/* ----------------
* ExecConditionalAssignProjectionInfo
*
* as ExecAssignProjectionInfo, but store NULL rather than building projection
* info if no projection is required
* ----------------
*/
void
ExecConditionalAssignProjectionInfo(PlanState *planstate, TupleDesc inputDesc,
Index varno)
{
if (tlist_matches_tupdesc(planstate,
planstate->plan->targetlist,
varno,
inputDesc))
{
planstate->ps_ProjInfo = NULL;
planstate->resultopsset = planstate->scanopsset;
planstate->resultopsfixed = planstate->scanopsfixed;
planstate->resultops = planstate->scanops;
}
else
{
if (!planstate->ps_ResultTupleSlot)
{
ExecInitResultSlot(planstate, &TTSOpsVirtual);
planstate->resultops = &TTSOpsVirtual;
planstate->resultopsfixed = true;
planstate->resultopsset = true;
}
ExecAssignProjectionInfo(planstate, inputDesc);
}
}
/*
* 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 node, because the planner will preferentially generate a matching
* tlist.
*
* ExecAssignScanType must have been called already.
*/
void
ExecAssignScanProjectionInfo(ScanState *node)
{
Scan *scan = (Scan *) node->ps.plan;
if (tlist_matches_tupdesc(&node->ps,
scan->plan.targetlist,
scan->scanrelid,
node->ss_ScanTupleSlot->tts_tupleDescriptor))
node->ps.ps_ProjInfo = NULL;
else
ExecAssignProjectionInfo(&node->ps,
node->ss_ScanTupleSlot->tts_tupleDescriptor);
}
/*
* 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 node, because the planner will preferentially generate a matching
* tlist.
*
* ExecAssignScanType must have been called already.
*/
void
ExecAssignScanProjectionInfo(ScanState *node)
{
Scan *scan = (Scan *) node->ps.plan;
Index varno;
/* Vars in an index-only scan's tlist should be INDEX_VAR */
if (IsA(scan, IndexOnlyScan))
varno = INDEX_VAR;
else
varno = scan->scanrelid;
if (tlist_matches_tupdesc(&node->ps,
scan->plan.targetlist,
varno,
node->ss_ScanTupleSlot->tts_tupleDescriptor))
node->ps.ps_ProjInfo = NULL;
else
ExecAssignProjectionInfo(&node->ps,
node->ss_ScanTupleSlot->tts_tupleDescriptor);
}
