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nodeIndexonlyscan.c File Reference
#include "postgres.h"
#include "access/relscan.h"
#include "access/visibilitymap.h"
#include "executor/execdebug.h"
#include "executor/nodeIndexonlyscan.h"
#include "executor/nodeIndexscan.h"
#include "miscadmin.h"
#include "storage/bufmgr.h"
#include "storage/predicate.h"
#include "utils/memutils.h"
#include "utils/rel.h"
Include dependency graph for nodeIndexonlyscan.c:

Go to the source code of this file.

Functions

static TupleTableSlotIndexOnlyNext (IndexOnlyScanState *node)
 
static void StoreIndexTuple (TupleTableSlot *slot, IndexTuple itup, TupleDesc itupdesc)
 
static bool IndexOnlyRecheck (IndexOnlyScanState *node, TupleTableSlot *slot)
 
static TupleTableSlotExecIndexOnlyScan (PlanState *pstate)
 
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 387 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().

388 {
389  Relation indexRelationDesc;
390  IndexScanDesc indexScanDesc;
391  Relation relation;
392 
393  /*
394  * extract information from the node
395  */
396  indexRelationDesc = node->ioss_RelationDesc;
397  indexScanDesc = node->ioss_ScanDesc;
398  relation = node->ss.ss_currentRelation;
399 
400  /* Release VM buffer pin, if any. */
401  if (node->ioss_VMBuffer != InvalidBuffer)
402  {
405  }
406 
407  /*
408  * Free the exprcontext(s) ... now dead code, see ExecFreeExprContext
409  */
410 #ifdef NOT_USED
411  ExecFreeExprContext(&node->ss.ps);
412  if (node->ioss_RuntimeContext)
414 #endif
415 
416  /*
417  * clear out tuple table slots
418  */
421 
422  /*
423  * close the index relation (no-op if we didn't open it)
424  */
425  if (indexScanDesc)
426  index_endscan(indexScanDesc);
427  if (indexRelationDesc)
428  index_close(indexRelationDesc, NoLock);
429 
430  /*
431  * close the heap relation.
432  */
433  ExecCloseScanRelation(relation);
434 }
TupleTableSlot * ExecClearTuple(TupleTableSlot *slot)
Definition: execTuples.c:439
#define InvalidBuffer
Definition: buf.h:25
TupleTableSlot * ss_ScanTupleSlot
Definition: execnodes.h:1101
void ReleaseBuffer(Buffer buffer)
Definition: bufmgr.c:3309
Relation ss_currentRelation
Definition: execnodes.h:1099
void ExecFreeExprContext(PlanState *planstate)
Definition: execUtils.c:521
PlanState ps
Definition: execnodes.h:1098
TupleTableSlot * ps_ResultTupleSlot
Definition: execnodes.h:880
ExprContext * ioss_RuntimeContext
Definition: execnodes.h:1237
#define NoLock
Definition: lockdefs.h:34
IndexScanDesc ioss_ScanDesc
Definition: execnodes.h:1239
void index_endscan(IndexScanDesc scan)
Definition: indexam.c:340
void FreeExprContext(ExprContext *econtext, bool isCommit)
Definition: execUtils.c:354
Relation ioss_RelationDesc
Definition: execnodes.h:1238
void ExecCloseScanRelation(Relation scanrel)
Definition: execUtils.c:666
void index_close(Relation relation, LOCKMODE lockmode)
Definition: indexam.c:176
void ExecIndexOnlyMarkPos ( IndexOnlyScanState node)

Definition at line 441 of file nodeIndexonlyscan.c.

References index_markpos(), and IndexOnlyScanState::ioss_ScanDesc.

Referenced by ExecMarkPos().

442 {
444 }
void index_markpos(IndexScanDesc scan)
Definition: indexam.c:370
IndexScanDesc ioss_ScanDesc
Definition: execnodes.h:1239
void ExecIndexOnlyRestrPos ( IndexOnlyScanState node)

Definition at line 451 of file nodeIndexonlyscan.c.

References index_restrpos(), and IndexOnlyScanState::ioss_ScanDesc.

Referenced by ExecRestrPos().

