add openGauss非内核级实现部分商业数据库兼容性功能

openGauss非内核级实现部分商业数据库兼容性功能

Signed-off-by: 刘文兴 <1349007648@qq.com>

OpenGaussCompatibleFunction/OpenGaussCompatibleFunction

@@ -0,0 +1,107 @@
+create schema open_descript;
+
+
+-- DBMS_DESCRIPT.DESCRIBE_PROCEDURE
+CREATE OR REPLACE FUNCTION open_descript.describe_procedure(in pname varchar)
+  RETURNS text AS $$
+DECLARE 
+    pdesc text;
+BEGIN
+	select prosrc into pdesc from pg_proc where proname = pname;
+	return pdesc;
+END;
+$$ LANGUAGE plpgsql;
+
+
+create schema open_debug;
+-- DBMS_DEBUG.SHOW_SOURCE
+CREATE OR REPLACE FUNCTION open_debug.show_source(
+	in oname varchar,in otype varchar)
+  RETURNS text AS $$
+DECLARE 
+    osource text;
+BEGIN
+	if (otype = 'index') then
+		select indexdef into osource from pg_indexes where indexname = oname; 
+	end if;
+	if (otype = 'function') then
+		select prosrc into osource from pg_proc where proname = oname;
+	else 
+		select definition into osource from pg_views where viewname = oname;
+	end if;
+	return osource;
+END;
+$$ LANGUAGE plpgsql;
+
+
+-- DBMS_DEBUG.PROBE_VERSION
+CREATE OR REPLACE FUNCTION open_debug.probe_version()
+  RETURNS text AS $$
+DECLARE 
+    pversion text;
+	mysql text;
+BEGIN
+	mysql := 'select version()';
+	execute mysql into pversion;
+	return pversion;
+END;
+$$ LANGUAGE plpgsql;
+
+
+-- DBMS_DEBUG.SET_TIMEOUT
+CREATE OR REPLACE FUNCTION open_debug.set_timeout(t integer)
+  RETURNS boolean AS $$
+DECLARE 
+    stimeout text;
+	mysql text;
+BEGIN
+	-- 只针对当前session
+	mysql :='set statement_timeout = ' || t;
+	execute mysql;
+	return stimeout;
+END;
+$$ LANGUAGE plpgsql;
+
+
+-- DBMS_SESSION.IS_SESSION_ALIVE
+CREATE OR REPLACE FUNCTION open_session.is_active_session(in pno int)
+  RETURNS text AS $$
+DECLARE 
+    ac text;
+BEGIN
+	select state into ac from pg_stat_activity where pid = pno;
+	return ac;
+END;
+$$ LANGUAGE plpgsql;
+
+-- DBMS_SESSION.SET_ROLE
+CREATE OR REPLACE FUNCTION open_session.set_role(in username text,in rolename text)
+  RETURNS boolean AS $$
+DECLARE 
+    passed boolean;
+	mysql text;
+BEGIN
+	mysql :='alter user '|| username ||' '||rolename ||'';
+	execute mysql;
+	return passed;
+END;
+$$ LANGUAGE plpgsql;
+
+
+-- DBMS_SESSION.UNIQUE_SESSION_ID
+CREATE OR REPLACE FUNCTION open_session.unique_session_id()
+  RETURNS text AS $$
+DECLARE 
+    passed text;
+	mysql text;
+BEGIN
+	mysql :='select distinct pid from pg_stat_activity';
+	execute mysql into passed;
+	return passed;
+END;
+$$ LANGUAGE plpgsql;
+
+
+
+
+