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nodeIndexonlyscan.c File Reference
Include dependency graph for nodeIndexonlyscan.c:

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Functions

static TupleTableSlotIndexOnlyNext (IndexOnlyScanState *node)
 
static void StoreIndexTuple (TupleTableSlot *slot, IndexTuple itup, TupleDesc itupdesc)
 
static bool IndexOnlyRecheck (IndexOnlyScanState *node, TupleTableSlot *slot)
 
TupleTableSlotExecIndexOnlyScan (IndexOnlyScanState *node)
 
void ExecReScanIndexOnlyScan (IndexOnlyScanState *node)
 
void ExecEndIndexOnlyScan (IndexOnlyScanState *node)
 
void ExecIndexOnlyMarkPos (IndexOnlyScanState *node)
 
void ExecIndexOnlyRestrPos (IndexOnlyScanState *node)
 
IndexOnlyScanStateExecInitIndexOnlyScan (IndexOnlyScan *node, EState *estate, int eflags)
 
void ExecIndexOnlyScanEstimate (IndexOnlyScanState *node, ParallelContext *pcxt)
 
void ExecIndexOnlyScanInitializeDSM (IndexOnlyScanState *node, ParallelContext *pcxt)
 
void ExecIndexOnlyScanInitializeWorker (IndexOnlyScanState *node, shm_toc *toc)
 

Function Documentation

void ExecEndIndexOnlyScan ( IndexOnlyScanState node)

Definition at line 382 of file nodeIndexonlyscan.c.

References ExecClearTuple(), ExecCloseScanRelation(), ExecFreeExprContext(), FreeExprContext(), index_close(), index_endscan(), InvalidBuffer, IndexOnlyScanState::ioss_RelationDesc, IndexOnlyScanState::ioss_RuntimeContext, IndexOnlyScanState::ioss_ScanDesc, IndexOnlyScanState::ioss_VMBuffer, NoLock, ScanState::ps, PlanState::ps_ResultTupleSlot, ReleaseBuffer(), IndexOnlyScanState::ss, ScanState::ss_currentRelation, and ScanState::ss_ScanTupleSlot.

Referenced by ExecEndNode().

383 {
384  Relation indexRelationDesc;
385  IndexScanDesc indexScanDesc;
386  Relation relation;
387 
388  /*
389  * extract information from the node
390  */
391  indexRelationDesc = node->ioss_RelationDesc;
392  indexScanDesc = node->ioss_ScanDesc;
393  relation = node->ss.ss_currentRelation;
394 
395  /* Release VM buffer pin, if any. */
396  if (node->ioss_VMBuffer != InvalidBuffer)
397  {
400  }
401 
402  /*
403  * Free the exprcontext(s) ... now dead code, see ExecFreeExprContext
404  */
405 #ifdef NOT_USED
406  ExecFreeExprContext(&node->ss.ps);
407  if (node->ioss_RuntimeContext)
409 #endif
410 
411  /*
412  * clear out tuple table slots
413  */
416 
417  /*
418  * close the index relation (no-op if we didn't open it)
419  */
420  if (indexScanDesc)
421  index_endscan(indexScanDesc);
422  if (indexRelationDesc)
423  index_close(indexRelationDesc, NoLock);
424 
425  /*
426  * close the heap relation.
427  */
428  ExecCloseScanRelation(relation);
429 }
TupleTableSlot * ExecClearTuple(TupleTableSlot *slot)
Definition: execTuples.c:439
#define InvalidBuffer
Definition: buf.h:25
TupleTableSlot * ss_ScanTupleSlot
Definition: execnodes.h:1293
void ReleaseBuffer(Buffer buffer)
Definition: bufmgr.c:3309
Relation ss_currentRelation
Definition: execnodes.h:1291
void ExecFreeExprContext(PlanState *planstate)
Definition: execUtils.c:686
PlanState ps
Definition: execnodes.h:1290
TupleTableSlot * ps_ResultTupleSlot
Definition: execnodes.h:1079
ExprContext * ioss_RuntimeContext
Definition: execnodes.h:1429
#define NoLock
Definition: lockdefs.h:34
IndexScanDesc ioss_ScanDesc
Definition: execnodes.h:1431
void index_endscan(IndexScanDesc scan)
Definition: indexam.c:340
void FreeExprContext(ExprContext *econtext, bool isCommit)
Definition: execUtils.c:340
Relation ioss_RelationDesc
Definition: execnodes.h:1430
void ExecCloseScanRelation(Relation scanrel)
Definition: execUtils.c:831
void index_close(Relation relation, LOCKMODE lockmode)
Definition: indexam.c:176
void ExecIndexOnlyMarkPos ( IndexOnlyScanState node)

Definition at line 436 of file nodeIndexonlyscan.c.

References index_markpos(), and IndexOnlyScanState::ioss_ScanDesc.

Referenced by ExecMarkPos().

437 {
439 }
void index_markpos(IndexScanDesc scan)
Definition: indexam.c:370
IndexScanDesc ioss_ScanDesc
Definition: execnodes.h:1431
void ExecIndexOnlyRestrPos ( IndexOnlyScanState node)

Definition at line 446 of file nodeIndexonlyscan.c.

References index_restrpos(), and IndexOnlyScanState::ioss_ScanDesc.

Referenced by ExecRestrPos().

447 {
449 }
void index_restrpos(IndexScanDesc scan)
Definition: indexam.c:395
IndexScanDesc ioss_ScanDesc
Definition: execnodes.h:1431
TupleTableSlot* ExecIndexOnlyScan ( IndexOnlyScanState node)

Definition at line 307 of file nodeIndexonlyscan.c.