452 {
454 }
void index_restrpos(IndexScanDesc scan)
Definition: indexam.c:395
IndexScanDesc ioss_ScanDesc
Definition: execnodes.h:1239
static TupleTableSlot* ExecIndexOnlyScan ( PlanState pstate)
static

Definition at line 310 of file nodeIndexonlyscan.c.

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

Referenced by ExecInitIndexOnlyScan().

311 {
313 
314  /*
315  * If we have runtime keys and they've not already been set up, do it now.
316  */
317  if (node->ioss_NumRuntimeKeys != 0 && !node->ioss_RuntimeKeysReady)
318  ExecReScan((PlanState *) node);
319 
320  return ExecScan(&node->ss,
323 }
bool ioss_RuntimeKeysReady
Definition: execnodes.h:1236
#define castNode(_type_, nodeptr)
Definition: nodes.h:578
TupleTableSlot * ExecScan(ScanState *node, ExecScanAccessMtd accessMtd, ExecScanRecheckMtd recheckMtd)
Definition: execScan.c:121
void ExecReScan(PlanState *node)
Definition: execAmi.c:76
static bool IndexOnlyRecheck(IndexOnlyScanState *node, TupleTableSlot *slot)
TupleTableSlot *(* ExecScanAccessMtd)(ScanState *node)
Definition: executor.h:408
bool(* ExecScanRecheckMtd)(ScanState *node, TupleTableSlot *slot)
Definition: executor.h:409
static TupleTableSlot * IndexOnlyNext(IndexOnlyScanState *node)
void ExecIndexOnlyScanEstimate ( IndexOnlyScanState node,
ParallelContext pcxt 
)

Definition at line 625 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().

627 {
628  EState *estate = node->ss.ps.state;
629 
631  estate->es_snapshot);
633  shm_toc_estimate_keys(&pcxt->estimator, 1);
634 }
shm_toc_estimator estimator
Definition: parallel.h:41
Snapshot es_snapshot
Definition: execnodes.h:429
EState * state
Definition: execnodes.h:849
#define shm_toc_estimate_chunk(e, sz)
Definition: shm_toc.h:51
Size index_parallelscan_estimate(Relation indexRelation, Snapshot snapshot)
Definition: indexam.c:417
PlanState ps
Definition: execnodes.h:1098
Relation ioss_RelationDesc
Definition: execnodes.h:1238
#define shm_toc_estimate_keys(e, cnt)
Definition: shm_toc.h:53
void ExecIndexOnlyScanInitializeDSM ( IndexOnlyScanState node,
ParallelContext pcxt 
)

Definition at line 643 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().

645 {
646  EState *estate = node->ss.ps.state;
647  ParallelIndexScanDesc piscan;
648 
649  piscan = shm_toc_allocate(pcxt->toc, node->ioss_PscanLen);
651  node->ioss_RelationDesc,
652  estate->es_snapshot,
653  piscan);
654  shm_toc_insert(pcxt->toc, node->ss.ps.plan->plan_node_id, piscan);
655  node->ioss_ScanDesc =
657  node->ioss_RelationDesc,
658  node->ioss_NumScanKeys,
659  node->ioss_NumOrderByKeys,
660  piscan);
661  node->ioss_ScanDesc->xs_want_itup = true;
663 
664  /*
665  * If no run-time keys to calculate or they are ready, go ahead and pass
666  * the scankeys to the index AM.
667  */
668  if (node->ioss_NumRuntimeKeys == 0 || node->ioss_RuntimeKeysReady)
670  node->ioss_ScanKeys, node->ioss_NumScanKeys,
672 }
bool ioss_RuntimeKeysReady
Definition: execnodes.h:1236
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:143
#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:429
Relation ss_currentRelation
Definition: execnodes.h:1099
EState * state
Definition: execnodes.h:849
PlanState ps
Definition: execnodes.h:1098
ScanKey ioss_ScanKeys
Definition: execnodes.h:1230
IndexScanDesc ioss_ScanDesc
Definition: execnodes.h:1239
ScanKey ioss_OrderByKeys
Definition: execnodes.h:1232
Plan * plan
Definition: execnodes.h:847
Relation ioss_RelationDesc
Definition: execnodes.h:1238
bool xs_want_itup
Definition: relscan.h:96
void * shm_toc_allocate(shm_toc *toc, Size nbytes)
Definition: shm_toc.c:88
void shm_toc_insert(shm_toc *toc, uint64 key, void *address)
Definition: shm_toc.c:171
void index_parallelscan_initialize(Relation heapRelation, Relation indexRelation, Snapshot snapshot, ParallelIndexScanDesc target)
Definition: indexam.c:450
shm_toc * toc
Definition: parallel.h:44
void ExecIndexOnlyScanInitializeWorker ( IndexOnlyScanState node,
shm_toc toc 
)

Definition at line 681 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().

