Function ExecAssignScanProjectionInfo

src/backend/executor/execScan.c:286–293

* ExecAssignScanProjectionInfo * Set up projection info for a scan node, if necessary. * * We can avoid a projection step if the requested tlist exactly matches * the underlying tuple type. If so, we just set ps_ProjInfo to NULL. * Note that this case occurs not only for simple "SELECT * FROM ...", but * also in most cases where there are joins or other processing nodes above * the scan n

 * The scan slot's descriptor must have been set already.
 */
void
ExecAssignScanProjectionInfo(ScanState *node)
{
	Scan	   *scan = (Scan *) node->ps.plan;
	TupleDesc	tupdesc = node->ss_ScanTupleSlot->tts_tupleDescriptor;

	ExecConditionalAssignProjectionInfo(&node->ps, tupdesc, scan->scanrelid);
}

/*
 * ExecAssignScanProjectionInfoWithVarno