/*-------------------------------------------------------------------------
*
* nodeSubplan.c
- * routines to support subselects
+ * routines to support sub-selects appearing in expressions
*
- * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
+ * This module is concerned with executing SubPlan expression nodes, which
+ * should not be confused with sub-SELECTs appearing in FROM. SubPlans are
+ * divided into "initplans", which are those that need only one evaluation per
+ * query (among other restrictions, this requires that they don't use any
+ * direct correlation variables from the parent plan level), and "regular"
+ * subplans, which are re-evaluated every time their result is required.
+ *
+ *
+ * Portions Copyright (c) 1996-2019, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/executor/nodeSubplan.c,v 1.58 2003/10/01 21:30:52 tgl Exp $
+ * src/backend/executor/nodeSubplan.c
*
*-------------------------------------------------------------------------
*/
* INTERFACE ROUTINES
* ExecSubPlan - process a subselect
* ExecInitSubPlan - initialize a subselect
- * ExecEndSubPlan - shut down a subselect
*/
#include "postgres.h"
-#include "access/heapam.h"
+#include <limits.h>
+#include <math.h>
+
+#include "access/htup_details.h"
#include "executor/executor.h"
#include "executor/nodeSubplan.h"
#include "nodes/makefuncs.h"
-#include "parser/parse_expr.h"
+#include "nodes/nodeFuncs.h"
+#include "miscadmin.h"
#include "utils/array.h"
-#include "utils/datum.h"
#include "utils/lsyscache.h"
+#include "utils/memutils.h"
static Datum ExecHashSubPlan(SubPlanState *node,
static Datum ExecScanSubPlan(SubPlanState *node,
ExprContext *econtext,
bool *isNull);
-static void buildSubPlanHash(SubPlanState *node);
-static bool findPartialMatch(TupleHashTable hashtable, TupleTableSlot *slot);
-static bool tupleAllNulls(HeapTuple tuple);
+static void buildSubPlanHash(SubPlanState *node, ExprContext *econtext);
+static bool findPartialMatch(TupleHashTable hashtable, TupleTableSlot *slot,
+ FmgrInfo *eqfunctions);
+static bool slotAllNulls(TupleTableSlot *slot);
+static bool slotNoNulls(TupleTableSlot *slot);
/* ----------------------------------------------------------------
* ExecSubPlan
+ *
+ * This is the main entry point for execution of a regular SubPlan.
* ----------------------------------------------------------------
*/
Datum
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;
- if (subplan->setParam != NIL)
+ CHECK_FOR_INTERRUPTS();
+
+ /* Set non-null as default */
+ *isNull = false;
+
+ /* Sanity checks */
+ if (subplan->subLinkType == CTE_SUBLINK)
+ elog(ERROR, "CTE subplans should not be executed via ExecSubPlan");
+ 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;
- ExprContext *innerecontext = node->innerecontext;
TupleTableSlot *slot;
- HeapTuple tup;
/* Shouldn't have any direct correlation Vars */
if (subplan->parParam != NIL || node->args != NIL)
elog(ERROR, "hashed subplan with direct correlation not supported");
/*
- * If first time through or we need to rescan the subplan, build the
- * hash table.
+ * If first time through or we need to rescan the subplan, build the hash
+ * table.
*/
if (node->hashtable == NULL || planstate->chgParam != NULL)
- buildSubPlanHash(node);
+ buildSubPlanHash(node, econtext);
/*
- * The result for an empty subplan is always FALSE; no need to
- * evaluate lefthand side.
+ * The result for an empty subplan is always FALSE; no need to evaluate
+ * lefthand side.
*/
*isNull = false;
if (!node->havehashrows && !node->havenullrows)
* have to set the econtext to use (hack alert!).
*/
node->projLeft->pi_exprContext = econtext;
- slot = ExecProject(node->projLeft, NULL);
- tup = slot->val;
+ slot = ExecProject(node->projLeft);
/*
- * Note: because we are typically called in a per-tuple context, we
- * have to explicitly clear the projected tuple before returning.
- * Otherwise, we'll have a double-free situation: the per-tuple
- * context will probably be reset before we're called again, and then
- * the tuple slot will think it still needs to free the tuple.
+ * Note: because we are typically called in a per-tuple context, we have
+ * to explicitly clear the projected tuple before returning. Otherwise,
+ * we'll have a double-free situation: the per-tuple context will probably
+ * be reset before we're called again, and then the tuple slot will think
+ * it still needs to free the tuple.
*/
/*
- * Since the hashtable routines will use innerecontext's per-tuple
- * memory as working memory, be sure to reset it for each tuple.
- */
- ResetExprContext(innerecontext);
-
- /*
- * If the LHS is all non-null, probe for an exact match in the main
- * hash table. If we find one, the result is TRUE. Otherwise, scan
- * the partly-null table to see if there are any rows that aren't
- * provably unequal to the LHS; if so, the result is UNKNOWN. (We
- * skip that part if we don't care about UNKNOWN.) Otherwise, the
- * result is FALSE.
+ * If the LHS is all non-null, probe for an exact match in the main hash
+ * table. If we find one, the result is TRUE. Otherwise, scan the
+ * partly-null table to see if there are any rows that aren't provably
+ * unequal to the LHS; if so, the result is UNKNOWN. (We skip that part
+ * if we don't care about UNKNOWN.) Otherwise, the result is FALSE.
*
* Note: the reason we can avoid a full scan of the main hash table is
- * that the combining operators are assumed never to yield NULL when
- * both inputs are non-null. If they were to do so, we might need to
- * produce UNKNOWN instead of FALSE because of an UNKNOWN result in
- * comparing the LHS to some main-table entry --- which is a
- * comparison we will not even make, unless there's a chance match of
- * hash keys.
+ * that the combining operators are assumed never to yield NULL when both
+ * inputs are non-null. If they were to do so, we might need to produce
+ * UNKNOWN instead of FALSE because of an UNKNOWN result in comparing the
+ * LHS to some main-table entry --- which is a comparison we will not even
+ * make, unless there's a chance match of hash keys.
*/
- if (HeapTupleNoNulls(tup))
+ if (slotNoNulls(slot))
{
if (node->havehashrows &&
- LookupTupleHashEntry(node->hashtable, slot, NULL) != NULL)
+ FindTupleHashEntry(node->hashtable,
+ slot,
+ node->cur_eq_comp,
+ node->lhs_hash_funcs) != NULL)
{
ExecClearTuple(slot);
return BoolGetDatum(true);
}
if (node->havenullrows &&
- findPartialMatch(node->hashnulls, slot))
+ findPartialMatch(node->hashnulls, slot, node->cur_eq_funcs))
{
ExecClearTuple(slot);
*isNull = true;
}
/*
- * When the LHS is partly or wholly NULL, we can never return TRUE. If
- * we don't care about UNKNOWN, just return FALSE. Otherwise, if the
- * LHS is wholly NULL, immediately return UNKNOWN. (Since the
- * combining operators are strict, the result could only be FALSE if
- * the sub-select were empty, but we already handled that case.)
