* subplans, which are re-evaluated every time their result is required.
*
*
- * Portions Copyright (c) 1996-2017, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1996-2019, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
#include "executor/executor.h"
#include "executor/nodeSubplan.h"
#include "nodes/makefuncs.h"
-#include "optimizer/clauses.h"
+#include "nodes/nodeFuncs.h"
+#include "miscadmin.h"
#include "utils/array.h"
#include "utils/lsyscache.h"
#include "utils/memutils.h"
-static Datum ExecSubPlan(SubPlanState *node,
- ExprContext *econtext,
- bool *isNull);
-static Datum ExecAlternativeSubPlan(AlternativeSubPlanState *node,
- ExprContext *econtext,
- bool *isNull);
static Datum ExecHashSubPlan(SubPlanState *node,
ExprContext *econtext,
bool *isNull);
* This is the main entry point for execution of a regular SubPlan.
* ----------------------------------------------------------------
*/
-static Datum
+Datum
ExecSubPlan(SubPlanState *node,
ExprContext *econtext,
bool *isNull)
{
- SubPlan *subplan = (SubPlan *) node->xprstate.expr;
+ SubPlan *subplan = node->subplan;
+ EState *estate = node->planstate->state;
+ ScanDirection dir = estate->es_direction;
+ Datum retval;
+
+ CHECK_FOR_INTERRUPTS();
/* Set non-null as default */
*isNull = false;
if (subplan->setParam != NIL && subplan->subLinkType != MULTIEXPR_SUBLINK)
elog(ERROR, "cannot set parent params from subquery");
+ /* Force forward-scan mode for evaluation */
+ estate->es_direction = ForwardScanDirection;
+
/* Select appropriate evaluation strategy */
if (subplan->useHashTable)
- return ExecHashSubPlan(node, econtext, isNull);
+ retval = ExecHashSubPlan(node, econtext, isNull);
else
- return ExecScanSubPlan(node, econtext, isNull);
+ retval = ExecScanSubPlan(node, econtext, isNull);
+
+ /* restore scan direction */
+ estate->es_direction = dir;
+
+ return retval;
}
/*
ExprContext *econtext,
bool *isNull)
{
- SubPlan *subplan = (SubPlan *) node->xprstate.expr;
+ SubPlan *subplan = node->subplan;
PlanState *planstate = node->planstate;
TupleTableSlot *slot;
if (node->havehashrows &&
FindTupleHashEntry(node->hashtable,
slot,
- node->cur_eq_funcs,
+ node->cur_eq_comp,
node->lhs_hash_funcs) != NULL)
{
ExecClearTuple(slot);
ExprContext *econtext,
bool *isNull)
{
- SubPlan *subplan = (SubPlan *) node->xprstate.expr;
+ SubPlan *subplan = node->subplan;
PlanState *planstate = node->planstate;
SubLinkType subLinkType = subplan->subLinkType;
MemoryContext oldcontext;
TupleTableSlot *slot;
Datum result;
- bool found = false; /* TRUE if got at least one subplan tuple */
+ bool found = false; /* true if got at least one subplan tuple */
ListCell *pvar;
ListCell *l;
ArrayBuildStateAny *astate = NULL;
*/
if (node->curTuple)
heap_freetuple(node->curTuple);
- node->curTuple = ExecCopySlotTuple(slot);
+ node->curTuple = ExecCopySlotHeapTuple(slot);
result = heap_getattr(node->curTuple, 1, tdesc, isNull);
/* keep scanning subplan to make sure there's only one tuple */
found = true;
/* stash away current value */
- Assert(subplan->firstColType == tdesc->attrs[0]->atttypid);
+ Assert(subplan->firstColType == TupleDescAttr(tdesc, 0)->atttypid);
dvalue = slot_getattr(slot, 1, &disnull);
astate = accumArrayResultAny(astate, dvalue, disnull,
subplan->firstColType, oldcontext);
static void
buildSubPlanHash(SubPlanState *node, ExprContext *econtext)
{
- SubPlan *subplan = (SubPlan *) node->xprstate.expr;
+ SubPlan *subplan = node->subplan;
PlanState *planstate = node->planstate;
int ncols = list_length(subplan->paramIds);
ExprContext *innerecontext = node->innerecontext;
if (nbuckets < 1)
nbuckets = 1;
- node->hashtable = BuildTupleHashTable(ncols,
+ node->hashtable = BuildTupleHashTable(node->parent,
+ node->descRight,
+ ncols,
node->keyColIdx,
- node->tab_eq_funcs,
+ node->tab_eq_funcoids,
node->tab_hash_funcs,
nbuckets,
0,
if (nbuckets < 1)
nbuckets = 1;
}
- node->hashnulls = BuildTupleHashTable(ncols,
+ node->hashnulls = BuildTupleHashTable(node->parent,
+ node->descRight,
+ ncols,
node->keyColIdx,
- node->tab_eq_funcs,
+ node->tab_eq_funcoids,
node->tab_hash_funcs,
nbuckets,
0,
* potential for a double free attempt. (XXX possibly no longer needed,
* but can't hurt.)
