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Allow tupleslots to have a fixed tupledesc, use in executor nodes.

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The reason for doing so is that it will allow expression evaluation to
optimize based on the underlying tupledesc. In particular it will
allow to JIT tuple deforming together with the expression itself.

For that expression initialization needs to be moved after the
relevant slots are initialized - mostly unproblematic, except in the
case of nodeWorktablescan.c.

After doing so there's no need for ExecAssignResultType() and
ExecAssignResultTypeFromTL() anymore, as all former callers have been
converted to create a slot with a fixed descriptor.

When creating a slot with a fixed descriptor, tts_values/isnull can be
allocated together with the main slot, reducing allocation overhead
and increasing cache density a bit.

Author: Andres Freund
Discussion: https://postgr.es/m/20171206093717.vqdxe5icqttpxs3p@alap3.anarazel.de
This commit is contained in:
Andres Freund
2018-02-16 21:17:38 -08:00
parent bf6c614a2f
commit ad7dbee368
52 changed files with 579 additions and 791 deletions
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62
src/backend/executor/execUtils.c
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@ -22,7 +22,6 @@
* ReScanExprContext
*
* ExecAssignExprContext Common code for plan node init routines.
* ExecAssignResultType
* etc
*
* ExecOpenScanRelation Common code for scan node init routines.
@ -428,47 +427,6 @@ ExecAssignExprContext(EState *estate, PlanState *planstate)
planstate->ps_ExprContext = CreateExprContext(estate);
}
/* ----------------
* ExecAssignResultType
* ----------------
*/
void
ExecAssignResultType(PlanState *planstate, TupleDesc tupDesc)
{
TupleTableSlot *slot = planstate->ps_ResultTupleSlot;
ExecSetSlotDescriptor(slot, tupDesc);
}
/* ----------------
* ExecAssignResultTypeFromTL
* ----------------
*/
void
ExecAssignResultTypeFromTL(PlanState *planstate)
{
bool hasoid;
TupleDesc tupDesc;
if (ExecContextForcesOids(planstate, &hasoid))
{
/* context forces OID choice; hasoid is now set correctly */
}
else
{
/* given free choice, don't leave space for OIDs in result tuples */
hasoid = false;
}
/*
* ExecTypeFromTL needs the parse-time representation of the tlist, not a
* list of ExprStates. This is good because some plan nodes don't bother
* to set up planstate->targetlist ...
*/
tupDesc = ExecTypeFromTL(planstate->plan->targetlist, hasoid);
ExecAssignResultType(planstate, tupDesc);
}
/* ----------------
* ExecGetResultType
* ----------------
@ -609,13 +567,9 @@ ExecFreeExprContext(PlanState *planstate)
planstate->ps_ExprContext = NULL;
}
/* ----------------------------------------------------------------
* the following scan type support functions are for
* those nodes which are stubborn and return tuples in
* their Scan tuple slot instead of their Result tuple
* slot.. luck fur us, these nodes do not do projections
* so we don't have to worry about getting the ProjectionInfo
* right for them... -cim 6/3/91
* Scan node support
* ----------------------------------------------------------------
*/
@ -632,11 +586,11 @@ ExecAssignScanType(ScanState *scanstate, TupleDesc tupDesc)
}
/* ----------------
* ExecAssignScanTypeFromOuterPlan
* ExecCreateSlotFromOuterPlan
* ----------------
*/
void
ExecAssignScanTypeFromOuterPlan(ScanState *scanstate)
ExecCreateScanSlotFromOuterPlan(EState *estate, ScanState *scanstate)
{
PlanState *outerPlan;
TupleDesc tupDesc;
@ -644,15 +598,9 @@ ExecAssignScanTypeFromOuterPlan(ScanState *scanstate)
outerPlan = outerPlanState(scanstate);
tupDesc = ExecGetResultType(outerPlan);
ExecAssignScanType(scanstate, tupDesc);
ExecInitScanTupleSlot(estate, scanstate, tupDesc);
}
/* ----------------------------------------------------------------
* Scan node support
* ----------------------------------------------------------------
*/
/* ----------------------------------------------------------------
* ExecRelationIsTargetRelation
*