References ExecReScan(), ExecScan(), IndexOnlyNext(), IndexOnlyRecheck(), IndexOnlyScanState::ioss_NumRuntimeKeys, IndexOnlyScanState::ioss_RuntimeKeysReady, and IndexOnlyScanState::ss.

Referenced by ExecProcNode().

308 {
309  /*
310  * If we have runtime keys and they've not already been set up, do it now.
311  */
312  if (node->ioss_NumRuntimeKeys != 0 && !node->ioss_RuntimeKeysReady)
313  ExecReScan((PlanState *) node);
314 
315  return ExecScan(&node->ss,
318 }
bool ioss_RuntimeKeysReady
Definition: execnodes.h:1428
TupleTableSlot * ExecScan(ScanState *node, ExecScanAccessMtd accessMtd, ExecScanRecheckMtd recheckMtd)
Definition: execScan.c:121
void ExecReScan(PlanState *node)
Definition: execAmi.c:74
static bool IndexOnlyRecheck(IndexOnlyScanState *node, TupleTableSlot *slot)
TupleTableSlot *(* ExecScanAccessMtd)(ScanState *node)
Definition: executor.h:272
bool(* ExecScanRecheckMtd)(ScanState *node, TupleTableSlot *slot)
Definition: executor.h:273
static TupleTableSlot * IndexOnlyNext(IndexOnlyScanState *node)
void ExecIndexOnlyScanEstimate ( IndexOnlyScanState node,
ParallelContext pcxt 
)

Definition at line 624 of file nodeIndexonlyscan.c.

References EState::es_snapshot, ParallelContext::estimator, index_parallelscan_estimate(), IndexOnlyScanState::ioss_PscanLen, IndexOnlyScanState::ioss_RelationDesc, ScanState::ps, shm_toc_estimate_chunk, shm_toc_estimate_keys, IndexOnlyScanState::ss, and PlanState::state.

Referenced by ExecParallelEstimate().

626 {
627  EState *estate = node->ss.ps.state;
628 
630  estate->es_snapshot);
632  shm_toc_estimate_keys(&pcxt->estimator, 1);
633 }
shm_toc_estimator estimator
Definition: parallel.h:42
Snapshot es_snapshot
Definition: execnodes.h:372
EState * state
Definition: execnodes.h:1051
#define shm_toc_estimate_chunk(e, sz)
Definition: shm_toc.h:49
Size index_parallelscan_estimate(Relation indexRelation, Snapshot snapshot)
Definition: indexam.c:417
PlanState ps
Definition: execnodes.h:1290
Relation ioss_RelationDesc
Definition: execnodes.h:1430
#define shm_toc_estimate_keys(e, cnt)
Definition: shm_toc.h:52
void ExecIndexOnlyScanInitializeDSM ( IndexOnlyScanState node,
ParallelContext pcxt 
)

Definition at line 642 of file nodeIndexonlyscan.c.

References EState::es_snapshot, index_beginscan_parallel(), index_parallelscan_initialize(), index_rescan(), InvalidBuffer, IndexOnlyScanState::ioss_NumOrderByKeys, IndexOnlyScanState::ioss_NumRuntimeKeys, IndexOnlyScanState::ioss_NumScanKeys, IndexOnlyScanState::ioss_OrderByKeys, IndexOnlyScanState::ioss_PscanLen, IndexOnlyScanState::ioss_RelationDesc, IndexOnlyScanState::ioss_RuntimeKeysReady, IndexOnlyScanState::ioss_ScanDesc, IndexOnlyScanState::ioss_ScanKeys, IndexOnlyScanState::ioss_VMBuffer, PlanState::plan, Plan::plan_node_id, ScanState::ps, shm_toc_allocate(), shm_toc_insert(), IndexOnlyScanState::ss, ScanState::ss_currentRelation, PlanState::state, ParallelContext::toc, and IndexScanDescData::xs_want_itup.

Referenced by ExecParallelInitializeDSM().

644 {
645  EState *estate = node->ss.ps.state;
646  ParallelIndexScanDesc piscan;
647 
648  piscan = shm_toc_allocate(pcxt->toc, node->ioss_PscanLen);
650  node->ioss_RelationDesc,
651  estate->es_snapshot,
652  piscan);
653  shm_toc_insert(pcxt->toc, node->ss.ps.plan->plan_node_id, piscan);
654  node->ioss_ScanDesc =
656  node->ioss_RelationDesc,
657  node->ioss_NumScanKeys,
658  node->ioss_NumOrderByKeys,
659  piscan);
660  node->ioss_ScanDesc->xs_want_itup = true;
662 
663  /*
664  * If no run-time keys to calculate or they are ready, go ahead and pass
665  * the scankeys to the index AM.
666  */
667  if (node->ioss_NumRuntimeKeys == 0 || node->ioss_RuntimeKeysReady)
669  node->ioss_ScanKeys, node->ioss_NumScanKeys,
671 }
bool ioss_RuntimeKeysReady
Definition: execnodes.h:1428
IndexScanDesc index_beginscan_parallel(Relation heaprel, Relation indexrel, int nkeys, int norderbys, ParallelIndexScanDesc pscan)
Definition: indexam.c:496
int plan_node_id
Definition: plannodes.h:131
#define InvalidBuffer
Definition: buf.h:25
void index_rescan(IndexScanDesc scan, ScanKey keys, int nkeys, ScanKey orderbys, int norderbys)
Definition: indexam.c:310
Snapshot es_snapshot
Definition: execnodes.h:372
Relation ss_currentRelation
Definition: execnodes.h:1291
EState * state
Definition: execnodes.h:1051
PlanState ps
Definition: execnodes.h:1290
ScanKey ioss_ScanKeys
Definition: execnodes.h:1422
IndexScanDesc ioss_ScanDesc
Definition: execnodes.h:1431
ScanKey ioss_OrderByKeys
Definition: execnodes.h:1424
Plan * plan
Definition: execnodes.h:1049
Relation ioss_RelationDesc
Definition: execnodes.h:1430
bool xs_want_itup
Definition: relscan.h:95
void * shm_toc_allocate(shm_toc *toc, Size nbytes)
Definition: shm_toc.c:83
void shm_toc_insert(shm_toc *toc, uint64 key, void *address)
Definition: shm_toc.c:161
void index_parallelscan_initialize(Relation heapRelation, Relation indexRelation, Snapshot snapshot, ParallelIndexScanDesc target)
Definition: indexam.c:450
shm_toc * toc
Definition: parallel.h:45
void ExecIndexOnlyScanInitializeWorker ( IndexOnlyScanState node,
shm_toc toc 
)