682 {
683  ParallelIndexScanDesc piscan;
684 
685  piscan = shm_toc_lookup(toc, node->ss.ps.plan->plan_node_id, false);
686  node->ioss_ScanDesc =
688  node->ioss_RelationDesc,
689  node->ioss_NumScanKeys,
690  node->ioss_NumOrderByKeys,
691  piscan);
692  node->ioss_ScanDesc->xs_want_itup = true;
693 
694  /*
695  * If no run-time keys to calculate or they are ready, go ahead and pass
696  * the scankeys to the index AM.
697  */
698  if (node->ioss_NumRuntimeKeys == 0 || node->ioss_RuntimeKeysReady)
700  node->ioss_ScanKeys, node->ioss_NumScanKeys,
702 }
bool ioss_RuntimeKeysReady
Definition: execnodes.h:1236
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:143
void index_rescan(IndexScanDesc scan, ScanKey keys, int nkeys, ScanKey orderbys, int norderbys)
Definition: indexam.c:310
Relation ss_currentRelation
Definition: execnodes.h:1099
PlanState ps
Definition: execnodes.h:1098
ScanKey ioss_ScanKeys
Definition: execnodes.h:1230
IndexScanDesc ioss_ScanDesc
Definition: execnodes.h:1239
ScanKey ioss_OrderByKeys
Definition: execnodes.h:1232
Plan * plan
Definition: execnodes.h:847
Relation ioss_RelationDesc
Definition: execnodes.h:1238
bool xs_want_itup
Definition: relscan.h:96
void * shm_toc_lookup(shm_toc *toc, uint64 key, bool noError)
Definition: shm_toc.c:232
IndexOnlyScanState* ExecInitIndexOnlyScan ( IndexOnlyScan node,
EState estate,
int  eflags 
)

Definition at line 468 of file nodeIndexonlyscan.c.

References AccessShareLock, EXEC_FLAG_EXPLAIN_ONLY, ExecAssignExprContext(), ExecAssignResultTypeFromTL(), ExecAssignScanProjectionInfoWithVarno(), ExecAssignScanType(), ExecIndexBuildScanKeys(), ExecIndexOnlyScan(), ExecInitQual(), ExecInitResultTupleSlot(), ExecInitScanTupleSlot(), ExecOpenScanRelation(), PlanState::ExecProcNode, 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, and PlanState::state.

Referenced by ExecInitNode().