- * Otherwise, we must scan both the main and partly-null tables to see
- * if there are any rows that aren't provably unequal to the LHS; if
- * so, the result is UNKNOWN. Otherwise, the result is FALSE.
+ * When the LHS is partly or wholly NULL, we can never return TRUE. If we
+ * don't care about UNKNOWN, just return FALSE. Otherwise, if the LHS is
+ * wholly NULL, immediately return UNKNOWN. (Since the combining
+ * operators are strict, the result could only be FALSE if the sub-select
+ * were empty, but we already handled that case.) Otherwise, we must scan
+ * both the main and partly-null tables to see if there are any rows that
+ * aren't provably unequal to the LHS; if so, the result is UNKNOWN.
+ * Otherwise, the result is FALSE.
*/
if (node->hashnulls == NULL)
{
ExecClearTuple(slot);
return BoolGetDatum(false);
}
- if (tupleAllNulls(tup))
+ if (slotAllNulls(slot))
{
ExecClearTuple(slot);
*isNull = true;
}
/* Scan partly-null table first, since more likely to get a match */
if (node->havenullrows &&
- findPartialMatch(node->hashnulls, slot))
+ findPartialMatch(node->hashnulls, slot, node->cur_eq_funcs))
{
ExecClearTuple(slot);
*isNull = true;
return BoolGetDatum(false);
}
if (node->havehashrows &&
- findPartialMatch(node->hashtable, slot))
+ findPartialMatch(node->hashtable, slot, node->cur_eq_funcs))
{
ExecClearTuple(slot);
*isNull = true;
ExprContext *econtext,
bool *isNull)
{
- SubPlan *subplan = (SubPlan *) node->xprstate.expr;
+ SubPlan *subplan = node->subplan;
PlanState *planstate = node->planstate;
SubLinkType subLinkType = subplan->subLinkType;
- bool useOr = subplan->useOr;
MemoryContext oldcontext;
TupleTableSlot *slot;
Datum result;
- bool found = false; /* TRUE if got at least one subplan tuple */
- List *pvar;
- List *lst;
- ArrayBuildState *astate = NULL;
+ bool found = false; /* true if got at least one subplan tuple */
+ ListCell *pvar;
+ ListCell *l;
+ ArrayBuildStateAny *astate = NULL;
/*
- * We are probably in a short-lived expression-evaluation context.
- * Switch to the child plan's per-query context for manipulating its
- * chgParam, calling ExecProcNode on it, etc.
+ * MULTIEXPR subplans, when "executed", just return NULL; but first we
+ * mark the subplan's output parameters as needing recalculation. (This
+ * is a bit of a hack: it relies on the subplan appearing later in its
+ * targetlist than any of the referencing Params, so that all the Params
+ * have been evaluated before we re-mark them for the next evaluation
+ * cycle. But in general resjunk tlist items appear after non-resjunk
+ * ones, so this should be safe.) Unlike ExecReScanSetParamPlan, we do
+ * *not* set bits in the parent plan node's chgParam, because we don't
+ * want to cause a rescan of the parent.
*/
- oldcontext = MemoryContextSwitchTo(node->sub_estate->es_query_cxt);
+ if (subLinkType == MULTIEXPR_SUBLINK)
+ {
+ EState *estate = node->parent->state;
+
+ foreach(l, subplan->setParam)
+ {
+ int paramid = lfirst_int(l);
+ ParamExecData *prm = &(estate->es_param_exec_vals[paramid]);
+
+ prm->execPlan = node;
+ }
+ *isNull = true;
+ return (Datum) 0;
+ }
+
+ /* Initialize ArrayBuildStateAny in caller's context, if needed */
+ if (subLinkType == ARRAY_SUBLINK)
+ astate = initArrayResultAny(subplan->firstColType,
+ CurrentMemoryContext, true);
+
+ /*
+ * We are probably in a short-lived expression-evaluation context. Switch
+ * to the per-query context for manipulating the child plan's chgParam,
+ * calling ExecProcNode on it, etc.
+ */
+ oldcontext = MemoryContextSwitchTo(econtext->ecxt_per_query_memory);
/*
* Set Params of this plan from parent plan correlation values. (Any
* calculation we have to do is done in the parent econtext, since the
* Param values don't need to have per-query lifetime.)
*/
- pvar = node->args;
- foreach(lst, subplan->parParam)
+ Assert(list_length(subplan->parParam) == list_length(node->args));
+
+ forboth(l, subplan->parParam, pvar, node->args)
{
- int paramid = lfirsti(lst);
+ int paramid = lfirst_int(l);
ParamExecData *prm = &(econtext->ecxt_param_exec_vals[paramid]);
- Assert(pvar != NIL);
prm->value = ExecEvalExprSwitchContext((ExprState *) lfirst(pvar),
econtext,
- &(prm->isnull),
- NULL);
- pvar = lnext(pvar);
+ &(prm->isnull));
planstate->chgParam = bms_add_member(planstate->chgParam, paramid);
}
- Assert(pvar == NIL);
- ExecReScan(planstate, NULL);
+ /*
+ * Now that we've set up its parameters, we can reset the subplan.
+ */
+ ExecReScan(planstate);
/*
- * For all sublink types except EXPR_SUBLINK and ARRAY_SUBLINK, the
- * result is boolean as are the results of the combining operators. We
- * combine results within a tuple (if there are multiple columns)
- * using OR semantics if "useOr" is true, AND semantics if not. We
- * then combine results across tuples (if the subplan produces more
- * than one) using OR semantics for ANY_SUBLINK or AND semantics for
- * ALL_SUBLINK. (MULTIEXPR_SUBLINK doesn't allow multiple tuples from
- * the subplan.) NULL results from the combining operators are handled
- * according to the usual SQL semantics for OR and AND. The result
- * for no input tuples is FALSE for ANY_SUBLINK, TRUE for ALL_SUBLINK,
- * NULL for MULTIEXPR_SUBLINK.
+ * For all sublink types except EXPR_SUBLINK and ARRAY_SUBLINK, the result
+ * is boolean as are the results of the combining operators. We combine
+ * results across tuples (if the subplan produces more than one) using OR
+ * semantics for ANY_SUBLINK or AND semantics for ALL_SUBLINK.
+ * (ROWCOMPARE_SUBLINK doesn't allow multiple tuples from the subplan.)
+ * NULL results from the combining operators are handled according to the
+ * usual SQL semantics for OR and AND. The result for no input tuples is
+ * FALSE for ANY_SUBLINK, TRUE for ALL_SUBLINK, NULL for
+ * ROWCOMPARE_SUBLINK.
*
* For EXPR_SUBLINK we require the subplan to produce no more than one
- * tuple, else an error is raised. For ARRAY_SUBLINK we allow the
- * subplan to produce more than one tuple. In either case, if zero
- * tuples are produced, we return NULL. Assuming we get a tuple, we
- * just use its first column (there can be only one non-junk column in
- * this case).
+ * tuple, else an error is raised. If zero tuples are produced, we return
+ * NULL. Assuming we get a tuple, we just use its first column (there can
+ * be only one non-junk column in this case).