Definition at line 680 of file nodeIndexonlyscan.c.

References index_beginscan_parallel(), index_rescan(), IndexOnlyScanState::ioss_NumOrderByKeys, IndexOnlyScanState::ioss_NumRuntimeKeys, IndexOnlyScanState::ioss_NumScanKeys, IndexOnlyScanState::ioss_OrderByKeys, IndexOnlyScanState::ioss_RelationDesc, IndexOnlyScanState::ioss_RuntimeKeysReady, IndexOnlyScanState::ioss_ScanDesc, IndexOnlyScanState::ioss_ScanKeys, PlanState::plan, Plan::plan_node_id, ScanState::ps, shm_toc_lookup(), IndexOnlyScanState::ss, ScanState::ss_currentRelation, and IndexScanDescData::xs_want_itup.

Referenced by ExecParallelInitializeWorker().

681 {
682  ParallelIndexScanDesc piscan;
683 
684  piscan = shm_toc_lookup(toc, node->ss.ps.plan->plan_node_id);
685  node->ioss_ScanDesc =
687  node->ioss_RelationDesc,
688  node->ioss_NumScanKeys,
689  node->ioss_NumOrderByKeys,
690  piscan);
691  node->ioss_ScanDesc->xs_want_itup = true;
692 
693  /*
694  * If no run-time keys to calculate or they are ready, go ahead and pass
695  * the scankeys to the index AM.
696  */
697  if (node->ioss_NumRuntimeKeys == 0 || node->ioss_RuntimeKeysReady)
699  node->ioss_ScanKeys, node->ioss_NumScanKeys,
701 }
bool ioss_RuntimeKeysReady
Definition: execnodes.h:1428
IndexScanDesc index_beginscan_parallel(Relation heaprel, Relation indexrel, int nkeys, int norderbys, ParallelIndexScanDesc pscan)
Definition: indexam.c:496
int plan_node_id
Definition: plannodes.h:131
void index_rescan(IndexScanDesc scan, ScanKey keys, int nkeys, ScanKey orderbys, int norderbys)
Definition: indexam.c:310
Relation ss_currentRelation
Definition: execnodes.h:1291
PlanState ps
Definition: execnodes.h:1290
ScanKey ioss_ScanKeys
Definition: execnodes.h:1422
void * shm_toc_lookup(shm_toc *toc, uint64 key)
Definition: shm_toc.c:218
IndexScanDesc ioss_ScanDesc
Definition: execnodes.h:1431
ScanKey ioss_OrderByKeys
Definition: execnodes.h:1424
Plan * plan
Definition: execnodes.h:1049
Relation ioss_RelationDesc
Definition: execnodes.h:1430
bool xs_want_itup
Definition: relscan.h:95
IndexOnlyScanState* ExecInitIndexOnlyScan ( IndexOnlyScan node,
EState estate,
int  eflags 
)

Definition at line 463 of file nodeIndexonlyscan.c.

References AccessShareLock, EXEC_FLAG_EXPLAIN_ONLY, ExecAssignExprContext(), ExecAssignResultTypeFromTL(), ExecAssignScanProjectionInfoWithVarno(), ExecAssignScanType(), ExecIndexBuildScanKeys(), ExecInitExpr(), ExecInitResultTupleSlot(), ExecInitScanTupleSlot(), ExecOpenScanRelation(), ExecRelationIsTargetRelation(), ExecTypeFromTL(), index_open(), INDEX_VAR, IndexOnlyScan::indexid, IndexOnlyScan::indexorderby, IndexOnlyScan::indexqual, IndexOnlyScanState::indexqual, IndexOnlyScan::indextlist, IndexOnlyScanState::ioss_HeapFetches, IndexOnlyScanState::ioss_NumOrderByKeys, IndexOnlyScanState::ioss_NumRuntimeKeys, IndexOnlyScanState::ioss_NumScanKeys, IndexOnlyScanState::ioss_OrderByKeys, IndexOnlyScanState::ioss_RelationDesc, IndexOnlyScanState::ioss_RuntimeContext, IndexOnlyScanState::ioss_RuntimeKeys, IndexOnlyScanState::ioss_RuntimeKeysReady, IndexOnlyScanState::ioss_ScanKeys, makeNode, NoLock, NULL, Scan::plan, PlanState::plan, ScanState::ps, PlanState::ps_ExprContext, Plan::qual, PlanState::qual, IndexOnlyScan::scan, Scan::scanrelid, IndexOnlyScanState::ss, ScanState::ss_currentRelation, ScanState::ss_currentScanDesc, PlanState::state, Plan::targetlist, and PlanState::targetlist.

