Add result_types column to pg_prepared_statements view

Containing the types of the columns returned by the prepared
statement.

Prompted by question from IRC user mlvzk.

Author: Dagfinn Ilmari Mannsåker <[email protected]>
Discussion: https://www.postgresql.org/message-id/flat/[email protected]

1 files changed, 14 insertions, 5 deletions

diff --git a/src/backend/commands/prepare.c b/src/backend/commands/prepare.c
index 633c9a40bbc..d1deb97fffb 100644
--- a/src/backend/commands/prepare.c
+++ b/src/backend/commands/prepare.c
@@ -683,8 +683,16 @@ pg_prepared_statement(PG_FUNCTION_ARGS)
 		hash_seq_init(&hash_seq, prepared_queries);
 		while ((prep_stmt = hash_seq_search(&hash_seq)) != NULL)
 		{
-			Datum		values[7];
-			bool		nulls[7];
+			TupleDesc	result_desc;
+			Oid		   *result_types;
+			Datum		values[8];
+			bool		nulls[8];
+
+			result_desc = prep_stmt->plansource->resultDesc;
+			result_types = (Oid *) palloc(result_desc->natts * sizeof(Oid));
+
+			for (int i = 0; i < result_desc->natts; i++)
+				result_types[i] = result_desc->attrs[i].atttypid;
 
 			MemSet(nulls, 0, sizeof(nulls));
 
@@ -693,9 +701,10 @@ pg_prepared_statement(PG_FUNCTION_ARGS)
 			values[2] = TimestampTzGetDatum(prep_stmt->prepare_time);
 			values[3] = build_regtype_array(prep_stmt->plansource->param_types,
 											prep_stmt->plansource->num_params);
-			values[4] = BoolGetDatum(prep_stmt->from_sql);
-			values[5] = Int64GetDatumFast(prep_stmt->plansource->num_generic_plans);
-			values[6] = Int64GetDatumFast(prep_stmt->plansource->num_custom_plans);
+			values[4] = build_regtype_array(result_types, result_desc->natts);
+			values[5] = BoolGetDatum(prep_stmt->from_sql);
+			values[6] = Int64GetDatumFast(prep_stmt->plansource->num_generic_plans);
+			values[7] = Int64GetDatumFast(prep_stmt->plansource->num_custom_plans);
 
 			tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc,
 								 values, nulls);