*/
- ExecClearTuple(node->projRight->pi_slot);
+ ExecClearTuple(node->projRight->pi_state.resultslot);
MemoryContextSwitchTo(oldcontext);
}
+/*
+ * execTuplesUnequal
+ * Return true if two tuples are definitely unequal in the indicated
+ * fields.
+ *
+ * Nulls are neither equal nor unequal to anything else. A true result
+ * is obtained only if there are non-null fields that compare not-equal.
+ *
+ * slot1, slot2: the tuples to compare (must have same columns!)
+ * numCols: the number of attributes to be examined
+ * matchColIdx: array of attribute column numbers
+ * eqFunctions: array of fmgr lookup info for the equality functions to use
+ * evalContext: short-term memory context for executing the functions
+ */
+static bool
+execTuplesUnequal(TupleTableSlot *slot1,
+ TupleTableSlot *slot2,
+ int numCols,
+ AttrNumber *matchColIdx,
+ FmgrInfo *eqfunctions,
+ MemoryContext evalContext)
+{
+ MemoryContext oldContext;
+ bool result;
+ int i;
+
+ /* Reset and switch into the temp context. */
+ MemoryContextReset(evalContext);
+ oldContext = MemoryContextSwitchTo(evalContext);
+
+ /*
+ * We cannot report a match without checking all the fields, but we can
+ * report a non-match as soon as we find unequal fields. So, start
+ * comparing at the last field (least significant sort key). That's the
+ * most likely to be different if we are dealing with sorted input.
+ */
+ result = false;
+
+ for (i = numCols; --i >= 0;)
+ {
+ AttrNumber att = matchColIdx[i];
+ Datum attr1,
+ attr2;
+ bool isNull1,
+ isNull2;
+
+ attr1 = slot_getattr(slot1, att, &isNull1);
+
+ if (isNull1)
+ continue; /* can't prove anything here */
+
+ attr2 = slot_getattr(slot2, att, &isNull2);
+
+ if (isNull2)
+ continue; /* can't prove anything here */
+
+ /* Apply the type-specific equality function */
+
+ if (!DatumGetBool(FunctionCall2(&eqfunctions[i],
+ attr1, attr2)))
+ {
+ result = true; /* they are unequal */
+ break;
+ }
+ }
+
+ MemoryContextSwitchTo(oldContext);
+
+ return result;
+}
+
/*
* findPartialMatch: does the hashtable contain an entry that is not
* provably distinct from the tuple?
