add T_GroupingFunc to pgxc_shippability_walker

Planning grouping sets queries with grouping() function failed with

    ERROR:  XX000: unrecognized node type: 307
    LOCATION:  pgxc_shippability_walker, pgxcship.c:1199
    STATEMENT:  select grouping(a, b), count(*) from t1
                group by grouping sets ((a), (b));

We simply inspect arguments of the grouping() function, although
that probably is not necessary - it can only reference grouping
expressions, which are checked as part of other nodes.

1 files changed, 10 insertions, 0 deletions

diff --git a/src/backend/optimizer/util/pgxcship.c b/src/backend/optimizer/util/pgxcship.c
index a8f3d94d44..bcee7e8d00 100644
--- a/src/backend/optimizer/util/pgxcship.c
+++ b/src/backend/optimizer/util/pgxcship.c
@@ -1194,6 +1194,16 @@ pgxc_shippability_walker(Node *node, Shippability_context *sc_context)
 		}
 		break;
 
+		case T_GroupingFunc:
+			/*
+			 * Let expression tree walker inspect the arguments. Not sure if
+			 * that's necessary, as those are just references to grouping
+			 * expressions of the query (and thus likely examined as part
+			 * of another node).
+			 */
+			return expression_tree_walker(node, pgxc_shippability_walker,
+										  sc_context);
+
 		default:
 			elog(ERROR, "unrecognized node type: %d",
 				 (int) nodeTag(node));