Enable ORCA if lib is loaded

gpcontrib/gp_orca/gporca.c

@@ -10,6 +10,8 @@
 #include "utils/memutils.h"
 #include "utils/guc.h"
 
+extern bool optimizer;
+
 extern void InitGPOPT();
 extern void TerminateGPOPT();
 
@@ -119,6 +121,9 @@ _PG_init(void)
 
 		prev_planner = planner_hook;
 		planner_hook = gp_orca_planner;
+
+		/* enable orca here */
+		optimizer = true;
 	}
 }
 
@@ -128,6 +133,9 @@ _PG_fini(void)
 	elog(LOG, "[GP_ORCA] _PG_fini");
 	if (Gp_role == GP_ROLE_DISPATCH)
 	{
+		/* disable orca here */
+		optimizer = false;
+
 		planner_hook = prev_planner;
 
 		TerminateGPOPT();

src/backend/optimizer/plan/planner.c

@@ -354,9 +354,6 @@ standard_planner(Query *parse, int cursorOptions, ParamListInfo boundParams)
 	instr_time		starttime;
 	instr_time		endtime;
 
-	if (optimizer)
-		elog(ERROR, "Add gp_orca to shared_preload_libraries");
-
 	/*
 	 * Fall back to using the PostgreSQL planner in case Orca didn't run (in
 	 * utility mode or on a segment) or if it didn't produce a plan.