469 {
470  IndexOnlyScanState *indexstate;
471  Relation currentRelation;
472  bool relistarget;
473  TupleDesc tupDesc;
474 
475  /*
476  * create state structure
477  */
478  indexstate = makeNode(IndexOnlyScanState);
479  indexstate->ss.ps.plan = (Plan *) node;
480  indexstate->ss.ps.state = estate;
481  indexstate->ss.ps.ExecProcNode = ExecIndexOnlyScan;
482  indexstate->ioss_HeapFetches = 0;
483 
484  /*
485  * Miscellaneous initialization
486  *
487  * create expression context for node
488  */
489  ExecAssignExprContext(estate, &indexstate->ss.ps);
490 
491  /*
492  * initialize child expressions
493  *
494  * Note: we don't initialize all of the indexorderby expression, only the
495  * sub-parts corresponding to runtime keys (see below).
496  */
497  indexstate->ss.ps.qual =
498  ExecInitQual(node->scan.plan.qual, (PlanState *) indexstate);
499  indexstate->indexqual =
500  ExecInitQual(node->indexqual, (PlanState *) indexstate);
501 
502  /*
503  * tuple table initialization
504  */
505  ExecInitResultTupleSlot(estate, &indexstate->ss.ps);
506  ExecInitScanTupleSlot(estate, &indexstate->ss);
507 
508  /*
509  * open the base relation and acquire appropriate lock on it.
510  */
511  currentRelation = ExecOpenScanRelation(estate, node->scan.scanrelid, eflags);
512 
513  indexstate->ss.ss_currentRelation = currentRelation;
514  indexstate->ss.ss_currentScanDesc = NULL; /* no heap scan here */
515 
516  /*
517  * Build the scan tuple type using the indextlist generated by the
518  * planner. We use this, rather than the index's physical tuple
519  * descriptor, because the latter contains storage column types not the
520  * types of the original datums. (It's the AM's responsibility to return
521  * suitable data anyway.)
522  */
523  tupDesc = ExecTypeFromTL(node->indextlist, false);
524  ExecAssignScanType(&indexstate->ss, tupDesc);
525 
526  /*
527  * Initialize result tuple type and projection info. The node's
528  * targetlist will contain Vars with varno = INDEX_VAR, referencing the
529  * scan tuple.
530  */
531  ExecAssignResultTypeFromTL(&indexstate->ss.ps);
533 
534  /*
535  * If we are just doing EXPLAIN (ie, aren't going to run the plan), stop
536  * here. This allows an index-advisor plugin to EXPLAIN a plan containing
537  * references to nonexistent indexes.
538  */
539  if (eflags & EXEC_FLAG_EXPLAIN_ONLY)
540  return indexstate;
541 
542  /*
543  * Open the index relation.
544  *
545  * If the parent table is one of the target relations of the query, then
546  * InitPlan already opened and write-locked the index, so we can avoid
547  * taking another lock here. Otherwise we need a normal reader's lock.
548  */
549  relistarget = ExecRelationIsTargetRelation(estate, node->scan.scanrelid);
550  indexstate->ioss_RelationDesc = index_open(node->indexid,
551  relistarget ? NoLock : AccessShareLock);
552 
553  /*
554  * Initialize index-specific scan state
555  */
556  indexstate->ioss_RuntimeKeysReady = false;
557  indexstate->ioss_RuntimeKeys = NULL;
558  indexstate->ioss_NumRuntimeKeys = 0;
559 
560  /*
561  * build the index scan keys from the index qualification
562  */
563  ExecIndexBuildScanKeys((PlanState *) indexstate,
564  indexstate->ioss_RelationDesc,
565  node->indexqual,
566  false,
567  &indexstate->ioss_ScanKeys,
568  &indexstate->ioss_NumScanKeys,
569  &indexstate->ioss_RuntimeKeys,
570  &indexstate->ioss_NumRuntimeKeys,
571  NULL, /* no ArrayKeys */
572  NULL);
573 
574  /*
575  * any ORDER BY exprs have to be turned into scankeys in the same way
576  */
577  ExecIndexBuildScanKeys((PlanState *) indexstate,
578  indexstate->ioss_RelationDesc,
579  node->indexorderby,
580  true,
581  &indexstate->ioss_OrderByKeys,
582  &indexstate->ioss_NumOrderByKeys,
583  &indexstate->ioss_RuntimeKeys,
584  &indexstate->ioss_NumRuntimeKeys,
585  NULL, /* no ArrayKeys */
586  NULL);
587 
588  /*
589  * If we have runtime keys, we need an ExprContext to evaluate them. The
590  * node's standard context won't do because we want to reset that context
591  * for every tuple. So, build another context just like the other one...
592  * -tgl 7/11/00
593  */
594  if (indexstate->ioss_NumRuntimeKeys != 0)
595  {
596  ExprContext *stdecontext = indexstate->ss.ps.ps_ExprContext;
597 
598  ExecAssignExprContext(estate, &indexstate->ss.ps);
599  indexstate->ioss_RuntimeContext = indexstate->ss.ps.ps_ExprContext;
600  indexstate->ss.ps.ps_ExprContext = stdecontext;
601  }
602  else
603  {
604  indexstate->ioss_RuntimeContext = NULL;
605  }
606 
607  /*
608  * all done.
609  */
610  return indexstate;
611 }
bool ioss_RuntimeKeysReady
Definition: execnodes.h:1236
List * qual
Definition: plannodes.h:145
Plan plan
Definition: plannodes.h:328
void ExecInitScanTupleSlot(EState *estate, ScanState *scanstate)
Definition: execTuples.c:842
Index scanrelid
Definition: plannodes.h:329
ExprContext * ps_ExprContext
Definition: execnodes.h:881
#define AccessShareLock
Definition: lockdefs.h:36
IndexRuntimeKeyInfo * ioss_RuntimeKeys
Definition: execnodes.h:1234
Relation ss_currentRelation
Definition: execnodes.h:1099
EState * state
Definition: execnodes.h:849
ExprState * ExecInitQual(List *qual, PlanState *parent)
Definition: execExpr.c:160
void ExecAssignResultTypeFromTL(PlanState *planstate)
Definition: execUtils.c:445
void ExecAssignScanProjectionInfoWithVarno(ScanState *node, Index varno)
Definition: execScan.c:247
PlanState ps
Definition: execnodes.h:1098
ScanKey ioss_ScanKeys
Definition: execnodes.h:1230
void ExecInitResultTupleSlot(EState *estate, PlanState *planstate)
Definition: execTuples.c:832
Relation ExecOpenScanRelation(EState *estate, Index scanrelid, int eflags)
Definition: execUtils.c:608
ExprContext * ioss_RuntimeContext
Definition: execnodes.h:1237
#define NoLock
Definition: lockdefs.h:34
ScanKey ioss_OrderByKeys
Definition: execnodes.h:1232
TupleDesc ExecTypeFromTL(List *targetList, bool hasoid)
Definition: execTuples.c:888
ExecProcNodeMtd ExecProcNode
Definition: execnodes.h:853
Plan * plan
Definition: execnodes.h:847
Relation ioss_RelationDesc
Definition: execnodes.h:1238
List * indextlist
Definition: plannodes.h:421
List * indexorderby
Definition: plannodes.h:420
#define makeNode(_type_)
Definition: nodes.h:557
#define NULL
Definition: c.h:229
static TupleTableSlot * ExecIndexOnlyScan(PlanState *pstate)
void ExecAssignExprContext(EState *estate, PlanState *planstate)
Definition: execUtils.c:423
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:419
ExprState * indexqual
Definition: execnodes.h:1229
ExprState * qual
Definition: execnodes.h:865
HeapScanDesc ss_currentScanDesc
Definition: execnodes.h:1100
void ExecAssignScanType(ScanState *scanstate, TupleDesc tupDesc)
Definition: execUtils.c:545
#define INDEX_VAR
Definition: primnodes.h:155
#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:582
void ExecReScanIndexOnlyScan ( IndexOnlyScanState node)