Referenced by ExecInitNode().

464 {
465  IndexOnlyScanState *indexstate;
466  Relation currentRelation;
467  bool relistarget;
468  TupleDesc tupDesc;
469 
470  /*
471  * create state structure
472  */
473  indexstate = makeNode(IndexOnlyScanState);
474  indexstate->ss.ps.plan = (Plan *) node;
475  indexstate->ss.ps.state = estate;
476  indexstate->ioss_HeapFetches = 0;
477 
478  /*
479  * Miscellaneous initialization
480  *
481  * create expression context for node
482  */
483  ExecAssignExprContext(estate, &indexstate->ss.ps);
484 
485  /*
486  * initialize child expressions
487  *
488  * Note: we don't initialize all of the indexorderby expression, only the
489  * sub-parts corresponding to runtime keys (see below).
490  */
491  indexstate->ss.ps.targetlist = (List *)
493  (PlanState *) indexstate);
494  indexstate->ss.ps.qual = (List *)
495  ExecInitExpr((Expr *) node->scan.plan.qual,
496  (PlanState *) indexstate);
497  indexstate->indexqual = (List *)
498  ExecInitExpr((Expr *) node->indexqual,
499  (PlanState *) indexstate);
500 
501  /*
502  * tuple table initialization
503  */
504  ExecInitResultTupleSlot(estate, &indexstate->ss.ps);
505  ExecInitScanTupleSlot(estate, &indexstate->ss);
506 
507  /*
508  * open the base relation and acquire appropriate lock on it.
509  */
510  currentRelation = ExecOpenScanRelation(estate, node->scan.scanrelid, eflags);
511 
512  indexstate->ss.ss_currentRelation = currentRelation;
513  indexstate->ss.ss_currentScanDesc = NULL; /* no heap scan here */
514 
515  /*
516  * Build the scan tuple type using the indextlist generated by the
517  * planner. We use this, rather than the index's physical tuple
518  * descriptor, because the latter contains storage column types not the
519  * types of the original datums. (It's the AM's responsibility to return
520  * suitable data anyway.)
521  */
522  tupDesc = ExecTypeFromTL(node->indextlist, false);
523  ExecAssignScanType(&indexstate->ss, tupDesc);
524 
525  /*
526  * Initialize result tuple type and projection info. The node's
527  * targetlist will contain Vars with varno = INDEX_VAR, referencing the
528  * scan tuple.
529  */
530  ExecAssignResultTypeFromTL(&indexstate->ss.ps);
532 
533  /*
534  * If we are just doing EXPLAIN (ie, aren't going to run the plan), stop
535  * here. This allows an index-advisor plugin to EXPLAIN a plan containing
536  * references to nonexistent indexes.
537  */
538  if (eflags & EXEC_FLAG_EXPLAIN_ONLY)
539  return indexstate;
540 
541  /*
542  * Open the index relation.
543  *
544  * If the parent table is one of the target relations of the query, then
545  * InitPlan already opened and write-locked the index, so we can avoid
546  * taking another lock here. Otherwise we need a normal reader's lock.
547  */
548  relistarget = ExecRelationIsTargetRelation(estate, node->scan.scanrelid);
549  indexstate->ioss_RelationDesc = index_open(node->indexid,
550  relistarget ? NoLock : AccessShareLock);
551 
552  /*
553  * Initialize index-specific scan state
554  */
555  indexstate->ioss_RuntimeKeysReady = false;
556  indexstate->ioss_RuntimeKeys = NULL;
557  indexstate->ioss_NumRuntimeKeys = 0;
558 
559  /*
560  * build the index scan keys from the index qualification
561  */
562  ExecIndexBuildScanKeys((PlanState *) indexstate,
563  indexstate->ioss_RelationDesc,
564  node->indexqual,
565  false,
566  &indexstate->ioss_ScanKeys,
567  &indexstate->ioss_NumScanKeys,
568  &indexstate->ioss_RuntimeKeys,
569  &indexstate->ioss_NumRuntimeKeys,
570  NULL, /* no ArrayKeys */
571  NULL);
572 
573  /*
574  * any ORDER BY exprs have to be turned into scankeys in the same way
575  */
576  ExecIndexBuildScanKeys((PlanState *) indexstate,
577  indexstate->ioss_RelationDesc,
578  node->indexorderby,
579  true,
580  &indexstate->ioss_OrderByKeys,
581  &indexstate->ioss_NumOrderByKeys,
582  &indexstate->ioss_RuntimeKeys,
583  &indexstate->ioss_NumRuntimeKeys,
584  NULL, /* no ArrayKeys */
585  NULL);
586 
587  /*
588  * If we have runtime keys, we need an ExprContext to evaluate them. The
589  * node's standard context won't do because we want to reset that context
590  * for every tuple. So, build another context just like the other one...
591  * -tgl 7/11/00
592  */
593  if (indexstate->ioss_NumRuntimeKeys != 0)
594  {
595  ExprContext *stdecontext = indexstate->ss.ps.ps_ExprContext;
596 
597  ExecAssignExprContext(estate, &indexstate->ss.ps);
598  indexstate->ioss_RuntimeContext = indexstate->ss.ps.ps_ExprContext;
599  indexstate->ss.ps.ps_ExprContext = stdecontext;
600  }
601  else
602  {
603  indexstate->ioss_RuntimeContext = NULL;
604  }
605 
606  /*
607  * all done.
608  */
609  return indexstate;
610 }
bool ioss_RuntimeKeysReady
Definition: execnodes.h:1428
List * qual
Definition: plannodes.h:133
Plan plan
Definition: plannodes.h:315
void ExecInitScanTupleSlot(EState *estate, ScanState *scanstate)
Definition: execTuples.c:842
Index scanrelid
Definition: plannodes.h:316
ExprContext * ps_ExprContext
Definition: execnodes.h:1080
#define AccessShareLock
Definition: lockdefs.h:36
List * qual
Definition: execnodes.h:1064
IndexRuntimeKeyInfo * ioss_RuntimeKeys
Definition: execnodes.h:1426
List * targetlist
Definition: execnodes.h:1063
Relation ss_currentRelation
Definition: execnodes.h:1291
EState * state
Definition: execnodes.h:1051
void ExecAssignResultTypeFromTL(PlanState *planstate)
Definition: execUtils.c:431
void ExecAssignScanProjectionInfoWithVarno(ScanState *node, Index varno)
Definition: execScan.c:247
PlanState ps
Definition: execnodes.h:1290
ScanKey ioss_ScanKeys
Definition: execnodes.h:1422
ExprState * ExecInitExpr(Expr *node, PlanState *parent)
Definition: execQual.c:4267
void ExecInitResultTupleSlot(EState *estate, PlanState *planstate)
Definition: execTuples.c:832
Relation ExecOpenScanRelation(EState *estate, Index scanrelid, int eflags)
Definition: execUtils.c:773
ExprContext * ioss_RuntimeContext
Definition: execnodes.h:1429
#define NoLock
Definition: lockdefs.h:34
ScanKey ioss_OrderByKeys
Definition: execnodes.h:1424
TupleDesc ExecTypeFromTL(List *targetList, bool hasoid)
Definition: execTuples.c:888
Plan * plan
Definition: execnodes.h:1049
Relation ioss_RelationDesc
Definition: execnodes.h:1430
List * indextlist
Definition: plannodes.h:408
List * indexorderby
Definition: plannodes.h:407
#define makeNode(_type_)
Definition: nodes.h:570
#define NULL
Definition: c.h:229
void ExecAssignExprContext(EState *estate, PlanState *planstate)
Definition: execUtils.c:409
void ExecIndexBuildScanKeys(PlanState *planstate, Relation index, List *quals, bool isorderby, ScanKey *scanKeys, int *numScanKeys, IndexRuntimeKeyInfo **runtimeKeys, int *numRuntimeKeys, IndexArrayKeyInfo **arrayKeys, int *numArrayKeys)
List * indexqual
Definition: plannodes.h:406
List * targetlist
Definition: plannodes.h:132
HeapScanDesc ss_currentScanDesc
Definition: execnodes.h:1292
void ExecAssignScanType(ScanState *scanstate, TupleDesc tupDesc)
Definition: execUtils.c:710
#define INDEX_VAR
Definition: primnodes.h:155
Definition: pg_list.h:45
#define EXEC_FLAG_EXPLAIN_ONLY
Definition: executor.h:58
Relation index_open(Oid relationId, LOCKMODE lockmode)
Definition: indexam.c:151
bool ExecRelationIsTargetRelation(EState *estate, Index scanrelid)
Definition: execUtils.c:747
void ExecReScanIndexOnlyScan ( IndexOnlyScanState node)

