Add if_attached argument to detach_data_node()

This change makes detach_data_node() function consistent with
other data node management functions by adding missing
if_attach argument.

The function will not show an error in case if data node is not
attached and if_attached is set to true.

Issue: #2506

sql/ddl_api.sql

@@ -179,6 +179,7 @@ AS '@MODULE_PATHNAME@', 'ts_data_node_attach' LANGUAGE C VOLATILE;
 CREATE OR REPLACE FUNCTION detach_data_node(
     node_name              NAME,
     hypertable             REGCLASS = NULL,
+    if_attached            BOOLEAN = FALSE,
     force                  BOOLEAN = FALSE,
     repartition            BOOLEAN = TRUE
 ) RETURNS INTEGER

sql/updates/latest-dev.sql

@@ -0,0 +1,2 @@
+
+DROP FUNCTION IF EXISTS detach_data_node(name,regclass,boolean,boolean);

tsl/src/data_node.c

@@ -1133,14 +1133,14 @@ data_node_detach_hypertable_data_nodes(const char *node_name, List *hypertable_d
 }
 
 static HypertableDataNode *
-get_hypertable_data_node(Oid table_id, const char *node_name, bool ownercheck)
+get_hypertable_data_node(Oid table_id, const char *node_name, bool owner_check, bool attach_check)
 {
 	HypertableDataNode *hdn = NULL;
 	Cache *hcache = ts_hypertable_cache_pin();
 	Hypertable *ht = ts_hypertable_cache_get_entry(hcache, table_id, CACHE_FLAG_NONE);
 	ListCell *lc;
 
-	if (ownercheck)
+	if (owner_check)
 		ts_hypertable_permissions_check(table_id, GetUserId());
 
 	foreach (lc, ht->data_nodes)
@@ -1153,11 +1153,21 @@ get_hypertable_data_node(Oid table_id, const char *node_name, bool ownercheck)
 	}
 
 	if (hdn == NULL)
+	{
+		if (attach_check)
 			ereport(ERROR,
 					(errcode(ERRCODE_TS_DATA_NODE_NOT_ATTACHED),
 					 errmsg("data node \"%s\" is not attached to hypertable \"%s\"",
 							node_name,
 							get_rel_name(table_id))));
+		else
+			ereport(NOTICE,
+					(errcode(ERRCODE_TS_DATA_NODE_NOT_ATTACHED),
+					 errmsg("data node \"%s\" is not attached to hypertable \"%s\", "
+							"skipping",
+							node_name,
+							get_rel_name(table_id))));
+	}
 
 	ts_cache_release(hcache);
 
@@ -1180,7 +1190,7 @@ data_node_block_or_allow_new_chunks(const char *node_name, Oid const table_id, b
 		/* Early abort on missing hypertable permissions */
 		ts_hypertable_permissions_check(table_id, GetUserId());
 		hypertable_data_nodes =
-			list_make1(get_hypertable_data_node(table_id, server->servername, true));
+			list_make1(get_hypertable_data_node(table_id, server->servername, true, true));
 	}
 	else
 	{
@@ -1226,8 +1236,9 @@ data_node_detach(PG_FUNCTION_ARGS)
 	const char *node_name = PG_ARGISNULL(0) ? NULL : NameStr(*PG_GETARG_NAME(0));
 	Oid table_id = PG_ARGISNULL(1) ? InvalidOid : PG_GETARG_OID(1);
 	bool all_hypertables = PG_ARGISNULL(1);
-	bool force = PG_ARGISNULL(2) ? InvalidOid : PG_GETARG_OID(2);
+	bool if_attached = PG_ARGISNULL(2) ? false : PG_GETARG_BOOL(2);
-	bool repartition = PG_ARGISNULL(3) ? false : PG_GETARG_BOOL(3);
+	bool force = PG_ARGISNULL(3) ? InvalidOid : PG_GETARG_OID(3);
+	bool repartition = PG_ARGISNULL(4) ? false : PG_GETARG_BOOL(4);
 	int removed = 0;
 	List *hypertable_data_nodes = NIL;
 	ForeignServer *server;
@@ -1239,10 +1250,14 @@ data_node_detach(PG_FUNCTION_ARGS)
 