Definition at line 337 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().

338 {
339  bool reset_parallel_scan = true;
340 
341  /*
342  * If we are here to just update the scan keys, then don't reset parallel
343  * scan. For detailed reason behind this look in the comments for
344  * ExecReScanIndexScan.
345  */
346  if (node->ioss_NumRuntimeKeys != 0 && !node->ioss_RuntimeKeysReady)
347  reset_parallel_scan = false;
348 
349  /*
350  * If we are doing runtime key calculations (ie, any of the index key
351  * values weren't simple Consts), compute the new key values. But first,
352  * reset the context so we don't leak memory as each outer tuple is
353  * scanned. Note this assumes that we will recalculate *all* runtime keys
354  * on each call.
355  */
356  if (node->ioss_NumRuntimeKeys != 0)
357  {
358  ExprContext *econtext = node->ioss_RuntimeContext;
359 
360  ResetExprContext(econtext);
361  ExecIndexEvalRuntimeKeys(econtext,
362  node->ioss_RuntimeKeys,
363  node->ioss_NumRuntimeKeys);
364  }
365  node->ioss_RuntimeKeysReady = true;
366 
367  /* reset index scan */
368  if (node->ioss_ScanDesc)
369  {
370 
372  node->ioss_ScanKeys, node->ioss_NumScanKeys,
374 
375  if (reset_parallel_scan && node->ioss_ScanDesc->parallel_scan)
377  }
378  ExecScanReScan(&node->ss);
379 }
bool ioss_RuntimeKeysReady
Definition: execnodes.h:1236
ParallelIndexScanDesc parallel_scan
Definition: relscan.h:140
void index_rescan(IndexScanDesc scan, ScanKey keys, int nkeys, ScanKey orderbys, int norderbys)
Definition: indexam.c:310
IndexRuntimeKeyInfo * ioss_RuntimeKeys
Definition: execnodes.h:1234
void index_parallelrescan(IndexScanDesc scan)
Definition: indexam.c:481
ScanKey ioss_ScanKeys
Definition: execnodes.h:1230
ExprContext * ioss_RuntimeContext
Definition: execnodes.h:1237
IndexScanDesc ioss_ScanDesc
Definition: execnodes.h:1239
ScanKey ioss_OrderByKeys
Definition: execnodes.h:1232
void ExecIndexEvalRuntimeKeys(ExprContext *econtext, IndexRuntimeKeyInfo *runtimeKeys, int numRuntimeKeys)
void ExecScanReScan(ScanState *node)
Definition: execScan.c:327
#define ResetExprContext(econtext)
Definition: executor.h:469
static TupleTableSlot * IndexOnlyNext ( IndexOnlyScanState node)
static

