PostgreSQL Source Code  git master
nodeNestloop.c File Reference
#include "postgres.h"
#include "executor/execdebug.h"
#include "executor/nodeNestloop.h"
#include "miscadmin.h"
#include "utils/memutils.h"
Include dependency graph for nodeNestloop.c:

Go to the source code of this file.

Functions

static TupleTableSlotExecNestLoop (PlanState *pstate)
 
NestLoopStateExecInitNestLoop (NestLoop *node, EState *estate, int eflags)
 
void ExecEndNestLoop (NestLoopState *node)
 
void ExecReScanNestLoop (NestLoopState *node)
 

Function Documentation

◆ ExecEndNestLoop()

void ExecEndNestLoop ( NestLoopState node)

Definition at line 366 of file nodeNestloop.c.

References ExecClearTuple(), ExecEndNode(), ExecFreeExprContext(), innerPlanState, NestLoopState::js, NL1_printf, outerPlanState, JoinState::ps, and PlanState::ps_ResultTupleSlot.

Referenced by ExecEndNode().

367 {
368  NL1_printf("ExecEndNestLoop: %s\n",
369  "ending node processing");
370 
371  /*
372  * Free the exprcontext
373  */
374  ExecFreeExprContext(&node->js.ps);
375 
376  /*
377  * clean out the tuple table
378  */
380 
381  /*
382  * close down subplans
383  */
386 
387  NL1_printf("ExecEndNestLoop: %s\n",
388  "node processing ended");
389 }
PlanState ps
Definition: execnodes.h:1610
void ExecEndNode(PlanState *node)
Definition: execProcnode.c:523
TupleTableSlot * ExecClearTuple(TupleTableSlot *slot)
Definition: execTuples.c:439
void ExecFreeExprContext(PlanState *planstate)
Definition: execUtils.c:603
TupleTableSlot * ps_ResultTupleSlot
Definition: execnodes.h:883
#define outerPlanState(node)
Definition: execnodes.h:896
#define NL1_printf(s, a)
Definition: execdebug.h:77
JoinState js
Definition: execnodes.h:1627
#define innerPlanState(node)
Definition: execnodes.h:895

◆ ExecInitNestLoop()

NestLoopState* ExecInitNestLoop ( NestLoop node,
EState estate,
int  eflags 
)

Definition at line 263 of file nodeNestloop.c.

References Assert, elog, ERROR, EXEC_FLAG_BACKWARD, EXEC_FLAG_MARK, EXEC_FLAG_REWIND, ExecAssignExprContext(), ExecAssignProjectionInfo(), ExecAssignResultTypeFromTL(), ExecGetResultType(), ExecInitNode(), ExecInitNullTupleSlot(), ExecInitQual(), ExecInitResultTupleSlot(), ExecNestLoop(), PlanState::ExecProcNode, Join::inner_unique, innerPlan, innerPlanState, NestLoop::join, JOIN_ANTI, JOIN_INNER, JOIN_LEFT, JOIN_SEMI, Join::joinqual, Join::jointype, NestLoopState::js, makeNode, NestLoop::nestParams, NIL, NL1_printf, outerPlan, outerPlanState, Join::plan, PlanState::plan, JoinState::ps, Plan::qual, PlanState::qual, and PlanState::state.

Referenced by ExecInitNode().

