTION_ARGS)
 
 	Oid relationId = PG_GETARG_OID(0);
 	char relKind = '\0';
-	bool onlySearchPath = true;
 
 	/*
 	 * We don't want to deal with not valid/existing relations
@@ -72,7 +81,13 @@ citus_table_is_visible(PG_FUNCTION_ARGS)
 		PG_RETURN_NULL();
 	}
 
-	if (RelationIsAKnownShard(relationId, onlySearchPath))
+	if (!RelationIsVisible(relationId))
+	{
+		/* relation is not on the search path */
+		PG_RETURN_BOOL(false);
+	}
+
+	if (RelationIsAKnownShard(relationId))
 	{
 		/*
 		 * If the input relation is an index we simply replace the
@@ -106,9 +121,7 @@ citus_table_is_visible(PG_FUNCTION_ARGS)
 void
 ErrorIfRelationIsAKnownShard(Oid relationId)
 {
-	/* search the relation in all schemas */
-	bool onlySearchPath = false;
-	if (!RelationIsAKnownShard(relationId, onlySearchPath))
+	if (!RelationIsAKnownShard(relationId))
 	{
 		return;
 	}
@@ -133,9 +146,7 @@ ErrorIfIllegallyChangingKnownShard(Oid relationId)
 		return;
 	}
 
-	/* search the relation in all schemas */
-	bool onlySearchPath = true;
-	if (RelationIsAKnownShard(relationId, onlySearchPath))
+	if (RelationIsAKnownShard(relationId))
 	{
 		const char *relationName = get_rel_name(relationId);
 		ereport(ERROR, (errmsg("cannot modify \"%s\" because it is a shard of "
@@ -150,14 +161,13 @@ ErrorIfIllegallyChangingKnownShard(Oid relationId)
 
 /*
  * RelationIsAKnownShard gets a relationId, check whether it's a shard of
- * any distributed table. If onlySearchPath is true, then it searches
- * the current search path.
+ * any distributed table.
  *
  * We can only do that in MX since both the metadata and tables are only
  * present there.
  */
 bool
-RelationIsAKnownShard(Oid shardRelationId, bool onlySearchPath)
+RelationIsAKnownShard(Oid shardRelationId)
 {
 	bool missingOk = true;
 	char relKind = '\0';
@@ -191,12 +201,6 @@ RelationIsAKnownShard(Oid shardRelationId, bool onlySearchPath)
 	}
 	relation_close(relation, NoLock);
 
-	/* we're not interested in the relations that are not in the search path */
-	if (!RelationIsVisible(shardRelationId) && onlySearchPath)
-	{
-		return false;
-	}
-
 	/*
 	 * If the input relation is an index we simply replace the
 	 * relationId with the corresponding relation to hide indexes
diff --git a/src/include/distributed/worker_shard_visibility.h b/src/include/distributed/worker_shard_visibility.h
index 85c48a758..c5c58d712 100644
--- a/src/include/distributed/worker_shard_visibility.h
+++ b/src/include/distributed/worker_shard_visibility.h
@@ -20,7 +20,7 @@ extern bool EnableManualChangesToShards;
 extern void ReplaceTableVisibleFunction(Node *inputNode);
 extern void ErrorIfRelationIsAKnownShard(Oid relationId);
 extern void ErrorIfIllegallyChangingKnownShard(Oid relationId);
-extern bool RelationIsAKnownShard(Oid shardRelationId, bool onlySearchPath);
+extern bool RelationIsAKnownShard(Oid shardRelationId);
 
 
 #endif /* WORKER_SHARD_VISIBILITY_H */