Definition at line 332 of file nodeIndexonlyscan.c.

References ExecIndexEvalRuntimeKeys(), ExecScanReScan(), index_parallelrescan(), index_rescan(), IndexOnlyScanState::ioss_NumOrderByKeys, IndexOnlyScanState::ioss_NumRuntimeKeys, IndexOnlyScanState::ioss_NumScanKeys, IndexOnlyScanState::ioss_OrderByKeys, IndexOnlyScanState::ioss_RuntimeContext, IndexOnlyScanState::ioss_RuntimeKeys, IndexOnlyScanState::ioss_RuntimeKeysReady, IndexOnlyScanState::ioss_ScanDesc, IndexOnlyScanState::ioss_ScanKeys, IndexScanDescData::parallel_scan, ResetExprContext, and IndexOnlyScanState::ss.

Referenced by ExecReScan().

333 {
334  bool reset_parallel_scan = true;
335 
336  /*
337  * If we are here to just update the scan keys, then don't reset parallel
338  * scan. For detailed reason behind this look in the comments for
339  * ExecReScanIndexScan.
340  */
341  if (node->ioss_NumRuntimeKeys != 0 && !node->ioss_RuntimeKeysReady)
342  reset_parallel_scan = false;
343 
344  /*
345  * If we are doing runtime key calculations (ie, any of the index key
346  * values weren't simple Consts), compute the new key values. But first,
347  * reset the context so we don't leak memory as each outer tuple is
348  * scanned. Note this assumes that we will recalculate *all* runtime keys
349  * on each call.
350  */
351  if (node->ioss_NumRuntimeKeys != 0)
352  {
353  ExprContext *econtext = node->ioss_RuntimeContext;
354 
355  ResetExprContext(econtext);
356  ExecIndexEvalRuntimeKeys(econtext,
357  node->ioss_RuntimeKeys,
358  node->ioss_NumRuntimeKeys);
359  }
360  node->ioss_RuntimeKeysReady = true;
361 
362  /* reset index scan */
363  if (node->ioss_ScanDesc)
364  {
365 
367  node->ioss_ScanKeys, node->ioss_NumScanKeys,
369 
370  if (reset_parallel_scan && node->ioss_ScanDesc->parallel_scan)
372  }
373  ExecScanReScan(&node->ss);
374 }
bool ioss_RuntimeKeysReady
Definition: execnodes.h:1428
ParallelIndexScanDesc parallel_scan
Definition: relscan.h:139
void index_rescan(IndexScanDesc scan, ScanKey keys, int nkeys, ScanKey orderbys, int norderbys)
Definition: indexam.c:310
IndexRuntimeKeyInfo * ioss_RuntimeKeys
Definition: execnodes.h:1426
void index_parallelrescan(IndexScanDesc scan)
Definition: indexam.c:481
ScanKey ioss_ScanKeys
Definition: execnodes.h:1422
ExprContext * ioss_RuntimeContext
Definition: execnodes.h:1429
IndexScanDesc ioss_ScanDesc
Definition: execnodes.h:1431
ScanKey ioss_OrderByKeys
Definition: execnodes.h:1424
void ExecIndexEvalRuntimeKeys(ExprContext *econtext, IndexRuntimeKeyInfo *runtimeKeys, int numRuntimeKeys)
void ExecScanReScan(ScanState *node)
Definition: execScan.c:327
#define ResetExprContext(econtext)
Definition: executor.h:333
static TupleTableSlot * IndexOnlyNext ( IndexOnlyScanState node)
static