+ *
+ * For ARRAY_SUBLINK we allow the subplan to produce any number of tuples,
+ * and form an array of the first column's values. Note in particular
+ * that we produce a zero-element array if no tuples are produced (this is
+ * a change from pre-8.3 behavior of returning NULL).
*/
result = BoolGetDatum(subLinkType == ALL_SUBLINK);
*isNull = false;
!TupIsNull(slot);
slot = ExecProcNode(planstate))
{
- HeapTuple tup = slot->val;
- TupleDesc tdesc = slot->ttc_tupleDescriptor;
- Datum rowresult = BoolGetDatum(!useOr);
- bool rownull = false;
- int col = 1;
- List *plst;
+ TupleDesc tdesc = slot->tts_tupleDescriptor;
+ Datum rowresult;
+ bool rownull;
+ int col;
+ ListCell *plst;
if (subLinkType == EXISTS_SUBLINK)
{
found = true;
/*
- * We need to copy the subplan's tuple in case the result is
- * of pass-by-ref type --- our return value will point into
- * this copied tuple! Can't use the subplan's instance of the
- * tuple since it won't still be valid after next
- * ExecProcNode() call. node->curTuple keeps track of the
- * copied tuple for eventual freeing.
+ * We need to copy the subplan's tuple in case the result is of
+ * pass-by-ref type --- our return value will point into this
+ * copied tuple! Can't use the subplan's instance of the tuple
+ * since it won't still be valid after next ExecProcNode() call.
+ * node->curTuple keeps track of the copied tuple for eventual
+ * freeing.
*/
- MemoryContextSwitchTo(econtext->ecxt_per_query_memory);
- tup = heap_copytuple(tup);
if (node->curTuple)
heap_freetuple(node->curTuple);
- node->curTuple = tup;
- MemoryContextSwitchTo(node->sub_estate->es_query_cxt);
+ node->curTuple = ExecCopySlotHeapTuple(slot);
- result = heap_getattr(tup, col, tdesc, isNull);
+ result = heap_getattr(node->curTuple, 1, tdesc, isNull);
/* keep scanning subplan to make sure there's only one tuple */
continue;
}
found = true;
/* stash away current value */
- dvalue = heap_getattr(tup, 1, tdesc, &disnull);
- astate = accumArrayResult(astate, dvalue, disnull,
- tdesc->attrs[0]->atttypid,
- oldcontext);
+ Assert(subplan->firstColType == TupleDescAttr(tdesc, 0)->atttypid);
+ dvalue = slot_getattr(slot, 1, &disnull);
+ astate = accumArrayResultAny(astate, dvalue, disnull,
+ subplan->firstColType, oldcontext);
/* keep scanning subplan to collect all values */
continue;
}
- /* cannot allow multiple input tuples for MULTIEXPR sublink either */
- if (subLinkType == MULTIEXPR_SUBLINK && found)
+ /* cannot allow multiple input tuples for ROWCOMPARE sublink either */
+ if (subLinkType == ROWCOMPARE_SUBLINK && found)
ereport(ERROR,
(errcode(ERRCODE_CARDINALITY_VIOLATION),
errmsg("more than one row returned by a subquery used as an expression")));
found = true;
/*
- * For ALL, ANY, and MULTIEXPR sublinks, iterate over combining
- * operators for columns of tuple.
+ * For ALL, ANY, and ROWCOMPARE sublinks, load up the Params
+ * representing the columns of the sub-select, and then evaluate the
+ * combining expression.
*/
- plst = subplan->paramIds;
- foreach(lst, node->exprs)
+ col = 1;
+ foreach(plst, subplan->paramIds)
{
- ExprState *exprstate = (ExprState *) lfirst(lst);
- int paramid = lfirsti(plst);
+ int paramid = lfirst_int(plst);
ParamExecData *prmdata;
- Datum expresult;
- bool expnull;
- /*
- * Load up the Param representing this column of the
- * sub-select.
- */
prmdata = &(econtext->ecxt_param_exec_vals[paramid]);
Assert(prmdata->execPlan == NULL);
- prmdata->value = heap_getattr(tup, col, tdesc,
- &(prmdata->isnull));
-
- /*
- * Now we can eval the combining operator for this column.
- */
- expresult = ExecEvalExprSwitchContext(exprstate, econtext,
- &expnull, NULL);
-
- /*
- * Combine the result into the row result as appropriate.
- */
- if (col == 1)
- {
- rowresult = expresult;
- rownull = expnull;
- }
- else if (useOr)
- {
- /* combine within row per OR semantics */
- if (expnull)
- rownull = true;
- else if (DatumGetBool(expresult))
- {
- rowresult = BoolGetDatum(true);
- rownull = false;
- break; /* needn't look at any more columns */
- }
- }
- else
- {
- /* combine within row per AND semantics */
- if (expnull)
- rownull = true;
- else if (!DatumGetBool(expresult))
- {
- rowresult = BoolGetDatum(false);
- rownull = false;
- break; /* needn't look at any more columns */
- }
- }
-
- plst = lnext(plst);
+ prmdata->value = slot_getattr(slot, col, &(prmdata->isnull));
col++;
}
+ rowresult = ExecEvalExprSwitchContext(node->testexpr, econtext,
+ &rownull);
+
if (subLinkType == ANY_SUBLINK)
{
/* combine across rows per OR semantics */
}
else
{
- /* must be MULTIEXPR_SUBLINK */
+ /* must be ROWCOMPARE_SUBLINK */
result = rowresult;
*isNull = rownull;
}
}
- if (!found)
+ MemoryContextSwitchTo(oldcontext);
+
+ if (subLinkType == ARRAY_SUBLINK)
+ {
+ /* We return the result in the caller's context */
+ result = makeArrayResultAny(astate, oldcontext, true);
+ }
+ else if (!found)
{
/*
- * deal with empty subplan result. result/isNull were previously
- * initialized correctly for all sublink types except EXPR, ARRAY,
- * and MULTIEXPR; for those, return NULL.
+ * deal with empty subplan result. result/isNull were previously
+ * initialized correctly for all sublink types except EXPR and
+ * ROWCOMPARE; for those, return NULL.
*/
if (subLinkType == EXPR_SUBLINK ||
- subLinkType == ARRAY_SUBLINK ||
- subLinkType == MULTIEXPR_SUBLINK)
+ subLinkType == ROWCOMPARE_SUBLINK)
{
result = (Datum) 0;
*isNull = true;
}
}
- else if (subLinkType == ARRAY_SUBLINK)
- {
- Assert(astate != NULL);
- /* We return the result in the caller's context */
- result = makeArrayResult(astate, oldcontext);
- }
-
- MemoryContextSwitchTo(oldcontext);
return result;
}
* buildSubPlanHash: load hash table by scanning subplan output.