Definition at line 56 of file nodeIndexonlyscan.c.

References Assert, BackwardScanDirection, CHECK_FOR_INTERRUPTS, 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().

57 {
58  EState *estate;
59  ExprContext *econtext;
60  ScanDirection direction;
61  IndexScanDesc scandesc;
62  TupleTableSlot *slot;
63  ItemPointer tid;
64 
65  /*
66  * extract necessary information from index scan node
67  */
68  estate = node->ss.ps.state;
69  direction = estate->es_direction;
70  /* flip direction if this is an overall backward scan */
71  if (ScanDirectionIsBackward(((IndexOnlyScan *) node->ss.ps.plan)->indexorderdir))
72  {
73  if (ScanDirectionIsForward(direction))
74  direction = BackwardScanDirection;
75  else if (ScanDirectionIsBackward(direction))
76  direction = ForwardScanDirection;
77  }
78  scandesc = node->ioss_ScanDesc;
79  econtext = node->ss.ps.ps_ExprContext;
80  slot = node->ss.ss_ScanTupleSlot;
81 
82  if (scandesc == NULL)
83  {
84  /*
85  * We reach here if the index only scan is not parallel, or if we're
86  * executing a index only scan that was intended to be parallel
87  * serially.
88  */
89  scandesc = index_beginscan(node->ss.ss_currentRelation,
90  node->ioss_RelationDesc,
91  estate->es_snapshot,
92  node->ioss_NumScanKeys,
93  node->ioss_NumOrderByKeys);
94 
95  node->ioss_ScanDesc = scandesc;
96 
97 
98  /* Set it up for index-only scan */
99  node->ioss_ScanDesc->xs_want_itup = true;
101 
102  /*
103  * If no run-time keys to calculate or they are ready, go ahead and
104  * pass the scankeys to the index AM.
105  */
106  if (node->ioss_NumRuntimeKeys == 0 || node->ioss_RuntimeKeysReady)
107  index_rescan(scandesc,
108  node->ioss_ScanKeys,
109  node->ioss_NumScanKeys,
110  node->ioss_OrderByKeys,
111  node->ioss_NumOrderByKeys);
112  }
113 
114  /*
115  * OK, now that we have what we need, fetch the next tuple.
116  */
117  while ((tid = index_getnext_tid(scandesc, direction)) != NULL)
118  {
119  HeapTuple tuple = NULL;
120 
122 
123  /*
124  * We can skip the heap fetch if the TID references a heap page on
125  * which all tuples are known visible to everybody. In any case,
126  * we'll use the index tuple not the heap tuple as the data source.
127  *
128  * Note on Memory Ordering Effects: visibilitymap_get_status does not
129  * lock the visibility map buffer, and therefore the result we read
130  * here could be slightly stale. However, it can't be stale enough to
131  * matter.
132  *
133  * We need to detect clearing a VM bit due to an insert right away,
134  * because the tuple is present in the index page but not visible. The
135  * reading of the TID by this scan (using a shared lock on the index
136  * buffer) is serialized with the insert of the TID into the index
137  * (using an exclusive lock on the index buffer). Because the VM bit
138  * is cleared before updating the index, and locking/unlocking of the
139  * index page acts as a full memory barrier, we are sure to see the
140  * cleared bit if we see a recently-inserted TID.
141  *
142  * Deletes do not update the index page (only VACUUM will clear out
143  * the TID), so the clearing of the VM bit by a delete is not
144  * serialized with this test below, and we may see a value that is
145  * significantly stale. However, we don't care about the delete right
146  * away, because the tuple is still visible until the deleting
147  * transaction commits or the statement ends (if it's our
148  * transaction). In either case, the lock on the VM buffer will have
149  * been released (acting as a write barrier) after clearing the bit.
150  * And for us to have a snapshot that includes the deleting
151  * transaction (making the tuple invisible), we must have acquired
152  * ProcArrayLock after that time, acting as a read barrier.
153  *
154  * It's worth going through this complexity to avoid needing to lock
155  * the VM buffer, which could cause significant contention.
156  */
157  if (!VM_ALL_VISIBLE(scandesc->heapRelation,
159  &node->ioss_VMBuffer))
160  {
161  /*
162  * Rats, we have to visit the heap to check visibility.
163  */
164  node->ioss_HeapFetches++;
165  tuple = index_fetch_heap(scandesc);
166  if (tuple == NULL)
167  continue; /* no visible tuple, try next index entry */
168 
169  /*
170  * Only MVCC snapshots are supported here, so there should be no
171  * need to keep following the HOT chain once a visible entry has
172  * been found. If we did want to allow that, we'd need to keep
173  * more state to remember not to call index_getnext_tid next time.
174  */
175  if (scandesc->xs_continue_hot)
176  elog(ERROR, "non-MVCC snapshots are not supported in index-only scans");
177 
178  /*
179  * Note: at this point we are holding a pin on the heap page, as
180  * recorded in scandesc->xs_cbuf. We could release that pin now,
181  * but it's not clear whether it's a win to do so. The next index