264 {
265  NestLoopState *nlstate;
266 
267  /* check for unsupported flags */
268  Assert(!(eflags & (EXEC_FLAG_BACKWARD | EXEC_FLAG_MARK)));
269 
270  NL1_printf("ExecInitNestLoop: %s\n",
271  "initializing node");
272 
273  /*
274  * create state structure
275  */
276  nlstate = makeNode(NestLoopState);
277  nlstate->js.ps.plan = (Plan *) node;
278  nlstate->js.ps.state = estate;
279  nlstate->js.ps.ExecProcNode = ExecNestLoop;
280 
281  /*
282  * Miscellaneous initialization
283  *
284  * create expression context for node
285  */
286  ExecAssignExprContext(estate, &nlstate->js.ps);
287 
288  /*
289  * initialize child expressions
290  */
291  nlstate->js.ps.qual =
292  ExecInitQual(node->join.plan.qual, (PlanState *) nlstate);
293  nlstate->js.jointype = node->join.jointype;
294  nlstate->js.joinqual =
295  ExecInitQual(node->join.joinqual, (PlanState *) nlstate);
296 
297  /*
298  * initialize child nodes
299  *
300  * If we have no parameters to pass into the inner rel from the outer,
301  * tell the inner child that cheap rescans would be good. If we do have
302  * such parameters, then there is no point in REWIND support at all in the
303  * inner child, because it will always be rescanned with fresh parameter
304  * values.
305  */
306  outerPlanState(nlstate) = ExecInitNode(outerPlan(node), estate, eflags);
307  if (node->nestParams == NIL)
308  eflags |= EXEC_FLAG_REWIND;
309  else
310  eflags &= ~EXEC_FLAG_REWIND;
311  innerPlanState(nlstate) = ExecInitNode(innerPlan(node), estate, eflags);
312 
313  /*
314  * tuple table initialization
315  */
316  ExecInitResultTupleSlot(estate, &nlstate->js.ps);
317 
318  /*
319  * detect whether we need only consider the first matching inner tuple
320  */
321  nlstate->js.single_match = (node->join.inner_unique ||
322  node->join.jointype == JOIN_SEMI);
323 
324  /* set up null tuples for outer joins, if needed */
325  switch (node->join.jointype)
326  {
327  case JOIN_INNER:
328  case JOIN_SEMI:
329  break;
330  case JOIN_LEFT:
331  case JOIN_ANTI:
332  nlstate->nl_NullInnerTupleSlot =
333  ExecInitNullTupleSlot(estate,
335  break;
336  default:
337  elog(ERROR, "unrecognized join type: %d",
338  (int) node->join.jointype);
339  }
340 
341  /*
342  * initialize tuple type and projection info
343  */
344  ExecAssignResultTypeFromTL(&nlstate->js.ps);
345  ExecAssignProjectionInfo(&nlstate->js.ps, NULL);
346 
347  /*
348  * finally, wipe the current outer tuple clean.
349  */
350  nlstate->nl_NeedNewOuter = true;
351  nlstate->nl_MatchedOuter = false;
352 
353  NL1_printf("ExecInitNestLoop: %s\n",
354  "node initialized");
355 
356  return nlstate;
357 }
JoinType jointype
Definition: execnodes.h:1611
#define NIL
Definition: pg_list.h:69
List * qual
Definition: plannodes.h:145
bool nl_MatchedOuter
Definition: execnodes.h:1629
ExprState * joinqual
Definition: execnodes.h:1614
List * nestParams
Definition: plannodes.h:687
PlanState ps
Definition: execnodes.h:1610
bool nl_NeedNewOuter
Definition: execnodes.h:1628
bool single_match
Definition: execnodes.h:1612
EState * state
Definition: execnodes.h:852
ExprState * ExecInitQual(List *qual, PlanState *parent)
Definition: execExpr.c:160
void ExecAssignResultTypeFromTL(PlanState *planstate)
Definition: execUtils.c:448
JoinType jointype
Definition: plannodes.h:668
TupleTableSlot * ExecInitNullTupleSlot(EState *estate, TupleDesc tupType)
Definition: execTuples.c:866
Join join
Definition: plannodes.h:686
#define ERROR
Definition: elog.h:43
void ExecInitResultTupleSlot(EState *estate, PlanState *planstate)
Definition: execTuples.c:832
#define EXEC_FLAG_BACKWARD
Definition: executor.h:60
#define outerPlanState(node)
Definition: execnodes.h:896
#define innerPlan(node)
Definition: plannodes.h:173
void ExecAssignProjectionInfo(PlanState *planstate, TupleDesc inputDesc)
Definition: execUtils.c:495
#define EXEC_FLAG_REWIND
Definition: executor.h:59
#define outerPlan(node)
Definition: plannodes.h:174
static TupleTableSlot * ExecNestLoop(PlanState *pstate)
Definition: nodeNestloop.c:61
ExecProcNodeMtd ExecProcNode
Definition: execnodes.h:856
TupleTableSlot * nl_NullInnerTupleSlot
Definition: execnodes.h:1630
Plan * plan
Definition: execnodes.h:850
#define makeNode(_type_)
Definition: nodes.h:560
#define Assert(condition)
Definition: c.h:670
#define EXEC_FLAG_MARK
Definition: executor.h:61
void ExecAssignExprContext(EState *estate, PlanState *planstate)
Definition: execUtils.c:426
#define NL1_printf(s, a)
Definition: execdebug.h:77
TupleDesc ExecGetResultType(PlanState *planstate)
Definition: execUtils.c:477
ExprState * qual
Definition: execnodes.h:868
JoinState js
Definition: execnodes.h:1627
#define elog
Definition: elog.h:219
bool inner_unique
Definition: plannodes.h:669
#define innerPlanState(node)
Definition: execnodes.h:895
PlanState * ExecInitNode(Plan *node, EState *estate, int eflags)
Definition: execProcnode.c:139
List * joinqual
Definition: plannodes.h:670
Plan plan
Definition: plannodes.h:667