Definition at line 55 of file nodeIndexonlyscan.c.

References Assert, BackwardScanDirection, ExprContext::ecxt_scantuple, elog, ereport, errcode(), errmsg(), ERROR, EState::es_direction, EState::es_snapshot, ExecClearTuple(), ExecQual(), ExecStoreTuple(), ForwardScanDirection, IndexScanDescData::heapRelation, index_beginscan(), index_fetch_heap(), index_getnext_tid(), index_rescan(), IndexOnlyScanState::indexqual, InstrCountFiltered2, InvalidBuffer, IndexOnlyScanState::ioss_HeapFetches, IndexOnlyScanState::ioss_NumOrderByKeys, IndexOnlyScanState::ioss_NumRuntimeKeys, IndexOnlyScanState::ioss_NumScanKeys, IndexOnlyScanState::ioss_OrderByKeys, IndexOnlyScanState::ioss_RelationDesc, IndexOnlyScanState::ioss_RuntimeKeysReady, IndexOnlyScanState::ioss_ScanDesc, IndexOnlyScanState::ioss_ScanKeys, IndexOnlyScanState::ioss_VMBuffer, ItemPointerGetBlockNumber, tupleDesc::natts, NULL, IndexScanDescData::numberOfOrderBys, PlanState::plan, PredicateLockPage(), ScanState::ps, PlanState::ps_ExprContext, ResetExprContext, ScanDirectionIsBackward, ScanDirectionIsForward, IndexOnlyScanState::ss, ScanState::ss_currentRelation, ScanState::ss_ScanTupleSlot, PlanState::state, StoreIndexTuple(), TupleTableSlot::tts_tupleDescriptor, VM_ALL_VISIBLE, IndexScanDescData::xs_continue_hot, IndexScanDescData::xs_hitup, IndexScanDescData::xs_hitupdesc, IndexScanDescData::xs_itup, IndexScanDescData::xs_itupdesc, IndexScanDescData::xs_recheck, IndexScanDescData::xs_recheckorderby, and IndexScanDescData::xs_want_itup.

Referenced by ExecIndexOnlyScan().

