Function table_beginscan_es

src/include/access/tableam.h:1035–1072

* GPDB: Like table_beginscan(), but first attempt to create a * scan key array from the targetList and the quals if the corresponding method * is implemented. This is an optimization needed for AOCO relations. * Otherwise, it is equivalent as passing the last two arguments as, 0, NULL. * Like table_beginscan_parallel, it will be parallel mode if parallel_scan is not NULL. */

 * Like table_beginscan_parallel, it will be parallel mode if parallel_scan is not NULL.
 */
static inline TableScanDesc
table_beginscan_es(Relation relation, Snapshot snapshot,
				   int nkeys, struct ScanKeyData *key,
				   ParallelTableScanDesc parallel_scan,
				   struct PlanState *ps)
{
	bool isParallel = parallel_scan != NULL;
	uint32		flags = SO_TYPE_SEQSCAN |
	SO_ALLOW_STRAT | SO_ALLOW_SYNC | SO_ALLOW_PAGEMODE;

	/* reset snapshot if in parallel mode */
	if (isParallel)
	{
		Assert(RelationGetRelid(relation) == parallel_scan->phs_relid);
		if (!parallel_scan->phs_snapshot_any) {
			/* Snapshot was serialized -- restore it */
			snapshot = RestoreSnapshot((char *) parallel_scan +
									   parallel_scan->phs_snapshot_off);
			RegisterSnapshot(snapshot);
			flags |= SO_TEMP_SNAPSHOT;
		}
		else
		{
			/* SnapshotAny passed by caller (not serialized) */
			snapshot = SnapshotAny;
		}
	}

	if (relation->rd_tableam->scan_begin_extractcolumns)
		return relation->rd_tableam->scan_begin_extractcolumns(relation, snapshot,
															   nkeys, key,
															   parallel_scan,
															   ps, flags);

	return relation->rd_tableam->scan_begin(relation, snapshot,
									   nkeys, key,
									   parallel_scan, flags);
}

/*
 * Like table_beginscan(), but for scanning catalog. It'll automatically use a