LCOV - code coverage report
Current view: top level - src/backend/executor - nodeIndexscan.c (source / functions) Hit Total Coverage
Test: PostgreSQL 12beta2 Lines: 472 544 86.8 %
Date: 2019-06-19 16:07:09 Functions: 22 22 100.0 %
Legend: Lines: hit not hit

          Line data    Source code
       1             : /*-------------------------------------------------------------------------
       2             :  *
       3             :  * nodeIndexscan.c
       4             :  *    Routines to support indexed scans of relations
       5             :  *
       6             :  * Portions Copyright (c) 1996-2019, PostgreSQL Global Development Group
       7             :  * Portions Copyright (c) 1994, Regents of the University of California
       8             :  *
       9             :  *
      10             :  * IDENTIFICATION
      11             :  *    src/backend/executor/nodeIndexscan.c
      12             :  *
      13             :  *-------------------------------------------------------------------------
      14             :  */
      15             : /*
      16             :  * INTERFACE ROUTINES
      17             :  *      ExecIndexScan           scans a relation using an index
      18             :  *      IndexNext               retrieve next tuple using index
      19             :  *      IndexNextWithReorder    same, but recheck ORDER BY expressions
      20             :  *      ExecInitIndexScan       creates and initializes state info.
      21             :  *      ExecReScanIndexScan     rescans the indexed relation.
      22             :  *      ExecEndIndexScan        releases all storage.
      23             :  *      ExecIndexMarkPos        marks scan position.
      24             :  *      ExecIndexRestrPos       restores scan position.
      25             :  *      ExecIndexScanEstimate   estimates DSM space needed for parallel index scan
      26             :  *      ExecIndexScanInitializeDSM initialize DSM for parallel indexscan
      27             :  *      ExecIndexScanReInitializeDSM reinitialize DSM for fresh scan
      28             :  *      ExecIndexScanInitializeWorker attach to DSM info in parallel worker
      29             :  */
      30             : #include "postgres.h"
      31             : 
      32             : #include "access/nbtree.h"
      33             : #include "access/relscan.h"
      34             : #include "access/tableam.h"
      35             : #include "catalog/pg_am.h"
      36             : #include "executor/execdebug.h"
      37             : #include "executor/nodeIndexscan.h"
      38             : #include "lib/pairingheap.h"
      39             : #include "miscadmin.h"
      40             : #include "nodes/nodeFuncs.h"
      41             : #include "utils/array.h"
      42             : #include "utils/datum.h"
      43             : #include "utils/lsyscache.h"
      44             : #include "utils/memutils.h"
      45             : #include "utils/rel.h"
      46             : 
      47             : /*
      48             :  * When an ordering operator is used, tuples fetched from the index that
      49             :  * need to be reordered are queued in a pairing heap, as ReorderTuples.
      50             :  */
      51             : typedef struct
      52             : {
      53             :     pairingheap_node ph_node;
      54             :     HeapTuple   htup;
      55             :     Datum      *orderbyvals;
      56             :     bool       *orderbynulls;
      57             : } ReorderTuple;
      58             : 
      59             : static TupleTableSlot *IndexNext(IndexScanState *node);
      60             : static TupleTableSlot *IndexNextWithReorder(IndexScanState *node);
      61             : static void EvalOrderByExpressions(IndexScanState *node, ExprContext *econtext);
      62             : static bool IndexRecheck(IndexScanState *node, TupleTableSlot *slot);
      63             : static int  cmp_orderbyvals(const Datum *adist, const bool *anulls,
      64             :                             const Datum *bdist, const bool *bnulls,
      65             :                             IndexScanState *node);
      66             : static int  reorderqueue_cmp(const pairingheap_node *a,
      67             :                              const pairingheap_node *b, void *arg);
      68             : static void reorderqueue_push(IndexScanState *node, TupleTableSlot *slot,
      69             :                               Datum *orderbyvals, bool *orderbynulls);
      70             : static HeapTuple reorderqueue_pop(IndexScanState *node);
      71             : 
      72             : 
      73             : /* ----------------------------------------------------------------
      74             :  *      IndexNext
      75             :  *
      76             :  *      Retrieve a tuple from the IndexScan node's currentRelation
      77             :  *      using the index specified in the IndexScanState information.
      78             :  * ----------------------------------------------------------------
      79             :  */
      80             : static TupleTableSlot *
      81     1187162 : IndexNext(IndexScanState *node)
      82             : {
      83             :     EState     *estate;
      84             :     ExprContext *econtext;
      85             :     ScanDirection direction;
      86             :     IndexScanDesc scandesc;
      87             :     TupleTableSlot *slot;
      88             : 
      89             :     /*
      90             :      * extract necessary information from index scan node
      91             :      */
      92     1187162 :     estate = node->ss.ps.state;
      93     1187162 :     direction = estate->es_direction;
      94             :     /* flip direction if this is an overall backward scan */
      95     1187162 :     if (ScanDirectionIsBackward(((IndexScan *) node->ss.ps.plan)->indexorderdir))
      96             :     {
      97         108 :         if (ScanDirectionIsForward(direction))
      98         108 :             direction = BackwardScanDirection;
      99           0 :         else if (ScanDirectionIsBackward(direction))
     100           0 :             direction = ForwardScanDirection;
     101             :     }
     102     1187162 :     scandesc = node->iss_ScanDesc;
     103     1187162 :     econtext = node->ss.ps.ps_ExprContext;
     104     1187162 :     slot = node->ss.ss_ScanTupleSlot;
     105             : 
     106     1187162 :     if (scandesc == NULL)
     107             :     {
     108             :         /*
     109             :          * We reach here if the index scan is not parallel, or if we're
     110             :          * serially executing an index scan that was planned to be parallel.