InitTupleHashIterator(hashtable, &hashiter);
while ((entry = ScanTupleHashTable(hashtable, &hashiter)) != NULL)
{
+ CHECK_FOR_INTERRUPTS();
+
ExecStoreMinimalTuple(entry->firstTuple, hashtable->tableslot, false);
if (!execTuplesUnequal(slot, hashtable->tableslot,
numCols, keyColIdx,
SubPlanState *sstate = makeNode(SubPlanState);
EState *estate = parent->state;
- sstate->xprstate.evalfunc = (ExprStateEvalFunc) ExecSubPlan;
- sstate->xprstate.expr = (Expr *) subplan;
+ sstate->subplan = subplan;
/* Link the SubPlanState to already-initialized subplan */
sstate->planstate = (PlanState *) list_nth(estate->es_subplanstates,
/* Initialize subexpressions */
sstate->testexpr = ExecInitExpr((Expr *) subplan->testexpr, parent);
- sstate->args = (List *) ExecInitExpr((Expr *) subplan->args, parent);
+ sstate->args = ExecInitExprList(subplan->args, parent);
/*
* initialize my state
sstate->hashtempcxt = NULL;
sstate->innerecontext = NULL;
sstate->keyColIdx = NULL;
+ sstate->tab_eq_funcoids = NULL;
sstate->tab_hash_funcs = NULL;
sstate->tab_eq_funcs = NULL;
sstate->lhs_hash_funcs = NULL;
{
int ncols,
i;
- TupleDesc tupDesc;
+ TupleDesc tupDescLeft;
+ TupleDesc tupDescRight;
TupleTableSlot *slot;
List *oplist,
*lefttlist,
- *righttlist,
- *leftptlist,
- *rightptlist;
+ *righttlist;
ListCell *l;
/* We need a memory context to hold the hash table(s) */
* use the sub-select's output tuples directly, but that is not the
* case if we had to insert any run-time coercions of the sub-select's
* output datatypes; anyway this avoids storing any resjunk columns
- * that might be in the sub-select's output.) Run through the
+ * that might be in the sub-select's output.) Run through the
* combining expressions to build tlists for the lefthand and
- * righthand sides. We need both the ExprState list (for ExecProject)
- * and the underlying parse Exprs (for ExecTypeFromTL).
+ * righthand sides.
*
* We also extract the combining operators themselves to initialize
* the equality and hashing functions for the hash tables.
*/
- if (IsA(sstate->testexpr->expr, OpExpr))
+ if (IsA(subplan->testexpr, OpExpr))
{
/* single combining operator */
- oplist = list_make1(sstate->testexpr);
+ oplist = list_make1(subplan->testexpr);
}
- else if (and_clause((Node *) sstate->testexpr->expr))
+ else if (is_andclause(subplan->testexpr))
{
/* multiple combining operators */
- Assert(IsA(sstate->testexpr, BoolExprState));
- oplist = ((BoolExprState *) sstate->testexpr)->args;
+ oplist = castNode(BoolExpr, subplan->testexpr)->args;
}
else
{
/* shouldn't see anything else in a hashable subplan */
elog(ERROR, "unrecognized testexpr type: %d",
- (int) nodeTag(sstate->testexpr->expr));
+ (int) nodeTag(subplan->testexpr));
oplist = NIL; /* keep compiler quiet */
}
Assert(list_length(oplist) == ncols);
lefttlist = righttlist = NIL;
- leftptlist = rightptlist = NIL;
+ sstate->tab_eq_funcoids = (Oid *) palloc(ncols * sizeof(Oid));
sstate->tab_hash_funcs = (FmgrInfo *) palloc(ncols * sizeof(FmgrInfo));
sstate->tab_eq_funcs = (FmgrInfo *) palloc(ncols * sizeof(FmgrInfo));
sstate->lhs_hash_funcs = (FmgrInfo *) palloc(ncols * sizeof(FmgrInfo));
i = 1;
foreach(l, oplist)
{
- FuncExprState *fstate = (FuncExprState *) lfirst(l);
- OpExpr *opexpr = (OpExpr *) fstate->xprstate.expr;
- ExprState *exstate;
+ OpExpr *opexpr = lfirst_node(OpExpr, l);
Expr *expr;
TargetEntry *tle;
- GenericExprState *tlestate;
Oid rhs_eq_oper;
Oid left_hashfn;
Oid right_hashfn;
- Assert(IsA(fstate, FuncExprState));
- Assert(IsA(opexpr, OpExpr));
- Assert(list_length(fstate->args) == 2);
+ Assert(list_length(opexpr->args) == 2);
/* Process lefthand argument */
- exstate = (ExprState *) linitial(fstate->args);
- expr = exstate->expr;
+ expr = (Expr *) linitial(opexpr->args);