*/
static void
-buildSubPlanHash(SubPlanState *node)
+buildSubPlanHash(SubPlanState *node, ExprContext *econtext)
{
- SubPlan *subplan = (SubPlan *) node->xprstate.expr;
+ SubPlan *subplan = node->subplan;
PlanState *planstate = node->planstate;
- int ncols = length(node->exprs);
+ int ncols = list_length(subplan->paramIds);
ExprContext *innerecontext = node->innerecontext;
- MemoryContext tempcxt = innerecontext->ecxt_per_tuple_memory;
MemoryContext oldcontext;
- int nbuckets;
+ long nbuckets;
TupleTableSlot *slot;
Assert(subplan->subLinkType == ANY_SUBLINK);
- Assert(!subplan->useOr);
/*
- * If we already had any hash tables, destroy 'em; then create empty
- * hash table(s).
+ * If we already had any hash tables, destroy 'em; then create empty hash
+ * table(s).
*
* If we need to distinguish accurately between FALSE and UNKNOWN (i.e.,
- * NULL) results of the IN operation, then we have to store subplan
- * output rows that are partly or wholly NULL. We store such rows in
- * a separate hash table that we expect will be much smaller than the
- * main table. (We can use hashing to eliminate partly-null rows that
- * are not distinct. We keep them separate to minimize the cost of
- * the inevitable full-table searches; see findPartialMatch.)
+ * NULL) results of the IN operation, then we have to store subplan output
+ * rows that are partly or wholly NULL. We store such rows in a separate
+ * hash table that we expect will be much smaller than the main table. (We
+ * can use hashing to eliminate partly-null rows that are not distinct. We
+ * keep them separate to minimize the cost of the inevitable full-table
+ * searches; see findPartialMatch.)
*
* If it's not necessary to distinguish FALSE and UNKNOWN, then we don't
* need to store subplan output rows that contain NULL.
*/
- MemoryContextReset(node->tablecxt);
+ MemoryContextReset(node->hashtablecxt);
node->hashtable = NULL;
node->hashnulls = NULL;
node->havehashrows = false;
node->havenullrows = false;
- nbuckets = (int) ceil(planstate->plan->plan_rows);
+ nbuckets = (long) Min(planstate->plan->plan_rows, (double) LONG_MAX);
if (nbuckets < 1)
nbuckets = 1;
- node->hashtable = BuildTupleHashTable(ncols,
+ node->hashtable = BuildTupleHashTable(node->parent,
+ node->descRight,
+ ncols,
node->keyColIdx,
- node->eqfunctions,
- node->hashfunctions,
+ node->tab_eq_funcoids,
+ node->tab_hash_funcs,
nbuckets,
- sizeof(TupleHashEntryData),
- node->tablecxt,
- tempcxt);
+ 0,
+ node->hashtablecxt,
+ node->hashtempcxt,
+ false);
if (!subplan->unknownEqFalse)
{
if (nbuckets < 1)
nbuckets = 1;
}
- node->hashnulls = BuildTupleHashTable(ncols,
+ node->hashnulls = BuildTupleHashTable(node->parent,
+ node->descRight,
+ ncols,
node->keyColIdx,
- node->eqfunctions,
- node->hashfunctions,
+ node->tab_eq_funcoids,
+ node->tab_hash_funcs,
nbuckets,
- sizeof(TupleHashEntryData),
- node->tablecxt,
- tempcxt);
+ 0,
+ node->hashtablecxt,
+ node->hashtempcxt,
+ false);
}
/*
- * We are probably in a short-lived expression-evaluation context.
- * Switch to the child plan's per-query context for calling
- * ExecProcNode.
+ * We are probably in a short-lived expression-evaluation context. Switch
+ * to the per-query context for manipulating the child plan.
*/
- oldcontext = MemoryContextSwitchTo(node->sub_estate->es_query_cxt);
+ oldcontext = MemoryContextSwitchTo(econtext->ecxt_per_query_memory);
/*
* Reset subplan to start.
*/
- ExecReScan(planstate, NULL);
+ ExecReScan(planstate);
/*
- * Scan the subplan and load the hash table(s). Note that when there
- * are duplicate rows coming out of the sub-select, only one copy is
- * stored.
+ * Scan the subplan and load the hash table(s). Note that when there are
+ * duplicate rows coming out of the sub-select, only one copy is stored.
*/
for (slot = ExecProcNode(planstate);
!TupIsNull(slot);
slot = ExecProcNode(planstate))
{
- HeapTuple tup = slot->val;
- TupleDesc tdesc = slot->ttc_tupleDescriptor;
int col = 1;
- List *plst;
+ ListCell *plst;
bool isnew;
/*
- * Load up the Params representing the raw sub-select outputs,
- * then form the projection tuple to store in the hashtable.
+ * Load up the Params representing the raw sub-select outputs, then
+ * form the projection tuple to store in the hashtable.
*/
foreach(plst, subplan->paramIds)
{
- int paramid = lfirsti(plst);
+ int paramid = lfirst_int(plst);
ParamExecData *prmdata;
prmdata = &(innerecontext->ecxt_param_exec_vals[paramid]);
Assert(prmdata->execPlan == NULL);
- prmdata->value = heap_getattr(tup, col, tdesc,
+ prmdata->value = slot_getattr(slot, col,
&(prmdata->isnull));
col++;
}
- slot = ExecProject(node->projRight, NULL);
- tup = slot->val;
+ slot = ExecProject(node->projRight);
/*
* If result contains any nulls, store separately or not at all.
- * (Since we know the projection tuple has no junk columns, we can
- * just look at the overall hasnull info bit, instead of groveling
- * through the columns.)
*/
- if (HeapTupleNoNulls(tup))
+ if (slotNoNulls(slot))
{
(void) LookupTupleHashEntry(node->hashtable, slot, &isnew);
node->havehashrows = true;
}
/*
- * Reset innerecontext after each inner tuple to free any memory
- * used in hash computation or comparison routines.
+ * Reset innerecontext after each inner tuple to free any memory used
+ * during ExecProject.
*/
ResetExprContext(innerecontext);
}
/*
- * Since the projected tuples are in the sub-query's context and not
- * the main context, we'd better clear the tuple slot before there's
- * any chance of a reset of the sub-query's context. Else we will
- * have the potential for a double free attempt.
+ * Since the projected tuples are in the sub-query's context and not the
+ * main context, we'd better clear the tuple slot before there's any
+ * chance of a reset of the sub-query's context. Else we will have the
+ * 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?
* We have to scan the whole hashtable; we can't usefully use hashkeys
* to guide probing, since we might get partial matches on tuples with
* hashkeys quite unrelated to what we'd get from the given tuple.
+ *
+ * Caller must provide the equality functions to use, since in cross-type
+ * cases these are different from the hashtable's internal functions.