 	if (OidIsValid(table_id))
 	{
+		HypertableDataNode *node;
+
 		/* Early abort on missing hypertable permissions */
 		ts_hypertable_permissions_check(table_id, GetUserId());
-		hypertable_data_nodes =
+
-			list_make1(get_hypertable_data_node(table_id, server->servername, true));
+		node = get_hypertable_data_node(table_id, server->servername, true, !if_attached);
+		if (node)
+			hypertable_data_nodes = list_make1(node);
 	}
 	else
 	{

tsl/test/expected/data_node.out

@@ -1026,6 +1026,8 @@ ERROR:  detaching data node "data_node_1" failed because it contains chunks for
 -- can't detach already detached data node
 SELECT * FROM detach_data_node('data_node_2', 'disttable_2');
 ERROR:  data node "data_node_2" is not attached to hypertable "disttable_2"
+SELECT * FROM detach_data_node('data_node_2', 'disttable_2', if_attached => false);
+ERROR:  data node "data_node_2" is not attached to hypertable "disttable_2"
 -- can't detach b/c of replication factor for disttable_2
 SELECT * FROM detach_data_node('data_node_3', 'disttable_2');
 ERROR:  detaching data node "data_node_3" risks making new data for hypertable "disttable_2" under-replicated
@@ -1033,6 +1035,14 @@ ERROR:  detaching data node "data_node_3" risks making new data for hypertable "
 SELECT * FROM detach_data_node('data_node_3', 'devices');
 ERROR:  table "devices" is not a hypertable
 \set ON_ERROR_STOP 1
+-- do nothing if node is not attached
+SELECT * FROM detach_data_node('data_node_2', 'disttable_2', if_attached => true);
+NOTICE:  data node "data_node_2" is not attached to hypertable "disttable_2", skipping
+ detach_data_node 
+------------------
+                0
+(1 row)
+
 -- force detach data node to become under-replicated for new data
 SELECT * FROM detach_data_node('data_node_3', 'disttable_2', force => true);
 WARNING:  new data for hypertable "disttable_2" will be under-replicated due to detaching data node "data_node_3"
@@ -1127,7 +1137,7 @@ ORDER BY foreign_table_name;
 --------------------+---------------------
 (0 rows)
 
-SELECT * FROM detach_data_node('data_node_2', 'disttable', true);
+SELECT * FROM detach_data_node('data_node_2', 'disttable', force => true);
 WARNING:  new data for hypertable "disttable" will be under-replicated due to detaching data node "data_node_2"
 NOTICE:  the number of partitions in dimension "device" was decreased to 1
  detach_data_node 

tsl/test/sql/data_node.sql

@@ -508,12 +508,16 @@ SELECT * FROM detach_data_node(NULL, 'disttable');
 SELECT * FROM detach_data_node('data_node_1');
 -- can't detach already detached data node
 SELECT * FROM detach_data_node('data_node_2', 'disttable_2');
+SELECT * FROM detach_data_node('data_node_2', 'disttable_2', if_attached => false);
 -- can't detach b/c of replication factor for disttable_2
 SELECT * FROM detach_data_node('data_node_3', 'disttable_2');
 -- can't detach non hypertable
 SELECT * FROM detach_data_node('data_node_3', 'devices');
 \set ON_ERROR_STOP 1
 
+-- do nothing if node is not attached
+SELECT * FROM detach_data_node('data_node_2', 'disttable_2', if_attached => true);
+
 -- force detach data node to become under-replicated for new data
 SELECT * FROM detach_data_node('data_node_3', 'disttable_2', force => true);
 
@@ -547,7 +551,7 @@ SELECT foreign_table_name, foreign_server_name
 FROM information_schema.foreign_tables
 ORDER BY foreign_table_name;
 
-SELECT * FROM detach_data_node('data_node_2', 'disttable', true);
+SELECT * FROM detach_data_node('data_node_2', 'disttable', force => true);
 
 -- Let's add more data nodes
 SET ROLE :ROLE_CLUSTER_SUPERUSER;