PG16: Prohibit use of multi-node

Since multi-node is not supported on PG16, add errors to multi-node
functions when run on this PostgreSQL version.

sql/updates/pre-update.sql

@@ -51,3 +51,35 @@ WHERE
   )
 ;
 
+-- ERROR if trying to update the extension on PG16 using Multi-Node
+DO $$
+DECLARE
+  data_nodes TEXT;
+  dist_hypertables TEXT;
+BEGIN
+  IF current_setting('server_version_num')::int >= 160000 THEN
+    SELECT string_agg(format('%I.%I', hypertable_schema, hypertable_name), ', ')
+    INTO dist_hypertables
+    FROM timescaledb_information.hypertables
+    WHERE is_distributed IS TRUE;
+
+    IF dist_hypertables IS NOT NULL THEN
+      RAISE USING
+        ERRCODE = 'feature_not_supported',
+        MESSAGE = 'cannot upgrade because multi-node is not supported on PostgreSQL >= 16',
+        DETAIL = 'The following distributed hypertables should be migrated to regular: '||dist_hypertables;
+    END IF;
+
+    SELECT string_agg(format('%I', node_name), ', ')
+    INTO data_nodes
+    FROM timescaledb_information.data_nodes;
+
+    IF data_nodes IS NOT NULL THEN
+      RAISE USING
+        ERRCODE = 'feature_not_supported',
+        MESSAGE = 'cannot upgrade because multi-node is not supported on PostgreSQL >= 16',
+        DETAIL = 'The following data nodes should be removed: '||data_nodes;
+    END IF;
+  END IF;
+END $$;
+

src/hypertable.c

@@ -68,6 +68,7 @@
 #include "debug_assert.h"
 #include "osm_callbacks.h"
 #include "error_utils.h"
+#include "compat/compat.h"
 
 Oid
 ts_rel_get_owner(Oid relid)
@@ -2046,6 +2047,18 @@ ts_hypertable_create(PG_FUNCTION_ARGS)
 Datum
 ts_hypertable_distributed_create(PG_FUNCTION_ARGS)
 {
+#if PG16_GE
+	ereport(ERROR,
+			(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+			 errmsg("distributed hypertable is not supported"),
+			 errdetail("Multi-node is not supported anymore on PostgreSQL >= 16."),
+			 errhint("Use the \"create_hypertable\" to create a regular hypertable instead.")));
+#else
+	ereport(WARNING,
+			(errcode(ERRCODE_WARNING_DEPRECATED_FEATURE),
+			 errmsg("distributed hypertable is deprecated"),
+			 errdetail("Multi-node is deprecated and will be removed in future releases.")));
+#endif
 	return ts_hypertable_create_time_prev(fcinfo, true);
 }
 

tsl/src/data_node.c

@@ -857,18 +857,52 @@ data_node_add_internal(PG_FUNCTION_ARGS, bool set_distid)
 Datum
 data_node_add(PG_FUNCTION_ARGS)
 {
+#if PG16_GE
+	ereport(ERROR,
+			(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+			 errmsg("adding data node is not supported"),
+			 errdetail("Multi-node is not supported anymore on PostgreSQL >= 16.")));
+#else
+	ereport(WARNING,
+			(errcode(ERRCODE_WARNING_DEPRECATED_FEATURE),
+			 errmsg("adding data node is deprecated"),
+			 errdetail("Multi-node is deprecated and will be removed in future releases.")));
+#endif
 	return data_node_add_internal(fcinfo, true);
 }
 
 Datum
 data_node_add_without_dist_id(PG_FUNCTION_ARGS)
 {
+#if PG16_GE
+	ereport(ERROR,
+			(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+			 errmsg("adding data node is not supported"),
+			 errdetail("Multi-node is not supported anymore on PostgreSQL >= 16.")));
+#else
+	ereport(WARNING,
+			(errcode(ERRCODE_WARNING_DEPRECATED_FEATURE),
+			 errmsg("adding data node is deprecated"),
+			 errdetail("Multi-node is deprecated and will be removed in future releases.")));
+#endif
 	return data_node_add_internal(fcinfo, false);
 }
 