*/
static bool
-findPartialMatch(TupleHashTable hashtable, TupleTableSlot *slot)
+findPartialMatch(TupleHashTable hashtable, TupleTableSlot *slot,
+ FmgrInfo *eqfunctions)
{
int numCols = hashtable->numCols;
AttrNumber *keyColIdx = hashtable->keyColIdx;
- HeapTuple tuple = slot->val;
- TupleDesc tupdesc = slot->ttc_tupleDescriptor;
TupleHashIterator hashiter;
TupleHashEntry entry;
- ResetTupleHashIterator(hashtable, &hashiter);
- while ((entry = ScanTupleHashTable(&hashiter)) != NULL)
+ InitTupleHashIterator(hashtable, &hashiter);
+ while ((entry = ScanTupleHashTable(hashtable, &hashiter)) != NULL)
{
- if (!execTuplesUnequal(entry->firstTuple,
- tuple,
- tupdesc,
+ CHECK_FOR_INTERRUPTS();
+
+ ExecStoreMinimalTuple(entry->firstTuple, hashtable->tableslot, false);
+ if (!execTuplesUnequal(slot, hashtable->tableslot,
numCols, keyColIdx,
- hashtable->eqfunctions,
+ eqfunctions,
hashtable->tempcxt))
+ {
+ TermTupleHashIterator(&hashiter);
return true;
+ }
}
+ /* No TermTupleHashIterator call needed here */
return false;
}
/*
- * tupleAllNulls: is the tuple completely NULL?
+ * slotAllNulls: is the slot completely NULL?
+ *
+ * This does not test for dropped columns, which is OK because we only
+ * use it on projected tuples.
+ */
+static bool
+slotAllNulls(TupleTableSlot *slot)
+{
+ int ncols = slot->tts_tupleDescriptor->natts;
+ int i;
+
+ for (i = 1; i <= ncols; i++)
+ {
+ if (!slot_attisnull(slot, i))
+ return false;
+ }
+ return true;
+}
+
+/*
+ * slotNoNulls: is the slot entirely not NULL?
+ *
+ * This does not test for dropped columns, which is OK because we only
+ * use it on projected tuples.
*/
static bool
-tupleAllNulls(HeapTuple tuple)
+slotNoNulls(TupleTableSlot *slot)
{
- int ncols = tuple->t_data->t_natts;
+ int ncols = slot->tts_tupleDescriptor->natts;
int i;
for (i = 1; i <= ncols; i++)
{
- if (!heap_attisnull(tuple, i))
+ if (slot_attisnull(slot, i))
return false;
}
return true;
/* ----------------------------------------------------------------
* ExecInitSubPlan
+ *
+ * Create a SubPlanState for a SubPlan; this is the SubPlan-specific part
+ * of ExecInitExpr(). We split it out so that it can be used for InitPlans
+ * as well as regular SubPlans. Note that we don't link the SubPlan into
+ * the parent's subPlan list, because that shouldn't happen for InitPlans.
+ * Instead, ExecInitExpr() does that one part.
* ----------------------------------------------------------------
*/
-void
-ExecInitSubPlan(SubPlanState *node, EState *estate)
+SubPlanState *
+ExecInitSubPlan(SubPlan *subplan, PlanState *parent)
{
- SubPlan *subplan = (SubPlan *) node->xprstate.expr;
- EState *sp_estate;
- MemoryContext oldcontext;
-
- /*
- * Do access checking on the rangetable entries in the subquery. Here,
- * we assume the subquery is a SELECT.
- */
- ExecCheckRTPerms(subplan->rtable, CMD_SELECT);
+ SubPlanState *sstate = makeNode(SubPlanState);
+ EState *estate = parent->state;
- /*
- * initialize my state
- */
- node->needShutdown = false;
- node->curTuple = NULL;
- node->projLeft = NULL;
- node->projRight = NULL;
- node->hashtable = NULL;
- node->hashnulls = NULL;
- node->tablecxt = NULL;
- node->innerecontext = NULL;
- node->keyColIdx = NULL;
- node->eqfunctions = NULL;
- node->hashfunctions = NULL;
+ sstate->subplan = subplan;
- /*
- * create an EState for the subplan
- *
- * The subquery needs its own EState because it has its own rangetable.
- * It shares our Param ID space, however. XXX if rangetable access
- * were done differently, the subquery could share our EState, which
- * would eliminate some thrashing about in this module...
- */
- sp_estate = CreateExecutorState();
- node->sub_estate = sp_estate;
+ /* Link the SubPlanState to already-initialized subplan */
+ sstate->planstate = (PlanState *) list_nth(estate->es_subplanstates,
+ subplan->plan_id - 1);
- oldcontext = MemoryContextSwitchTo(sp_estate->es_query_cxt);
+ /* ... and to its parent's state */
+ sstate->parent = parent;
- sp_estate->es_range_table = subplan->rtable;
- sp_estate->es_param_list_info = estate->es_param_list_info;
- sp_estate->es_param_exec_vals = estate->es_param_exec_vals;
- sp_estate->es_tupleTable =
- ExecCreateTupleTable(ExecCountSlotsNode(subplan->plan) + 10);
- sp_estate->es_snapshot = estate->es_snapshot;
- sp_estate->es_crosscheck_snapshot = estate->es_crosscheck_snapshot;
- sp_estate->es_instrument = estate->es_instrument;
+ /* Initialize subexpressions */
+ sstate->testexpr = ExecInitExpr((Expr *) subplan->testexpr, parent);
+ sstate->args = ExecInitExprList(subplan->args, parent);
/*
- * Start up the subplan (this is a very cut-down form of InitPlan())
+ * initialize my state
*/
- node->planstate = ExecInitNode(subplan->plan, sp_estate);
-
- node->needShutdown = true; /* now we need to shutdown the subplan */
-
- MemoryContextSwitchTo(oldcontext);
+ sstate->curTuple = NULL;
+ sstate->curArray = PointerGetDatum(NULL);
+ sstate->projLeft = NULL;
+ sstate->projRight = NULL;
+ sstate->hashtable = NULL;
+ sstate->hashnulls = NULL;
+ sstate->hashtablecxt = NULL;
+ 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;
+ sstate->cur_eq_funcs = NULL;
/*
- * If this plan is un-correlated or undirect correlated one and want
- * to set params for parent plan then mark parameters as needing
- * evaluation.
+ * If this is an initplan or MULTIEXPR subplan, it has output parameters
+ * that the parent plan will use, so mark those parameters as needing
+ * evaluation. We don't actually run the subplan until we first need one
+ * of its outputs.
*
- * Note that in the case of un-correlated subqueries we don't care about
- * setting parent->chgParam here: indices take care about it, for
- * others - it doesn't matter...
+ * A CTE subplan's output parameter is never to be evaluated in the normal
+ * way, so skip this in that case.
+ *
+ * Note that we don't set parent->chgParam here: the parent plan hasn't
+ * been run yet, so no need to force it to re-run.
*/
- if (subplan->setParam != NIL)
+ if (subplan->setParam != NIL && subplan->subLinkType != CTE_SUBLINK)
{
- List *lst;
+ ListCell *lst;
foreach(lst, subplan->setParam)
{
- int paramid = lfirsti(lst);
+ int paramid = lfirst_int(lst);
ParamExecData *prm = &(estate->es_param_exec_vals[paramid]);
- prm->execPlan = node;
+ prm->execPlan = sstate;
}
}
/*
- * If we are going to hash the subquery output, initialize relevant
- * stuff. (We don't create the hashtable until needed, though.)
+ * If we are going to hash the subquery output, initialize relevant stuff.
+ * (We don't create the hashtable until needed, though.)
