Function RelationParseRelOptions

src/backend/utils/cache/relcache.c:479–533

* RelationParseRelOptions * Convert pg_class.reloptions into pre-parsed rd_options * * tuple is the real pg_class tuple (not rd_rel!) for relation * * Note: rd_rel and (if an index) rd_indam must be valid already */

 * Note: rd_rel and (if an index) rd_indam must be valid already
 */
static void
RelationParseRelOptions(Relation relation, HeapTuple tuple)
{
	bytea	   *options;
	reloption_function amoptsfn;

	relation->rd_options = NULL;

	/*
	 * Look up any AM-specific parse function; fall out if relkind should not
	 * have options.
	 */
	switch (relation->rd_rel->relkind)
	{
		case RELKIND_RELATION:
		case RELKIND_TOASTVALUE:
		case RELKIND_MATVIEW:
		case RELKIND_AOSEGMENTS:
		case RELKIND_AOBLOCKDIR:
		case RELKIND_AOVISIMAP:
			amoptsfn = relation->rd_tableam->amoptions;
			break;
		case RELKIND_VIEW:
		case RELKIND_PARTITIONED_TABLE:
			amoptsfn = NULL;
			break;
		case RELKIND_INDEX:
		case RELKIND_PARTITIONED_INDEX:
			amoptsfn = relation->rd_indam->amoptions;
			break;
		default:
			return;
	}

	/*
	 * Fetch reloptions from tuple; have to use a hardwired descriptor because
	 * we might not have any other for pg_class yet (consider executing this
	 * code for pg_class itself)
	 */
	options = extractRelOptions(tuple, GetPgClassDescriptor(), amoptsfn);

	/*
	 * Copy parsed data into CacheMemoryContext.  To guard against the
	 * possibility of leaks in the reloptions code, we want to do the actual
	 * parsing in the caller's memory context and copy the results into
	 * CacheMemoryContext after the fact.
	 */
	if (options)
	{
		relation->rd_options = MemoryContextAlloc(CacheMemoryContext,
												  VARSIZE(options));
		memcpy(relation->rd_options, options, VARSIZE(options));
		pfree(options);
	}
}

/*
 *		RelationBuildTupleDesc