Fix command redirection to shardlord

Author: knizhnik

pg_shardman--1.0.sql

@@ -662,12 +662,10 @@ $$ LANGUAGE sql;
 
 -- Execute command at shardlord
 CREATE FUNCTION redirect_to_shardlord(cmd text) RETURNS bool AS $$
-DECLARE
-	am_shardlord bool;
 BEGIN
-	SELECT setting::bool INTO am_shardlord FROM pg_settings WHERE name = 'shardman.shardlord';
-	IF NOT am_shardlord THEN
-		PERFORM shardman.broadcast(format('0:SELECT %s;', cmd));
+	IF NOT shardman.is_shardlord() THEN
+	    RAISE NOTICE 'Redirect command "%" to shardlord',cmd;
+		PERFORM shardman.broadcast(format('0:SELECT shardman.%s;', cmd));
 		RETURN true;
 	ELSE
 		RETURN false;
@@ -772,10 +770,14 @@ CREATE FUNCTION pq_conninfo_parse(IN conninfo text, OUT keys text[], OUT vals te
 CREATE FUNCTION shardlord_connection_string()
 	RETURNS text AS 'pg_shardman' LANGUAGE C STRICT;
 
--- Check from configuration parameters is synchronous replication mode was enabled
+-- Check from configuration parameters if synchronous replication mode was enabled
 CREATE FUNCTION synchronous_replication()
 	RETURNS bool AS 'pg_shardman' LANGUAGE C STRICT;
 
+-- Check from configuration parameters if node plays role of shardlord
+CREATE FUNCTION is_shardlord()
+	RETURNS bool AS 'pg_shardman' LANGUAGE C STRICT;
+
 -- Wait completion of partition copy using LR
 CREATE FUNCTION wait_copy_completion(src_node_id int, part_name text) RETURNS void AS $$
 DECLARE

pg_shardman.c

@@ -25,12 +25,13 @@ PG_MODULE_MAGIC;
 
 PG_FUNCTION_INFO_V1(shardlord_connection_string);
 PG_FUNCTION_INFO_V1(synchronous_replication);
+PG_FUNCTION_INFO_V1(is_shardlord);
 PG_FUNCTION_INFO_V1(broadcast);
 PG_FUNCTION_INFO_V1(reconstruct_table_attrs);
 PG_FUNCTION_INFO_V1(pq_conninfo_parse);
 
 /* GUC variables */
-static bool is_shardlord;
+static bool is_lord;
 static bool sync_replication;
 static char *shardlord_connstring;
 
@@ -56,7 +57,7 @@ _PG_init()
 		"shardman.shardlord",
 		"This node is the shardlord?",
 		NULL,
-		&is_shardlord,
+		&is_lord,
 		false,
 		PGC_SUSET,
 		0,
@@ -86,6 +87,12 @@ synchronous_replication(PG_FUNCTION_ARGS)
 	PG_RETURN_BOOL(sync_replication);
 }
 
+Datum
+is_shardlord(PG_FUNCTION_ARGS)
+{
+	PG_RETURN_BOOL(is_lord);
+}
+
 static bool
 wait_command_completion(PGconn* conn)
 {