tle = makeTargetEntry(expr,
i,
NULL,
false);
- tlestate = makeNode(GenericExprState);
- tlestate->xprstate.expr = (Expr *) tle;
- tlestate->xprstate.evalfunc = NULL;
- tlestate->arg = exstate;
- lefttlist = lappend(lefttlist, tlestate);
- leftptlist = lappend(leftptlist, tle);
+ lefttlist = lappend(lefttlist, tle);
/* Process righthand argument */
- exstate = (ExprState *) lsecond(fstate->args);
- expr = exstate->expr;
+ expr = (Expr *) lsecond(opexpr->args);
tle = makeTargetEntry(expr,
i,
NULL,
false);
- tlestate = makeNode(GenericExprState);
- tlestate->xprstate.expr = (Expr *) tle;
- tlestate->xprstate.evalfunc = NULL;
- tlestate->arg = exstate;
- righttlist = lappend(righttlist, tlestate);
- rightptlist = lappend(rightptlist, tle);
+ righttlist = lappend(righttlist, tle);
/* Lookup the equality function (potentially cross-type) */
+ sstate->tab_eq_funcoids[i - 1] = opexpr->opfuncid;
fmgr_info(opexpr->opfuncid, &sstate->cur_eq_funcs[i - 1]);
fmgr_info_set_expr((Node *) opexpr, &sstate->cur_eq_funcs[i - 1]);
* (hack alert!). The righthand expressions will be evaluated in our
* own innerecontext.
*/
- tupDesc = ExecTypeFromTL(leftptlist, false);
- slot = ExecInitExtraTupleSlot(estate);
- ExecSetSlotDescriptor(slot, tupDesc);
+ tupDescLeft = ExecTypeFromTL(lefttlist);
+ slot = ExecInitExtraTupleSlot(estate, tupDescLeft, &TTSOpsVirtual);
sstate->projLeft = ExecBuildProjectionInfo(lefttlist,
NULL,
slot,
+ parent,
NULL);
- tupDesc = ExecTypeFromTL(rightptlist, false);
- slot = ExecInitExtraTupleSlot(estate);
- ExecSetSlotDescriptor(slot, tupDesc);
+ sstate->descRight = tupDescRight = ExecTypeFromTL(righttlist);
+ slot = ExecInitExtraTupleSlot(estate, tupDescRight, &TTSOpsVirtual);
sstate->projRight = ExecBuildProjectionInfo(righttlist,
sstate->innerecontext,
slot,
+ sstate->planstate,
NULL);
+
+ /*
+ * Create comparator for lookups of rows in the table (potentially
+ * across-type comparison).
+ */
+ sstate->cur_eq_comp = ExecBuildGroupingEqual(tupDescLeft, tupDescRight,
+ &TTSOpsVirtual, &TTSOpsMinimalTuple,
+ ncols,
+ sstate->keyColIdx,
+ sstate->tab_eq_funcoids,
+ parent);
+
}
return sstate;
* of initplans: we don't run the subplan until/unless we need its output.
* Note that this routine MUST clear the execPlan fields of the plan's
* output parameters after evaluating them!
+ *
+ * The results of this function are stored in the EState associated with the
+ * ExprContext (particularly, its ecxt_param_exec_vals); any pass-by-ref
+ * result Datums are allocated in the EState's per-query memory. The passed
+ * econtext can be any ExprContext belonging to that EState; which one is
+ * important only to the extent that the ExprContext's per-tuple memory
+ * context is used to evaluate any parameters passed down to the subplan.
+ * (Thus in principle, the shorter-lived the ExprContext the better, since
+ * that data isn't needed after we return. In practice, because initplan
+ * parameters are never more complex than Vars, Aggrefs, etc, evaluating them
+ * currently never leaks any memory anyway.)
* ----------------------------------------------------------------
*/
void
ExecSetParamPlan(SubPlanState *node, ExprContext *econtext)
{
- SubPlan *subplan = (SubPlan *) node->xprstate.expr;
+ SubPlan *subplan = node->subplan;
PlanState *planstate = node->planstate;
SubLinkType subLinkType = subplan->subLinkType;
+ EState *estate = planstate->state;
+ ScanDirection dir = estate->es_direction;
MemoryContext oldcontext;
TupleTableSlot *slot;
ListCell *pvar;
if (subLinkType == CTE_SUBLINK)
elog(ERROR, "CTE subplans should not be executed via ExecSetParamPlan");
+ /*
+ * Enforce forward scan direction regardless of caller. It's hard but not
+ * impossible to get here in backward scan, so make it work anyway.