*/
if (subplan->useHashTable)
{
int ncols,
i;
- TupleDesc tupDesc;
- TupleTable tupTable;
+ TupleDesc tupDescLeft;
+ TupleDesc tupDescRight;
TupleTableSlot *slot;
- List *lefttlist,
- *righttlist,
- *leftptlist,
- *rightptlist,
- *lexpr;
+ List *oplist,
+ *lefttlist,
+ *righttlist;
+ ListCell *l;
/* We need a memory context to hold the hash table(s) */
- node->tablecxt =
+ sstate->hashtablecxt =
AllocSetContextCreate(CurrentMemoryContext,
"Subplan HashTable Context",
- ALLOCSET_DEFAULT_MINSIZE,
- ALLOCSET_DEFAULT_INITSIZE,
- ALLOCSET_DEFAULT_MAXSIZE);
+ ALLOCSET_DEFAULT_SIZES);
+ /* and a small one for the hash tables to use as temp storage */
+ sstate->hashtempcxt =
+ AllocSetContextCreate(CurrentMemoryContext,
+ "Subplan HashTable Temp Context",
+ ALLOCSET_SMALL_SIZES);
/* and a short-lived exprcontext for function evaluation */
- node->innerecontext = CreateExprContext(estate);
+ sstate->innerecontext = CreateExprContext(estate);
/* Silly little array of column numbers 1..n */
- ncols = length(node->exprs);
- node->keyColIdx = (AttrNumber *) palloc(ncols * sizeof(AttrNumber));
+ ncols = list_length(subplan->paramIds);
+ sstate->keyColIdx = (AttrNumber *) palloc(ncols * sizeof(AttrNumber));
for (i = 0; i < ncols; i++)
- node->keyColIdx[i] = i + 1;
+ sstate->keyColIdx[i] = i + 1;
/*
* We use ExecProject to evaluate the lefthand and righthand
- * expression lists and form tuples. (You might think that we
- * could 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 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).
+ * expression lists and form tuples. (You might think that we could
+ * 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
+ * combining expressions to build tlists for the lefthand and
+ * righthand sides.
*
* We also extract the combining operators themselves to initialize
* the equality and hashing functions for the hash tables.
*/
+ if (IsA(subplan->testexpr, OpExpr))
+ {
+ /* single combining operator */
+ oplist = list_make1(subplan->testexpr);
+ }
+ else if (is_andclause(subplan->testexpr))
+ {
+ /* multiple combining operators */
+ oplist = castNode(BoolExpr, subplan->testexpr)->args;
+ }
+ else
+ {
+ /* shouldn't see anything else in a hashable subplan */
+ elog(ERROR, "unrecognized testexpr type: %d",
+ (int) nodeTag(subplan->testexpr));
+ oplist = NIL; /* keep compiler quiet */
+ }
+ Assert(list_length(oplist) == ncols);
+
lefttlist = righttlist = NIL;
- leftptlist = rightptlist = NIL;
- node->eqfunctions = (FmgrInfo *) palloc(ncols * sizeof(FmgrInfo));
- node->hashfunctions = (FmgrInfo *) palloc(ncols * sizeof(FmgrInfo));
+ 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));
+ sstate->cur_eq_funcs = (FmgrInfo *) palloc(ncols * sizeof(FmgrInfo));
i = 1;
- foreach(lexpr, node->exprs)
+ foreach(l, oplist)
{
- FuncExprState *fstate = (FuncExprState *) lfirst(lexpr);
- OpExpr *opexpr = (OpExpr *) fstate->xprstate.expr;
- ExprState *exstate;
+ OpExpr *opexpr = lfirst_node(OpExpr, l);
Expr *expr;
TargetEntry *tle;
- GenericExprState *tlestate;
- Oid hashfn;
+ Oid rhs_eq_oper;
+ Oid left_hashfn;
+ Oid right_hashfn;
- Assert(IsA(fstate, FuncExprState));
- Assert(IsA(opexpr, OpExpr));
- Assert(length(fstate->args) == 2);
+ Assert(list_length(opexpr->args) == 2);
/* Process lefthand argument */
- exstate = (ExprState *) lfirst(fstate->args);
- expr = exstate->expr;
- tle = makeTargetEntry(makeResdom(i,
- exprType((Node *) expr),
- exprTypmod((Node *) expr),
- NULL,
- false),
- expr);
- tlestate = makeNode(GenericExprState);
- tlestate->xprstate.expr = (Expr *) tle;
- tlestate->arg = exstate;
- lefttlist = lappend(lefttlist, tlestate);
- leftptlist = lappend(leftptlist, tle);
+ expr = (Expr *) linitial(opexpr->args);
+ tle = makeTargetEntry(expr,
+ i,
+ NULL,
+ false);
+ lefttlist = lappend(lefttlist, tle);
/* Process righthand argument */
- exstate = (ExprState *) lsecond(fstate->args);
- expr = exstate->expr;
- tle = makeTargetEntry(makeResdom(i,
- exprType((Node *) expr),
- exprTypmod((Node *) expr),
- NULL,
- false),
- expr);
- tlestate = makeNode(GenericExprState);
- tlestate->xprstate.expr = (Expr *) tle;
- tlestate->arg = exstate;
- righttlist = lappend(righttlist, tlestate);
- rightptlist = lappend(rightptlist, tle);
-
- /* Lookup the combining function */
- fmgr_info(opexpr->opfuncid, &node->eqfunctions[i - 1]);
- node->eqfunctions[i - 1].fn_expr = (Node *) opexpr;
-
- /* Lookup the associated hash function */
- hashfn = get_op_hash_function(opexpr->opno);
- if (!OidIsValid(hashfn))
+ expr = (Expr *) lsecond(opexpr->args);
+ tle = makeTargetEntry(expr,
+ i,
+ NULL,
+ false);
+ 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]);
+
+ /* Look up the equality function for the RHS type */
+ if (!get_compatible_hash_operators(opexpr->opno,
+ NULL, &rhs_eq_oper))
+ elog(ERROR, "could not find compatible hash operator for operator %u",
+ opexpr->opno);
+ fmgr_info(get_opcode(rhs_eq_oper), &sstate->tab_eq_funcs[i - 1]);
+
+ /* Lookup the associated hash functions */
+ if (!get_op_hash_functions(opexpr->opno,
+ &left_hashfn, &right_hashfn))
elog(ERROR, "could not find hash function for hash operator %u",
opexpr->opno);
- fmgr_info(hashfn, &node->hashfunctions[i - 1]);
+ fmgr_info(left_hashfn, &sstate->lhs_hash_funcs[i - 1]);
+ fmgr_info(right_hashfn, &sstate->tab_hash_funcs[i - 1]);
i++;
}
/*
- * Create a tupletable to hold these tuples. (Note: we never
- * bother to free the tupletable explicitly; that's okay because
- * it will never store raw disk tuples that might have associated
- * buffer pins. The only resource involved is memory, which will
- * be cleaned up by freeing the query context.)
+ * Construct tupdescs, slots and projection nodes for left and right
+ * sides. The lefthand expressions will be evaluated in the parent
+ * plan node's exprcontext, which we don't have access to here.