 Datum
 data_node_attach(PG_FUNCTION_ARGS)
 {
+#if PG16_GE
+	ereport(ERROR,
+			(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+			 errmsg("attaching data node is not supported"),
+			 errdetail("Multi-node is not supported anymore on PostgreSQL >= 16.")));
+#else
+	ereport(WARNING,
+			(errcode(ERRCODE_WARNING_DEPRECATED_FEATURE),
+			 errmsg("attaching data node is deprecated"),
+			 errdetail("Multi-node is deprecated and will be removed in future releases.")));
+#endif
+
 	const char *node_name = PG_ARGISNULL(0) ? NULL : PG_GETARG_CSTRING(0);
 	Oid table_id = PG_GETARG_OID(1);
 	bool if_not_attached = PG_ARGISNULL(2) ? false : PG_GETARG_BOOL(2);
@@ -1404,6 +1438,18 @@ data_node_block_new_chunks(PG_FUNCTION_ARGS)
 Datum
 data_node_detach(PG_FUNCTION_ARGS)
 {
+#if PG16_GE
+	ereport(ERROR,
+			(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+			 errmsg("detaching data node is not supported"),
+			 errdetail("Multi-node is not supported anymore on PostgreSQL >= 16.")));
+#else
+	ereport(WARNING,
+			(errcode(ERRCODE_WARNING_DEPRECATED_FEATURE),
+			 errmsg("detaching data node is deprecated"),
+			 errdetail("Multi-node is deprecated and will be removed in future releases.")));
+#endif
+
 	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);
@@ -1601,6 +1647,18 @@ append_data_node_option(List *new_options, List **current_options, const char *n
 Datum
 data_node_alter(PG_FUNCTION_ARGS)
 {
+#if PG16_GE
+	ereport(ERROR,
+			(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+			 errmsg("altering data node is not supported"),
+			 errdetail("Multi-node is not supported anymore on PostgreSQL >= 16.")));
+#else
+	ereport(WARNING,
+			(errcode(ERRCODE_WARNING_DEPRECATED_FEATURE),
+			 errmsg("altering data node is deprecated"),
+			 errdetail("Multi-node is deprecated and will be removed in future releases.")));
+#endif
+
 	const char *node_name = PG_ARGISNULL(0) ? NULL : NameStr(*PG_GETARG_NAME(0));
 	const char *host = PG_ARGISNULL(1) ? NULL : TextDatumGetCString(PG_GETARG_DATUM(1));
 	const char *database = PG_ARGISNULL(2) ? NULL : NameStr(*PG_GETARG_NAME(2));
@@ -1826,6 +1884,18 @@ drop_data_node_database(const ForeignServer *server)
 Datum
 data_node_delete(PG_FUNCTION_ARGS)
 {
+#if PG16_GE
+	ereport(ERROR,
+			(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+			 errmsg("deleting data node is not supported"),
+			 errdetail("Multi-node is not supported anymore on PostgreSQL >= 16.")));
+#else
+	ereport(WARNING,
+			(errcode(ERRCODE_WARNING_DEPRECATED_FEATURE),
+			 errmsg("deleting data node is deprecated"),
+			 errdetail("Multi-node is deprecated and will be removed in future releases.")));
+#endif
+
 	const char *node_name = PG_ARGISNULL(0) ? NULL : PG_GETARG_CSTRING(0);
 	bool if_exists = PG_ARGISNULL(1) ? false : PG_GETARG_BOOL(1);
 	bool force = PG_ARGISNULL(2) ? false : PG_GETARG_BOOL(2);

tsl/src/dist_backup.c

@@ -65,6 +65,18 @@ create_restore_point_datum(TupleDesc tupdesc, const char *node_name, XLogRecPtr
 Datum
 create_distributed_restore_point(PG_FUNCTION_ARGS)
 {
+#if PG16_GE
+	ereport(ERROR,
+			(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+			 errmsg("creating distributed restore point is not supported"),
+			 errdetail("Multi-node is not supported anymore on PostgreSQL >= 16.")));
+#else
+	ereport(WARNING,
+			(errcode(ERRCODE_WARNING_DEPRECATED_FEATURE),
+			 errmsg("creating distributed restore point is deprecated"),
+			 errdetail("Multi-node is deprecated and will be removed in future releases.")));
+#endif
+
 	const char *name = TextDatumGetCString(PG_GETARG_DATUM(0));
 	DistCmdResult *result_cmd;
 	FuncCallContext *funcctx;

tsl/src/remote/dist_commands.c

@@ -523,6 +523,13 @@ ts_dist_cmd_close_prepared_command(PreparedDistCmd *command)
 Datum
 ts_dist_cmd_exec(PG_FUNCTION_ARGS)
 {
+#if PG16_GE
+	ereport(ERROR,
+			(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+			 errmsg("distributed command execution is not supported"),
+			 errdetail("Multi-node is not supported anymore on PostgreSQL >= 16.")));
+#endif
+
 	const char *query = PG_ARGISNULL(0) ? NULL : TextDatumGetCString(PG_GETARG_DATUM(0));
 	ArrayType *data_nodes = PG_ARGISNULL(1) ? NULL : PG_GETARG_ARRAYTYPE_P(1);
 	bool transactional = PG_ARGISNULL(2) ? true : PG_GETARG_BOOL(2);

tsl/test/expected/cagg_bgw_dist_ht.out

@@ -28,6 +28,9 @@ FROM (
   SELECT (add_data_node(name, host => 'localhost', DATABASE => name)).*
   FROM (VALUES (:'DATA_NODE_1'), (:'DATA_NODE_2'), (:'DATA_NODE_3')) v(name)
 ) a;
+WARNING:  adding data node is deprecated
+WARNING:  adding data node is deprecated
+WARNING:  adding data node is deprecated
        node_name       |       database        | node_created | database_created | extension_created 
 -----------------------+-----------------------+--------------+------------------+-------------------
  db_cagg_bgw_dist_ht_1 | db_cagg_bgw_dist_ht_1 | t            | t                | t
@@ -120,6 +123,7 @@ psql:include/cagg_bgw_common.sql:76: WARNING:  no privileges were granted for "p
 CREATE TABLE test_continuous_agg_table(time int, data int);
 \if :IS_DISTRIBUTED
 SELECT create_distributed_hypertable('test_continuous_agg_table', 'time', chunk_time_interval => 10, replication_factor => 2);
+psql:include/cagg_bgw_common.sql:80: WARNING:  distributed hypertable is deprecated
 psql:include/cagg_bgw_common.sql:80: NOTICE:  adding not-null constraint to column "time"
      create_distributed_hypertable      
 ----------------------------------------
@@ -610,6 +614,7 @@ SELECT ts_bgw_params_reset_time();
 CREATE TABLE test_continuous_agg_table_w_grant(time int, data int);
 \if :IS_DISTRIBUTED
 SELECT create_distributed_hypertable('test_continuous_agg_table_w_grant', 'time', chunk_time_interval => 10, replication_factor => 2);
+psql:include/cagg_bgw_common.sql:330: WARNING:  distributed hypertable is deprecated
 psql:include/cagg_bgw_common.sql:330: NOTICE:  adding not-null constraint to column "time"
          create_distributed_hypertable          
 ------------------------------------------------