56 {
57  EState *estate;
58  ExprContext *econtext;
59  ScanDirection direction;
60  IndexScanDesc scandesc;
61  TupleTableSlot *slot;
62  ItemPointer tid;
63 
64  /*
65  * extract necessary information from index scan node
66  */
67  estate = node->ss.ps.state;
68  direction = estate->es_direction;
69  /* flip direction if this is an overall backward scan */
70  if (ScanDirectionIsBackward(((IndexOnlyScan *) node->ss.ps.plan)->indexorderdir))
71  {
72  if (ScanDirectionIsForward(direction))
73  direction = BackwardScanDirection;
74  else if (ScanDirectionIsBackward(direction))
75  direction = ForwardScanDirection;
76  }
77  scandesc = node->ioss_ScanDesc;
78  econtext = node->ss.ps.ps_ExprContext;
79  slot = node->ss.ss_ScanTupleSlot;
80 
81  if (scandesc == NULL)
82  {
83  /*
84  * We reach here if the index only scan is not parallel, or if we're
85  * executing a index only scan that was intended to be parallel
86  * serially.
87  */
88  scandesc = index_beginscan(node->ss.ss_currentRelation,
89  node->ioss_RelationDesc,
90  estate->es_snapshot,
91  node->ioss_NumScanKeys,
92  node->ioss_NumOrderByKeys);
93 
94  node->ioss_ScanDesc = scandesc;
95 
96 
97  /* Set it up for index-only scan */
98  node->ioss_ScanDesc->xs_want_itup = true;
100 
101  /*
102  * If no run-time keys to calculate or they are ready, go ahead and
103  * pass the scankeys to the index AM.
104  */
105  if (node->ioss_NumRuntimeKeys == 0 || node->ioss_RuntimeKeysReady)
106  index_rescan(scandesc,
107  node->ioss_ScanKeys,
108  node->ioss_NumScanKeys,
109  node->ioss_OrderByKeys,
110  node->ioss_NumOrderByKeys);
111  }
112 
113  /*
114  * OK, now that we have what we need, fetch the next tuple.
115  */
116  while ((tid = index_getnext_tid(scandesc, direction)) != NULL)
117  {
118  HeapTuple tuple = NULL;
119 
120  /*
121  * We can skip the heap fetch if the TID references a heap page on
122  * which all tuples are known visible to everybody. In any case,
123  * we'll use the index tuple not the heap tuple as the data source.
124  *
125  * Note on Memory Ordering Effects: visibilitymap_get_status does not
126  * lock the visibility map buffer, and therefore the result we read
127  * here could be slightly stale. However, it can't be stale enough to
128  * matter.
129  *
130  * We need to detect clearing a VM bit due to an insert right away,
131  * because the tuple is present in the index page but not visible. The
132  * reading of the TID by this scan (using a shared lock on the index
133  * buffer) is serialized with the insert of the TID into the index
134  * (using an exclusive lock on the index buffer). Because the VM bit
135  * is cleared before updating the index, and locking/unlocking of the
136  * index page acts as a full memory barrier, we are sure to see the
137  * cleared bit if we see a recently-inserted TID.
138  *
139  * Deletes do not update the index page (only VACUUM will clear out
140  * the TID), so the clearing of the VM bit by a delete is not
141  * serialized with this test below, and we may see a value that is
142  * significantly stale. However, we don't care about the delete right
143  * away, because the tuple is still visible until the deleting
144  * transaction commits or the statement ends (if it's our
145  * transaction). In either case, the lock on the VM buffer will have
146  * been released (acting as a write barrier) after clearing the bit.
147  * And for us to have a snapshot that includes the deleting
148  * transaction (making the tuple invisible), we must have acquired
149  * ProcArrayLock after that time, acting as a read barrier.
150  *
151  * It's worth going through this complexity to avoid needing to lock
152  * the VM buffer, which could cause significant contention.
153  */
154  if (!VM_ALL_VISIBLE(scandesc->heapRelation,
156  &node->ioss_VMBuffer))
157  {
158  /*
159  * Rats, we have to visit the heap to check visibility.
160  */
161  node->ioss_HeapFetches++;
162  tuple = index_fetch_heap(scandesc);
163  if (tuple == NULL)
164  continue; /* no visible tuple, try next index entry */
165 
166  /*
167  * Only MVCC snapshots are supported here, so there should be no
168  * need to keep following the HOT chain once a visible entry has
169  * been found. If we did want to allow that, we'd need to keep
170  * more state to remember not to call index_getnext_tid next time.
171  */
172  if (scandesc->xs_continue_hot)
173  elog(ERROR, "non-MVCC snapshots are not supported in index-only scans");
174 
175  /*
176  * Note: at this point we are holding a pin on the heap page, as
177  * recorded in scandesc->xs_cbuf. We could release that pin now,
178  * but it's not clear whether it's a win to do so. The next index
179  * entry might require a visit to the same heap page.
180  */
181  }
182 
183  /*
184  * Fill the scan tuple slot with data from the index. This might be
185  * provided in either HeapTuple or IndexTuple format. Conceivably an
186  * index AM might fill both fields, in which case we prefer the heap
187  * format, since it's probably a bit cheaper to fill a slot from.
188  */
189  if (scandesc->xs_hitup)
190  {
191  /*
192  * We don't take the trouble to verify that the provided tuple has
193  * exactly the slot's format, but it seems worth doing a quick
194  * check on the number of fields.
195  */
197  scandesc->xs_hitupdesc->natts);
198  ExecStoreTuple(scandesc->xs_hitup, slot, InvalidBuffer, false);
199  }
200  else if (scandesc->xs_itup)
201  StoreIndexTuple(slot, scandesc->xs_itup, scandesc->xs_itupdesc);
202  else
203  elog(ERROR, "no data returned for index-only scan");
204 
205  /*
206  * If the index was lossy, we have to recheck the index quals.
207  * (Currently, this can never happen, but we should support the case
208  * for possible future use, eg with GiST indexes.)
209  */
210  if (scandesc->xs_recheck)
211  {
212  econtext->ecxt_scantuple = slot;
213  ResetExprContext(econtext);
214  if (!ExecQual(node->indexqual, econtext, false))
215  {
216  /* Fails recheck, so drop it and loop back for another */
217  InstrCountFiltered2(node, 1);
218  continue;
219  }
220  }
221 
222  /*
223  * We don't currently support rechecking ORDER BY distances. (In
224  * principle, if the index can support retrieval of the originally
225  * indexed value, it should be able to produce an exact distance
226  * calculation too. So it's not clear that adding code here for
227  * recheck/re-sort would be worth the trouble. But we should at least
228  * throw an error if someone tries it.)
229  */
230  if (scandesc->numberOfOrderBys > 0 && scandesc->xs_recheckorderby)
231  ereport(ERROR,
232  (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
233  errmsg("lossy distance functions are not supported in index-only scans")));
234 
235  /*
236  * Predicate locks for index-only scans must be acquired at the page
237  * level when the heap is not accessed, since tuple-level predicate
238  * locks need the tuple's xmin value. If we had to visit the tuple
239  * anyway, then we already have the tuple-level lock and can skip the
240  * page lock.
241  */
242  if (tuple == NULL)
245  estate->es_snapshot);
246 
247  return slot;
248  }
249 
250  /*
251  * if we get here it means the index scan failed so we are at the end of
252  * the scan..
253  */
254  return ExecClearTuple(slot);
255 }
bool ioss_RuntimeKeysReady
Definition: execnodes.h:1428
TupleTableSlot * ExecStoreTuple(HeapTuple tuple, TupleTableSlot *slot, Buffer buffer, bool shouldFree)
Definition: execTuples.c:320
void PredicateLockPage(Relation relation, BlockNumber blkno, Snapshot snapshot)
Definition: predicate.c:2438
#define ScanDirectionIsForward(direction)
Definition: sdir.h:55
IndexTuple xs_itup
Definition: relscan.h:113
ExprContext * ps_ExprContext
Definition: execnodes.h:1080
TupleTableSlot * ExecClearTuple(TupleTableSlot *slot)
Definition: execTuples.c:439
#define InvalidBuffer
Definition: buf.h:25
void index_rescan(IndexScanDesc scan, ScanKey keys, int nkeys, ScanKey orderbys, int norderbys)
Definition: indexam.c:310
int errcode(int sqlerrcode)
Definition: elog.c:575
bool xs_recheckorderby
Definition: relscan.h:133
Snapshot es_snapshot
Definition: execnodes.h:372
TupleTableSlot * ss_ScanTupleSlot
Definition: execnodes.h:1293
TupleDesc xs_itupdesc
Definition: relscan.h:114
Relation ss_currentRelation
Definition: execnodes.h:1291
EState * state
Definition: execnodes.h:1051
int natts
Definition: tupdesc.h:73
TupleDesc xs_hitupdesc
Definition: relscan.h:116
ScanDirection es_direction
Definition: execnodes.h:371
Relation heapRelation
Definition: relscan.h:88
PlanState ps
Definition: execnodes.h:1290
ScanKey ioss_ScanKeys
Definition: execnodes.h:1422
#define ScanDirectionIsBackward(direction)
Definition: sdir.h:41
ItemPointer index_getnext_tid(IndexScanDesc scan, ScanDirection direction)
Definition: indexam.c:526
#define ERROR
Definition: elog.h:43
HeapTuple index_fetch_heap(IndexScanDesc scan)
Definition: indexam.c:583
IndexScanDesc ioss_ScanDesc
Definition: execnodes.h:1431
ScanDirection
Definition: sdir.h:22
bool xs_continue_hot
Definition: relscan.h:136
bool ExecQual(List *qual, ExprContext *econtext, bool resultForNull)
Definition: execQual.c:5056
#define ereport(elevel, rest)
Definition: elog.h:122
ScanKey ioss_OrderByKeys
Definition: execnodes.h:1424
TupleDesc tts_tupleDescriptor
Definition: tuptable.h:121
Plan * plan
Definition: execnodes.h:1049
Relation ioss_RelationDesc
Definition: execnodes.h:1430
bool xs_want_itup
Definition: relscan.h:95
#define NULL
Definition: c.h:229
#define Assert(condition)
Definition: c.h:675
static void StoreIndexTuple(TupleTableSlot *slot, IndexTuple itup, TupleDesc itupdesc)
#define InstrCountFiltered2(node, delta)
Definition: execnodes.h:1100
#define VM_ALL_VISIBLE(r, b, v)
Definition: visibilitymap.h:32
TupleTableSlot * ecxt_scantuple
Definition: execnodes.h:130
int errmsg(const char *fmt,...)
Definition: elog.c:797
HeapTuple xs_hitup
Definition: relscan.h:115
int numberOfOrderBys
Definition: relscan.h:92
#define elog
Definition: elog.h:219
#define ItemPointerGetBlockNumber(pointer)
Definition: itemptr.h:66
#define ResetExprContext(econtext)
Definition: executor.h:333
IndexScanDesc index_beginscan(Relation heapRelation, Relation indexRelation, Snapshot snapshot, int nkeys, int norderbys)
Definition: indexam.c:221
static bool IndexOnlyRecheck ( IndexOnlyScanState node,
TupleTableSlot slot 
)
static