+ * Fortunately we can just pass NULL for now and fill it in later
+ * (hack alert!). The righthand expressions will be evaluated in our
+ * own innerecontext.
*/
- tupTable = ExecCreateTupleTable(2);
+ tupDescLeft = ExecTypeFromTL(lefttlist);
+ slot = ExecInitExtraTupleSlot(estate, tupDescLeft, &TTSOpsVirtual);
+ sstate->projLeft = ExecBuildProjectionInfo(lefttlist,
+ NULL,
+ slot,
+ parent,
+ NULL);
+
+ sstate->descRight = tupDescRight = ExecTypeFromTL(righttlist);
+ slot = ExecInitExtraTupleSlot(estate, tupDescRight, &TTSOpsVirtual);
+ sstate->projRight = ExecBuildProjectionInfo(righttlist,
+ sstate->innerecontext,
+ slot,
+ sstate->planstate,
+ NULL);
/*
- * Construct tupdescs, slots and projection nodes for left and
- * right sides. The lefthand expressions will be evaluated in the
- * parent plan node's exprcontext, which we don't have access to
- * here. Fortunately we can just pass NULL for now and fill it in
- * later (hack alert!). The righthand expressions will be
- * evaluated in our own innerecontext.
+ * Create comparator for lookups of rows in the table (potentially
+ * across-type comparison).
*/
- tupDesc = ExecTypeFromTL(leftptlist, false);
- slot = ExecAllocTableSlot(tupTable);
- ExecSetSlotDescriptor(slot, tupDesc, true);
- node->projLeft = ExecBuildProjectionInfo(lefttlist,
- NULL,
- slot);
-
- tupDesc = ExecTypeFromTL(rightptlist, false);
- slot = ExecAllocTableSlot(tupTable);
- ExecSetSlotDescriptor(slot, tupDesc, true);
- node->projRight = ExecBuildProjectionInfo(righttlist,
- node->innerecontext,
- slot);
+ sstate->cur_eq_comp = ExecBuildGroupingEqual(tupDescLeft, tupDescRight,
+ &TTSOpsVirtual, &TTSOpsMinimalTuple,
+ ncols,
+ sstate->keyColIdx,
+ sstate->tab_eq_funcoids,
+ parent);
+
}
+
+ return sstate;
}
/* ----------------------------------------------------------------
* ExecSetParamPlan
*
- * Executes an InitPlan subplan and sets its output parameters.
+ * Executes a subplan and sets its output parameters.
*
- * This is called from ExecEvalParam() when the value of a PARAM_EXEC
+ * This is called from ExecEvalParamExec() when the value of a PARAM_EXEC
* parameter is requested and the param's execPlan field is set (indicating
- * that the param has not yet been evaluated). This allows lazy evaluation
+ * that the param has not yet been evaluated). This allows lazy evaluation
* 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;
- List *lst;
+ ListCell *pvar;
+ ListCell *l;
bool found = false;
- ArrayBuildState *astate = NULL;
-
- /*
- * Must switch to child query's per-query memory context.
- */
- oldcontext = MemoryContextSwitchTo(node->sub_estate->es_query_cxt);
+ ArrayBuildStateAny *astate = NULL;
if (subLinkType == ANY_SUBLINK ||
subLinkType == ALL_SUBLINK)
elog(ERROR, "ANY/ALL subselect unsupported as initplan");
+ 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,
+ CurrentMemoryContext, true);
+
+ /*
+ * Must switch to per-query memory context.
+ */
+ oldcontext = MemoryContextSwitchTo(econtext->ecxt_per_query_memory);
+
+ /*
+ * Set Params of this plan from parent plan correlation values. (Any
+ * calculation we have to do is done in the parent econtext, since the
+ * Param values don't need to have per-query lifetime.) Currently, we
+ * expect only MULTIEXPR_SUBLINK plans to have any correlation values.
+ */
+ Assert(subplan->parParam == NIL || subLinkType == MULTIEXPR_SUBLINK);
+ Assert(list_length(subplan->parParam) == list_length(node->args));
- if (planstate->chgParam != NULL)
- ExecReScan(planstate, NULL);
+ forboth(l, subplan->parParam, pvar, node->args)
+ {
+ int paramid = lfirst_int(l);
+ ParamExecData *prm = &(econtext->ecxt_param_exec_vals[paramid]);
+
+ prm->value = ExecEvalExprSwitchContext((ExprState *) lfirst(pvar),
+ econtext,
+ &(prm->isnull));
+ planstate->chgParam = bms_add_member(planstate->chgParam, paramid);
+ }
+ /*
+ * Run the plan. (If it needs to be rescanned, the first ExecProcNode
+ * call will take care of that.)
+ */
for (slot = ExecProcNode(planstate);
!TupIsNull(slot);
slot = ExecProcNode(planstate))
{
- HeapTuple tup = slot->val;
- TupleDesc tdesc = slot->ttc_tupleDescriptor;
+ TupleDesc tdesc = slot->tts_tupleDescriptor;
int i = 1;
if (subLinkType == EXISTS_SUBLINK)
{
- /* There can be only one param... */
- int paramid = lfirsti(subplan->setParam);
+ /* There can be only one setParam... */
+ int paramid = linitial_int(subplan->setParam);
ParamExecData *prm = &(econtext->ecxt_param_exec_vals[paramid]);
prm->execPlan = NULL;
found = true;
/* stash away current value */
- dvalue = heap_getattr(tup, 1, tdesc, &disnull);
- astate = accumArrayResult(astate, dvalue, disnull,
- tdesc->attrs[0]->atttypid,
- oldcontext);
+ Assert(subplan->firstColType == TupleDescAttr(tdesc, 0)->atttypid);
+ dvalue = slot_getattr(slot, 1, &disnull);
+ astate = accumArrayResultAny(astate, dvalue, disnull,
+ subplan->firstColType, oldcontext);
/* keep scanning subplan to collect all values */
continue;
}
if (found &&
(subLinkType == EXPR_SUBLINK ||
- subLinkType == MULTIEXPR_SUBLINK))
+ subLinkType == MULTIEXPR_SUBLINK ||
+ subLinkType == ROWCOMPARE_SUBLINK))
ereport(ERROR,
(errcode(ERRCODE_CARDINALITY_VIOLATION),
errmsg("more than one row returned by a subquery used as an expression")));
found = true;
/*
- * We need to copy the subplan's tuple into our own context, in
- * case any of the params are pass-by-ref type --- the pointers
- * stored in the param structs will point at this copied tuple!
- * node->curTuple keeps track of the copied tuple for eventual
- * freeing.
+ * We need to copy the subplan's tuple into our own context, in case
+ * any of the params are pass-by-ref type --- the pointers stored in
+ * the param structs will point at this copied tuple! node->curTuple
+ * keeps track of the copied tuple for eventual freeing.