182  * entry might require a visit to the same heap page.
183  */
184  }
185 
186  /*
187  * Fill the scan tuple slot with data from the index. This might be
188  * provided in either HeapTuple or IndexTuple format. Conceivably an
189  * index AM might fill both fields, in which case we prefer the heap
190  * format, since it's probably a bit cheaper to fill a slot from.
191  */
192  if (scandesc->xs_hitup)
193  {
194  /*
195  * We don't take the trouble to verify that the provided tuple has
196  * exactly the slot's format, but it seems worth doing a quick
197  * check on the number of fields.
198  */
200  scandesc->xs_hitupdesc->natts);
201  ExecStoreTuple(scandesc->xs_hitup, slot, InvalidBuffer, false);
202  }
203  else if (scandesc->xs_itup)
204  StoreIndexTuple(slot, scandesc->xs_itup, scandesc->xs_itupdesc);
205  else
206  elog(ERROR, "no data returned for index-only scan");
207 
208  /*
209  * If the index was lossy, we have to recheck the index quals.
210  * (Currently, this can never happen, but we should support the case
211  * for possible future use, eg with GiST indexes.)
212  */
213  if (scandesc->xs_recheck)
214  {
215  econtext->ecxt_scantuple = slot;
216  ResetExprContext(econtext);
217  if (!ExecQual(node->indexqual, econtext))
218  {
219  /* Fails recheck, so drop it and loop back for another */
220  InstrCountFiltered2(node, 1);
221  continue;
222  }
223  }
224 
225  /*
226  * We don't currently support rechecking ORDER BY distances. (In
227  * principle, if the index can support retrieval of the originally
228  * indexed value, it should be able to produce an exact distance
229  * calculation too. So it's not clear that adding code here for
230  * recheck/re-sort would be worth the trouble. But we should at least
231  * throw an error if someone tries it.)
232  */
233  if (scandesc->numberOfOrderBys > 0 && scandesc->xs_recheckorderby)
234  ereport(ERROR,
235  (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
236  errmsg("lossy distance functions are not supported in index-only scans")));
237 
238  /*
239  * Predicate locks for index-only scans must be acquired at the page
240  * level when the heap is not accessed, since tuple-level predicate
241  * locks need the tuple's xmin value. If we had to visit the tuple
242  * anyway, then we already have the tuple-level lock and can skip the
243  * page lock.
244  */
245  if (tuple == NULL)
248  estate->es_snapshot);
249 
250  return slot;
251  }
252 
253  /*
254  * if we get here it means the index scan failed so we are at the end of
255  * the scan..
256  */
257  return ExecClearTuple(slot);
258 }
bool ioss_RuntimeKeysReady
Definition: execnodes.h:1236
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:2519
#define ScanDirectionIsForward(direction)
Definition: sdir.h:55
IndexTuple xs_itup
Definition: relscan.h:114
ExprContext * ps_ExprContext
Definition: execnodes.h:881
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:134
Snapshot es_snapshot
Definition: execnodes.h:429
TupleTableSlot * ss_ScanTupleSlot
Definition: execnodes.h:1101
TupleDesc xs_itupdesc
Definition: relscan.h:115
Relation ss_currentRelation
Definition: execnodes.h:1099
EState * state
Definition: execnodes.h:849
static bool ExecQual(ExprState *state, ExprContext *econtext)
Definition: executor.h:365
int natts
Definition: tupdesc.h:73
TupleDesc xs_hitupdesc
Definition: relscan.h:117
ScanDirection es_direction
Definition: execnodes.h:428
Relation heapRelation
Definition: relscan.h:89
PlanState ps
Definition: execnodes.h:1098
ScanKey ioss_ScanKeys
Definition: execnodes.h:1230
#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:1239
ScanDirection
Definition: sdir.h:22
bool xs_continue_hot
Definition: relscan.h:137
#define ereport(elevel, rest)
Definition: elog.h:122
ScanKey ioss_OrderByKeys
Definition: execnodes.h:1232
TupleDesc tts_tupleDescriptor
Definition: tuptable.h:121
Plan * plan
Definition: execnodes.h:847
Relation ioss_RelationDesc
Definition: execnodes.h:1238
bool xs_want_itup
Definition: relscan.h:96
#define NULL
Definition: c.h:229
#define Assert(condition)
Definition: c.h:676
static void StoreIndexTuple(TupleTableSlot *slot, IndexTuple itup, TupleDesc itupdesc)
#define InstrCountFiltered2(node, delta)
Definition: execnodes.h:901
#define VM_ALL_VISIBLE(r, b, v)
Definition: visibilitymap.h:32
ExprState * indexqual
Definition: execnodes.h:1229
TupleTableSlot * ecxt_scantuple
Definition: execnodes.h:197
int errmsg(const char *fmt,...)
Definition: elog.c:797
HeapTuple xs_hitup
Definition: relscan.h:116
#define CHECK_FOR_INTERRUPTS()
Definition: miscadmin.h:98
int numberOfOrderBys
Definition: relscan.h:93
#define elog
Definition: elog.h:219
#define ItemPointerGetBlockNumber(pointer)
Definition: itemptr.h:76
#define ResetExprContext(econtext)
Definition: executor.h:469
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 299 of file nodeIndexonlyscan.c.

