Function GetRTEByRangeTablePosn

src/backend/parser/parse_relation.c:525–537

* Given an RT index and nesting depth, find the corresponding RTE. * (Note that the RTE need not be in the query's namespace.) */

 * (Note that the RTE need not be in the query's namespace.)
 */
RangeTblEntry *
GetRTEByRangeTablePosn(ParseState *pstate,
					   int varno,
					   int sublevels_up)
{
	while (sublevels_up-- > 0)
	{
		pstate = pstate->parentParseState;
		Assert(pstate != NULL);
	}
	Assert(varno > 0 && varno <= list_length(pstate->p_rtable));
	return rt_fetch(varno, pstate->p_rtable);
}

/*
 * Fetch the CTE for a CTE-reference RTE.