Function GetExtTableEntryIfExists

src/backend/access/external/external.c:180–201

* Like GetExtTableEntry(Oid), but returns NULL instead of throwing * an error if no pg_foreign_table entry is found. */

 * an error if no pg_foreign_table entry is found.
 */
ExtTableEntry*
GetExtTableEntryIfExists(Oid relid)
{
	ForeignTable 	*ft;
	ExtTableEntry 	*extentry;

	/* do nothing if it's not an external table */
	if (!rel_is_external_table(relid))
		return NULL;

	ft = GetForeignTable(relid);

	/* options array is always populated, {} if no options set */
	if (ft->options == NULL)
		elog(ERROR, "could not find options for external protocol");

	extentry = GetExtFromForeignTableOptions(ft->options, relid);

	pfree(ft);

	return extentry;
}

ExtTableEntry *
GetExtFromForeignTableOptions(List *ftoptons, Oid relid)