References elog, and ERROR.

Referenced by ExecIndexOnlyScan().

300 {
301  elog(ERROR, "EvalPlanQual recheck is not supported in index-only scans");
302  return false; /* keep compiler quiet */
303 }
#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 268 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().

269 {
270  int nindexatts = itupdesc->natts;
271  Datum *values = slot->tts_values;
272  bool *isnull = slot->tts_isnull;
273  int i;
274 
275  /*
276  * Note: we must use the tupdesc supplied by the AM in index_getattr, not
277  * the slot's tupdesc, in case the latter has different datatypes (this
278  * happens for btree name_ops in particular). They'd better have the same
279  * number of columns though, as well as being datatype-compatible which is
280  * something we can't so easily check.
281  */
282  Assert(slot->tts_tupleDescriptor->natts == nindexatts);
283 
284  ExecClearTuple(slot);
285  for (i = 0; i < nindexatts; i++)
286  values[i] = index_getattr(itup, i + 1, itupdesc, &isnull[i]);
287  ExecStoreVirtualTuple(slot);
288 }
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:676
#define index_getattr(tup, attnum, tupleDesc, isnull)
Definition: itup.h:100
static Datum values[MAXATTR]
Definition: bootstrap.c:163
int i
TupleTableSlot * ExecStoreVirtualTuple(TupleTableSlot *slot)
Definition: execTuples.c:488