◆ ExecNestLoop()

static TupleTableSlot* ExecNestLoop ( PlanState pstate)
static

Definition at line 61 of file nodeNestloop.c.

References Assert, bms_add_member(), castNode, CHECK_FOR_INTERRUPTS, PlanState::chgParam, ExprContext::ecxt_innertuple, ExprContext::ecxt_outertuple, ExprContext::ecxt_param_exec_vals, ENL1_printf, ExecProcNode(), ExecProject(), ExecQual(), ExecReScan(), innerPlan, innerPlanState, InstrCountFiltered1, InstrCountFiltered2, IsA, ParamExecData::isnull, JOIN_ANTI, JOIN_LEFT, JoinState::joinqual, JoinState::jointype, NestLoopState::js, lfirst, NestLoop::nestParams, NestLoopState::nl_MatchedOuter, NestLoopState::nl_NeedNewOuter, NestLoopState::nl_NullInnerTupleSlot, OUTER_VAR, outerPlan, outerPlanState, NestLoopParam::paramno, NestLoopParam::paramval, PlanState::plan, JoinState::ps, PlanState::ps_ExprContext, PlanState::ps_ProjInfo, PlanState::qual, ResetExprContext, JoinState::single_match, slot_getattr(), TupIsNull, ParamExecData::value, Var::varattno, and Var::varno.

Referenced by ExecInitNestLoop().

