Function ATExecGenericOptions

src/backend/commands/tablecmds.c:19867–19940

* ALTER FOREIGN TABLE OPTIONS (...) */

 * ALTER FOREIGN TABLE <name> OPTIONS (...)
 */
static void
ATExecGenericOptions(Relation rel, List *options)
{
	Relation	ftrel;
	ForeignServer *server;
	ForeignDataWrapper *fdw;
	HeapTuple	tuple;
	bool		isnull;
	Datum		repl_val[Natts_pg_foreign_table];
	bool		repl_null[Natts_pg_foreign_table];
	bool		repl_repl[Natts_pg_foreign_table];
	Datum		datum;
	Form_pg_foreign_table tableform;

	if (options == NIL)
		return;

	ftrel = table_open(ForeignTableRelationId, RowExclusiveLock);

	tuple = SearchSysCacheCopy1(FOREIGNTABLEREL, rel->rd_id);
	if (!HeapTupleIsValid(tuple))
		ereport(ERROR,
				(errcode(ERRCODE_UNDEFINED_OBJECT),
				 errmsg("foreign table \"%s\" does not exist",
						RelationGetRelationName(rel))));
	tableform = (Form_pg_foreign_table) GETSTRUCT(tuple);
	server = GetForeignServer(tableform->ftserver);
	fdw = GetForeignDataWrapper(server->fdwid);

	memset(repl_val, 0, sizeof(repl_val));
	memset(repl_null, false, sizeof(repl_null));
	memset(repl_repl, false, sizeof(repl_repl));

	/* Extract the current options */
	datum = SysCacheGetAttr(FOREIGNTABLEREL,
							tuple,
							Anum_pg_foreign_table_ftoptions,
							&isnull);
	if (isnull)
		datum = PointerGetDatum(NULL);

	/* Transform the options */
	datum = transformGenericOptions(ForeignTableRelationId,
									datum,
									options,
									fdw->fdwvalidator);

	if (PointerIsValid(DatumGetPointer(datum)))
		repl_val[Anum_pg_foreign_table_ftoptions - 1] = datum;
	else
		repl_null[Anum_pg_foreign_table_ftoptions - 1] = true;

	repl_repl[Anum_pg_foreign_table_ftoptions - 1] = true;

	/* Everything looks good - update the tuple */

	tuple = heap_modify_tuple(tuple, RelationGetDescr(ftrel),
							  repl_val, repl_null, repl_repl);