+ */
+ estate->es_direction = ForwardScanDirection;
+
/* Initialize ArrayBuildStateAny in caller's context, if needed */
if (subLinkType == ARRAY_SUBLINK)
astate = initArrayResultAny(subplan->firstColType,
found = true;
/* stash away current value */
- Assert(subplan->firstColType == tdesc->attrs[0]->atttypid);
+ Assert(subplan->firstColType == TupleDescAttr(tdesc, 0)->atttypid);
dvalue = slot_getattr(slot, 1, &disnull);
astate = accumArrayResultAny(astate, dvalue, disnull,
subplan->firstColType, oldcontext);
*/
if (node->curTuple)
heap_freetuple(node->curTuple);
- node->curTuple = ExecCopySlotTuple(slot);
+ node->curTuple = ExecCopySlotHeapTuple(slot);
/*
* Now set all the setParam params from the columns of the tuple
}
MemoryContextSwitchTo(oldcontext);
+
+ /* restore scan direction */
+ estate->es_direction = dir;
+}
+
+/*
+ * ExecSetParamPlanMulti
+ *
+ * Apply ExecSetParamPlan to evaluate any not-yet-evaluated initplan output
+ * parameters whose ParamIDs are listed in "params". Any listed params that
+ * are not initplan outputs are ignored.
+ *
+ * As with ExecSetParamPlan, any ExprContext belonging to the current EState
+ * can be used, but in principle a shorter-lived ExprContext is better than a
+ * longer-lived one.
+ */
+void
+ExecSetParamPlanMulti(const Bitmapset *params, ExprContext *econtext)
+{
+ int paramid;
+
+ paramid = -1;
+ while ((paramid = bms_next_member(params, paramid)) >= 0)
+ {
+ ParamExecData *prm = &(econtext->ecxt_param_exec_vals[paramid]);
+
+ if (prm->execPlan != NULL)
+ {
+ /* Parameter not evaluated yet, so go do it */
+ ExecSetParamPlan(prm->execPlan, econtext);
+ /* ExecSetParamPlan should have processed this param... */
+ Assert(prm->execPlan == NULL);
+ }
+ }
}
/*
ExecReScanSetParamPlan(SubPlanState *node, PlanState *parent)
{
PlanState *planstate = node->planstate;
- SubPlan *subplan = (SubPlan *) node->xprstate.expr;
+ SubPlan *subplan = node->subplan;
EState *estate = parent->state;
ListCell *l;
SubPlan *subplan2;
Cost cost1;
Cost cost2;
+ ListCell *lc;
- asstate->xprstate.evalfunc = (ExprStateEvalFunc) ExecAlternativeSubPlan;
- asstate->xprstate.expr = (Expr *) asplan;
+ asstate->subplan = asplan;
/*
* Initialize subplans. (Can we get away with only initializing the one
* we're going to use?)
*/
- asstate->subplans = (List *) ExecInitExpr((Expr *) asplan->subplans,
- parent);
+ foreach(lc, asplan->subplans)
+ {
+ SubPlan *sp = lfirst_node(SubPlan, lc);
+ SubPlanState *sps = ExecInitSubPlan(sp, parent);
+
+ asstate->subplans = lappend(asstate->subplans, sps);
+ parent->subPlan = lappend(parent->subPlan, sps);
+ }
/*
* Select the one to be used. For this, we need an estimate of the number
* Note: in future we might consider changing to different subplans on the
* fly, in case the original rowcount estimate turns out to be way off.
*/
-static Datum
+Datum
ExecAlternativeSubPlan(AlternativeSubPlanState *node,
ExprContext *econtext,
bool *isNull)
{
/* Just pass control to the active subplan */
- SubPlanState *activesp = (SubPlanState *) list_nth(node->subplans,
- node->active);
-
- Assert(IsA(activesp, SubPlanState));
+ SubPlanState *activesp = list_nth_node(SubPlanState,
+ node->subplans, node->active);
return ExecSubPlan(activesp, econtext, isNull);
}
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