62 {
63  NestLoopState *node = castNode(NestLoopState, pstate);
64  NestLoop *nl;
67  TupleTableSlot *outerTupleSlot;
68  TupleTableSlot *innerTupleSlot;
69  ExprState *joinqual;
70  ExprState *otherqual;
71  ExprContext *econtext;
72  ListCell *lc;
73 
75 
76  /*
77  * get information from the node
78  */
79  ENL1_printf("getting info from node");
80 
81  nl = (NestLoop *) node->js.ps.plan;
82  joinqual = node->js.joinqual;
83  otherqual = node->js.ps.qual;
84  outerPlan = outerPlanState(node);
85  innerPlan = innerPlanState(node);
86  econtext = node->js.ps.ps_ExprContext;
87 
88  /*
89  * Reset per-tuple memory context to free any expression evaluation
90  * storage allocated in the previous tuple cycle.
91  */
92  ResetExprContext(econtext);
93 
94  /*
95  * Ok, everything is setup for the join so now loop until we return a
96  * qualifying join tuple.
97  */
98  ENL1_printf("entering main loop");
99 
100  for (;;)
101  {
102  /*
103  * If we don't have an outer tuple, get the next one and reset the
104  * inner scan.
105  */
106  if (node->nl_NeedNewOuter)
107  {
108  ENL1_printf("getting new outer tuple");
109  outerTupleSlot = ExecProcNode(outerPlan);
110 
111  /*
112  * if there are no more outer tuples, then the join is complete..
113  */
114  if (TupIsNull(outerTupleSlot))
115  {
116  ENL1_printf("no outer tuple, ending join");
117  return NULL;
118  }
119 
120  ENL1_printf("saving new outer tuple information");
121  econtext->ecxt_outertuple = outerTupleSlot;
122  node->nl_NeedNewOuter = false;
123  node->nl_MatchedOuter = false;
124 
125  /*
126  * fetch the values of any outer Vars that must be passed to the
127  * inner scan, and store them in the appropriate PARAM_EXEC slots.
128  */
129  foreach(lc, nl->nestParams)
130  {
131  NestLoopParam *nlp = (NestLoopParam *) lfirst(lc);
132  int paramno = nlp->paramno;
133  ParamExecData *prm;
134 
135  prm = &(econtext->ecxt_param_exec_vals[paramno]);
136  /* Param value should be an OUTER_VAR var */
137  Assert(IsA(nlp->paramval, Var));
138  Assert(nlp->paramval->varno == OUTER_VAR);
139  Assert(nlp->paramval->varattno > 0);
140  prm->value = slot_getattr(outerTupleSlot,
141  nlp->paramval->varattno,
142  &(prm->isnull));
143  /* Flag parameter value as changed */
144  innerPlan->chgParam = bms_add_member(innerPlan->chgParam,
145  paramno);
146  }
147 
148  /*
149  * now rescan the inner plan
150  */
151  ENL1_printf("rescanning inner plan");
152  ExecReScan(innerPlan);
153  }
154 
155  /*
156  * we have an outerTuple, try to get the next inner tuple.
157  */
158  ENL1_printf("getting new inner tuple");
159 
160  innerTupleSlot = ExecProcNode(innerPlan);
161  econtext->ecxt_innertuple = innerTupleSlot;
162 
163  if (TupIsNull(innerTupleSlot))
164  {
165  ENL1_printf("no inner tuple, need new outer tuple");
166 
167  node->nl_NeedNewOuter = true;
168 
169  if (!node->nl_MatchedOuter &&
170  (node->js.jointype == JOIN_LEFT ||
171  node->js.jointype == JOIN_ANTI))
172  {
173  /*
174  * We are doing an outer join and there were no join matches
175  * for this outer tuple. Generate a fake join tuple with
176  * nulls for the inner tuple, and return it if it passes the
177  * non-join quals.
178  */
179  econtext->ecxt_innertuple = node->nl_NullInnerTupleSlot;
180 
181  ENL1_printf("testing qualification for outer-join tuple");
182 
183  if (otherqual == NULL || ExecQual(otherqual, econtext))
184  {
185  /*
186  * qualification was satisfied so we project and return
187  * the slot containing the result tuple using
188  * ExecProject().
189  */
190  ENL1_printf("qualification succeeded, projecting tuple");
191 
192  return ExecProject(node->js.ps.ps_ProjInfo);
193  }
194  else
195  InstrCountFiltered2(node, 1);
196  }
197 
198  /*
199  * Otherwise just return to top of loop for a new outer tuple.
200  */
201  continue;
202  }
203 
204  /*
205  * at this point we have a new pair of inner and outer tuples so we
206  * test the inner and outer tuples to see if they satisfy the node's
207  * qualification.
208  *
209  * Only the joinquals determine MatchedOuter status, but all quals
210  * must pass to actually return the tuple.
211  */
212  ENL1_printf("testing qualification");
213 
214  if (ExecQual(joinqual, econtext))
215  {
216  node->nl_MatchedOuter = true;
217 
218  /* In an antijoin, we never return a matched tuple */
219  if (node->js.jointype == JOIN_ANTI)
220  {
221  node->nl_NeedNewOuter = true;
222  continue; /* return to top of loop */
223  }
224 
225  /*
226  * If we only need to join to the first matching inner tuple, then
227  * consider returning this one, but after that continue with next
228  * outer tuple.
229  */
230  if (node->js.single_match)
231  node->nl_NeedNewOuter = true;
232 
233  if (otherqual == NULL || ExecQual(otherqual, econtext))
234  {
235  /*
236  * qualification was satisfied so we project and return the
237  * slot containing the result tuple using ExecProject().
238  */
239  ENL1_printf("qualification succeeded, projecting tuple");
240 
241  return ExecProject(node->js.ps.ps_ProjInfo);
242  }
243  else
244  InstrCountFiltered2(node, 1);
245  }
246  else
247  InstrCountFiltered1(node, 1);
248 
249  /*
250  * Tuple fails qual, so free per-tuple memory and try again.
251  */
252  ResetExprContext(econtext);
253 
254  ENL1_printf("qualification failed, looping");
255  }
256 }
JoinType jointype
Definition: execnodes.h:1611
#define IsA(nodeptr, _type_)
Definition: nodes.h:563
bool nl_MatchedOuter
Definition: execnodes.h:1629
ExprState * joinqual
Definition: execnodes.h:1614
ProjectionInfo * ps_ProjInfo
Definition: execnodes.h:885
List * nestParams
Definition: plannodes.h:687
PlanState ps
Definition: execnodes.h:1610
#define castNode(_type_, nodeptr)
Definition: nodes.h:581
bool nl_NeedNewOuter
Definition: execnodes.h:1628
ExprContext * ps_ExprContext
Definition: execnodes.h:884
bool single_match
Definition: execnodes.h:1612
void ExecReScan(PlanState *node)
Definition: execAmi.c:76
AttrNumber varattno
Definition: primnodes.h:168
static bool ExecQual(ExprState *state, ExprContext *econtext)
Definition: executor.h:356
Definition: primnodes.h:163
Var * paramval
Definition: plannodes.h:694
#define ENL1_printf(message)
Definition: execdebug.h:78
bool isnull
Definition: params.h:101
#define outerPlanState(node)
Definition: execnodes.h:896
#define innerPlan(node)
Definition: plannodes.h:173
TupleTableSlot * ecxt_innertuple
Definition: execnodes.h:199
ParamExecData * ecxt_param_exec_vals
Definition: execnodes.h:207
#define TupIsNull(slot)
Definition: tuptable.h:138
#define InstrCountFiltered1(node, delta)
Definition: execnodes.h:899
Bitmapset * chgParam
Definition: execnodes.h:878
#define outerPlan(node)
Definition: plannodes.h:174
Index varno
Definition: primnodes.h:166
static TupleTableSlot * ExecProcNode(PlanState *node)
Definition: executor.h:236
TupleTableSlot * nl_NullInnerTupleSlot
Definition: execnodes.h:1630
Plan * plan
Definition: execnodes.h:850
TupleTableSlot * ecxt_outertuple
Definition: execnodes.h:200
#define Assert(condition)
Definition: c.h:670
#define lfirst(lc)
Definition: pg_list.h:106
#define InstrCountFiltered2(node, delta)
Definition: execnodes.h:904
Bitmapset * bms_add_member(Bitmapset *a, int x)
Definition: bitmapset.c:698
ExprState * qual
Definition: execnodes.h:868
JoinState js
Definition: execnodes.h:1627
Datum slot_getattr(TupleTableSlot *slot, int attnum, bool *isnull)
Definition: heaptuple.c:1142
Datum value
Definition: params.h:100
#define CHECK_FOR_INTERRUPTS()
Definition: miscadmin.h:98
#define innerPlanState(node)
Definition: execnodes.h:895
#define OUTER_VAR
Definition: primnodes.h:154
static TupleTableSlot * ExecProject(ProjectionInfo *projInfo)
Definition: executor.h:319
#define ResetExprContext(econtext)
Definition: executor.h:461