Definition at line 296 of file nodeIndexonlyscan.c.

References elog, and ERROR.

Referenced by ExecIndexOnlyScan().

297 {
298  elog(ERROR, "EvalPlanQual recheck is not supported in index-only scans");
299  return false; /* keep compiler quiet */
300 }
#define ERROR
Definition: elog.h:43
#define elog
Definition: elog.h:219
static void StoreIndexTuple ( TupleTableSlot slot,
IndexTuple  itup,
TupleDesc  itupdesc 
)
static

Definition at line 265 of file nodeIndexonlyscan.c.

References Assert, ExecClearTuple(), ExecStoreVirtualTuple(), i, index_getattr, tupleDesc::natts, TupleTableSlot::tts_isnull, TupleTableSlot::tts_tupleDescriptor, TupleTableSlot::tts_values, and values.

Referenced by IndexOnlyNext().

266 {
267  int nindexatts = itupdesc->natts;
268  Datum *values = slot->tts_values;
269  bool *isnull = slot->tts_isnull;
270  int i;
271 
272  /*
273  * Note: we must use the tupdesc supplied by the AM in index_getattr, not
274  * the slot's tupdesc, in case the latter has different datatypes (this
275  * happens for btree name_ops in particular). They'd better have the same
276  * number of columns though, as well as being datatype-compatible which is
277  * something we can't so easily check.
278  */
279  Assert(slot->tts_tupleDescriptor->natts == nindexatts);
280 
281  ExecClearTuple(slot);
282  for (i = 0; i < nindexatts; i++)
283  values[i] = index_getattr(itup, i + 1, itupdesc, &isnull[i]);
284  ExecStoreVirtualTuple(slot);
285 }
TupleTableSlot * ExecClearTuple(TupleTableSlot *slot)
Definition: execTuples.c:439
Datum * tts_values
Definition: tuptable.h:125
int natts
Definition: tupdesc.h:73
bool * tts_isnull
Definition: tuptable.h:126
TupleDesc tts_tupleDescriptor
Definition: tuptable.h:121
uintptr_t Datum
Definition: postgres.h:372
#define Assert(condition)
Definition: c.h:675
#define index_getattr(tup, attnum, tupleDesc, isnull)
Definition: itup.h:100
static Datum values[MAXATTR]
Definition: bootstrap.c:162
int i
TupleTableSlot * ExecStoreVirtualTuple(TupleTableSlot *slot)
Definition: execTuples.c:488