Make gp_cte_sharing globally configurable

During CTE feature development, we discovered that the gp_cte_sharing
GUC
cannot be configured at the server level, which complicates testing of
CTE sharing functionality.

This GUC was introduced ten years ago, and there is no apparent reason
why it should not be configurable globally. This change enables more
flexible testing and deployment configurations.

Authored-by: Zhang Mingli [email protected]

Author: avamingli

src/backend/utils/misc/guc_gp.c

@@ -1796,8 +1796,7 @@ struct config_bool ConfigureNamesBool_gp[] =
 	{
 		{"gp_cte_sharing", PGC_USERSET, QUERY_TUNING_METHOD,
 			gettext_noop("This guc enables sharing of plan fragments for common table expressions."),
-			NULL,
-			GUC_NO_SHOW_ALL | GUC_NOT_IN_SAMPLE
+			NULL
 		},
 		&gp_cte_sharing,
 		false,