◆ ExecReScanNestLoop()

void ExecReScanNestLoop ( NestLoopState node)

Definition at line 396 of file nodeNestloop.c.

References PlanState::chgParam, ExecReScan(), NestLoopState::nl_MatchedOuter, NestLoopState::nl_NeedNewOuter, outerPlan, and outerPlanState.

Referenced by ExecReScan().

397 {
399 
400  /*
401  * If outerPlan->chgParam is not null then plan will be automatically
402  * re-scanned by first ExecProcNode.
403  */
404  if (outerPlan->chgParam == NULL)
405  ExecReScan(outerPlan);
406 
407  /*
408  * innerPlan is re-scanned for each new outer tuple and MUST NOT be
409  * re-scanned from here or you'll get troubles from inner index scans when
410  * outer Vars are used as run-time keys...
411  */
412 
413  node->nl_NeedNewOuter = true;
414  node->nl_MatchedOuter = false;
415 }
bool nl_MatchedOuter
Definition: execnodes.h:1629
bool nl_NeedNewOuter
Definition: execnodes.h:1628
void ExecReScan(PlanState *node)
Definition: execAmi.c:76
#define outerPlanState(node)
Definition: execnodes.h:896
Bitmapset * chgParam
Definition: execnodes.h:878
#define outerPlan(node)
Definition: plannodes.h:174