*/
- MemoryContextSwitchTo(econtext->ecxt_per_query_memory);
- tup = heap_copytuple(tup);
if (node->curTuple)
heap_freetuple(node->curTuple);
- node->curTuple = tup;
- MemoryContextSwitchTo(node->sub_estate->es_query_cxt);
+ node->curTuple = ExecCopySlotHeapTuple(slot);
/*
* Now set all the setParam params from the columns of the tuple
*/
- foreach(lst, subplan->setParam)
+ foreach(l, subplan->setParam)
{
- int paramid = lfirsti(lst);
+ int paramid = lfirst_int(l);
ParamExecData *prm = &(econtext->ecxt_param_exec_vals[paramid]);
prm->execPlan = NULL;
- prm->value = heap_getattr(tup, i, tdesc, &(prm->isnull));
+ prm->value = heap_getattr(node->curTuple, i, tdesc,
+ &(prm->isnull));
i++;
}
}
- if (!found)
+ if (subLinkType == ARRAY_SUBLINK)
+ {
+ /* There can be only one setParam... */
+ int paramid = linitial_int(subplan->setParam);
+ ParamExecData *prm = &(econtext->ecxt_param_exec_vals[paramid]);
+
+ /*
+ * We build the result array in query context so it won't disappear;
+ * to avoid leaking memory across repeated calls, we have to remember
+ * the latest value, much as for curTuple above.
+ */
+ if (node->curArray != PointerGetDatum(NULL))
+ pfree(DatumGetPointer(node->curArray));
+ node->curArray = makeArrayResultAny(astate,
+ econtext->ecxt_per_query_memory,
+ true);
+ prm->execPlan = NULL;
+ prm->value = node->curArray;
+ prm->isnull = false;
+ }
+ else if (!found)
{
if (subLinkType == EXISTS_SUBLINK)
{
- /* There can be only one param... */
- int paramid = lfirsti(subplan->setParam);
+ /* There can be only one setParam... */
+ int paramid = linitial_int(subplan->setParam);
ParamExecData *prm = &(econtext->ecxt_param_exec_vals[paramid]);
prm->execPlan = NULL;
}
else
{
- foreach(lst, subplan->setParam)
+ /* For other sublink types, set all the output params to NULL */
+ foreach(l, subplan->setParam)
{
- int paramid = lfirsti(lst);
+ int paramid = lfirst_int(l);
ParamExecData *prm = &(econtext->ecxt_param_exec_vals[paramid]);
prm->execPlan = NULL;
}
}
}
- else if (subLinkType == ARRAY_SUBLINK)
- {
- /* There can be only one param... */
- int paramid = lfirsti(subplan->setParam);
- ParamExecData *prm = &(econtext->ecxt_param_exec_vals[paramid]);
-
- Assert(astate != NULL);
- prm->execPlan = NULL;
- /* We build the result in query context so it won't disappear */
- prm->value = makeArrayResult(astate, econtext->ecxt_per_query_memory);
- prm->isnull = false;
- }
MemoryContextSwitchTo(oldcontext);
+
+ /* restore scan direction */
+ estate->es_direction = dir;
}
-/* ----------------------------------------------------------------
- * ExecEndSubPlan
- * ----------------------------------------------------------------
+/*
+ * 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
-ExecEndSubPlan(SubPlanState *node)
+ExecSetParamPlanMulti(const Bitmapset *params, ExprContext *econtext)
{
- if (node->needShutdown)
+ int paramid;
+
+ paramid = -1;
+ while ((paramid = bms_next_member(params, paramid)) >= 0)
{
- MemoryContext oldcontext;
-
- oldcontext = MemoryContextSwitchTo(node->sub_estate->es_query_cxt);
- ExecEndPlan(node->planstate, node->sub_estate);
- MemoryContextSwitchTo(oldcontext);
- FreeExecutorState(node->sub_estate);
- node->sub_estate = NULL;
- node->planstate = NULL;
- node->needShutdown = false;
+ 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;
- List *lst;
+ ListCell *l;
/* sanity checks */
if (subplan->parParam != NIL)
elog(ERROR, "extParam set of initplan is empty");
/*
- * Don't actually re-scan: ExecSetParamPlan does it if needed.
+ * Don't actually re-scan: it'll happen inside ExecSetParamPlan if needed.
*/
/*
- * Mark this subplan's output parameters as needing recalculation
+ * Mark this subplan's output parameters as needing recalculation.
+ *
+ * CTE subplans are never executed via parameter recalculation; instead
+ * they get run when called by nodeCtescan.c. So don't mark the output
+ * parameter of a CTE subplan as dirty, but do set the chgParam bit for it
+ * so that dependent plan nodes will get told to rescan.
*/
- foreach(lst, subplan->setParam)
+ foreach(l, subplan->setParam)
{
- int paramid = lfirsti(lst);
+ int paramid = lfirst_int(l);
ParamExecData *prm = &(estate->es_param_exec_vals[paramid]);
- prm->execPlan = node;
+ if (subplan->subLinkType != CTE_SUBLINK)
+ prm->execPlan = node;
+
parent->chgParam = bms_add_member(parent->chgParam, paramid);
}
}
+
+
+/*
+ * ExecInitAlternativeSubPlan
+ *
+ * Initialize for execution of one of a set of alternative subplans.
+ */
+AlternativeSubPlanState *
+ExecInitAlternativeSubPlan(AlternativeSubPlan *asplan, PlanState *parent)
+{
+ AlternativeSubPlanState *asstate = makeNode(AlternativeSubPlanState);
+ double num_calls;
+ SubPlan *subplan1;
+ SubPlan *subplan2;
+ Cost cost1;
+ Cost cost2;
+ ListCell *lc;
+
+ asstate->subplan = asplan;
+
+ /*
+ * Initialize subplans. (Can we get away with only initializing the one
+ * we're going to use?)
+ */
+ 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
+ * of executions of the subplan. We use the number of output rows
+ * expected from the parent plan node. This is a good estimate if we are
+ * in the parent's targetlist, and an underestimate (but probably not by
+ * more than a factor of 2) if we are in the qual.
+ */
+ num_calls = parent->plan->plan_rows;
+
+ /*
+ * The planner saved enough info so that we don't have to work very hard
+ * to estimate the total cost, given the number-of-calls estimate.
+ */
+ Assert(list_length(asplan->subplans) == 2);
+ subplan1 = (SubPlan *) linitial(asplan->subplans);
+ subplan2 = (SubPlan *) lsecond(asplan->subplans);
+
+ cost1 = subplan1->startup_cost + num_calls * subplan1->per_call_cost;
+ cost2 = subplan2->startup_cost + num_calls * subplan2->per_call_cost;
+
+ if (cost1 < cost2)
+ asstate->active = 0;
+ else
+ asstate->active = 1;
+
+ return asstate;
+}
+
+/*
+ * ExecAlternativeSubPlan
+ *
+ * Execute one of a set of alternative subplans.
+ *
+ * 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.
+ */
+Datum
+ExecAlternativeSubPlan(AlternativeSubPlanState *node,
+ ExprContext *econtext,
+ bool *isNull)
+{
+ /* Just pass control to the active subplan */
+ SubPlanState *activesp = list_nth_node(SubPlanState,
+ node->subplans, node->active);
+
+ return ExecSubPlan(activesp, econtext, isNull);
+}
projects / postgresql / blobdiff