     111             :          */
     112       69656 :         scandesc = index_beginscan(node->ss.ss_currentRelation,
     113             :                                    node->iss_RelationDesc,
     114             :                                    estate->es_snapshot,
     115             :                                    node->iss_NumScanKeys,
     116             :                                    node->iss_NumOrderByKeys);
     117             : 
     118       69656 :         node->iss_ScanDesc = scandesc;
     119             : 
     120             :         /*
     121             :          * If no run-time keys to calculate or they are ready, go ahead and
     122             :          * pass the scankeys to the index AM.
     123             :          */
     124       69656 :         if (node->iss_NumRuntimeKeys == 0 || node->iss_RuntimeKeysReady)
     125      208968 :             index_rescan(scandesc,
     126       69656 :                          node->iss_ScanKeys, node->iss_NumScanKeys,
     127       69656 :                          node->iss_OrderByKeys, node->iss_NumOrderByKeys);
     128             :     }
     129             : 
     130             :     /*
     131             :      * ok, now that we have what we need, fetch the next tuple.
     132             :      */
     133     2383372 :     while (index_getnext_slot(scandesc, direction, slot))
     134             :     {
     135      986030 :         CHECK_FOR_INTERRUPTS();
     136             : 
     137             :         /*
     138             :          * If the index was lossy, we have to recheck the index quals using
     139             :          * the fetched tuple.
     140             :          */
     141      986030 :         if (scandesc->xs_recheck)
     142             :         {
     143       84248 :             econtext->ecxt_scantuple = slot;
     144       84248 :             if (!ExecQualAndReset(node->indexqualorig, econtext))
     145             :             {
     146             :                 /* Fails recheck, so drop it and loop back for another */
     147        9048 :                 InstrCountFiltered2(node, 1);
     148        9048 :                 continue;
     149             :             }
     150             :         }
     151             : 
     152      976982 :         return slot;
     153             :     }
     154             : 
     155             :     /*
     156             :      * if we get here it means the index scan failed so we are at the end of
     157             :      * the scan..
     158             :      */
     159      210178 :     node->iss_ReachedEnd = true;
     160      210178 :     return ExecClearTuple(slot);
     161             : }
     162             : 
     163             : /* ----------------------------------------------------------------
     164             :  *      IndexNextWithReorder
     165             :  *
     166             :  *      Like IndexNext, but this version can also re-check ORDER BY
     167             :  *      expressions, and reorder the tuples as necessary.
     168             :  * ----------------------------------------------------------------
     169             :  */
     170             : static TupleTableSlot *
     171        3446 : IndexNextWithReorder(IndexScanState *node)
     172             : {
     173             :     EState     *estate;
     174             :     ExprContext *econtext;
     175             :     IndexScanDesc scandesc;
     176             :     TupleTableSlot *slot;
     177        3446 :     ReorderTuple *topmost = NULL;
     178             :     bool        was_exact;
     179             :     Datum      *lastfetched_vals;
     180             :     bool       *lastfetched_nulls;
     181             :     int         cmp;
     182             : 
     183        3446 :     estate = node->ss.ps.state;
     184             : 
     185             :     /*
     186             :      * Only forward scan is supported with reordering.  Note: we can get away
     187             :      * with just Asserting here because the system will not try to run the
     188             :      * plan backwards if ExecSupportsBackwardScan() says it won't work.
     189             :      * Currently, that is guaranteed because no index AMs support both
     190             :      * amcanorderbyop and amcanbackward; if any ever do,
     191             :      * ExecSupportsBackwardScan() will need to consider indexorderbys
     192             :      * explicitly.
     193             :      */
     194             :     Assert(!ScanDirectionIsBackward(((IndexScan *) node->ss.ps.plan)->indexorderdir));
     195             :     Assert(ScanDirectionIsForward(estate->es_direction));
     196             : 
     197        3446 :     scandesc = node->iss_ScanDesc;
     198        3446 :     econtext = node->ss.ps.ps_ExprContext;
     199        3446 :     slot = node->ss.ss_ScanTupleSlot;
     200             : 
     201        3446 :     if (scandesc == NULL)
     202             :     {
     203             :         /*
     204             :          * We reach here if the index scan is not parallel, or if we're
     205             :          * serially executing an index scan that was planned to be parallel.
     206             :          */
     207          20 :         scandesc = index_beginscan(node->ss.ss_currentRelation,
     208             :                                    node->iss_RelationDesc,
     209             :                                    estate->es_snapshot,
     210             :                                    node->iss_NumScanKeys,
     211             :                                    node->iss_NumOrderByKeys);
     212             : 
     213          20 :         node->iss_ScanDesc = scandesc;
     214             : 
     215             :         /*
     216             :          * If no run-time keys to calculate or they are ready, go ahead and
     217             :          * pass the scankeys to the index AM.
     218             :          */
     219          20 :         if (node->iss_NumRuntimeKeys == 0 || node->iss_RuntimeKeysReady)
     220          60 :             index_rescan(scandesc,
     221          20 :                          node->iss_ScanKeys, node->iss_NumScanKeys,
     222          20 :                          node->iss_OrderByKeys, node->iss_NumOrderByKeys);
     223             :     }
     224             : 
     225             :     for (;;)
     226             :     {
     227       10298 :         CHECK_FOR_INTERRUPTS();
     228             : 
     229             :         /*
     230             :          * Check the reorder queue first.  If the topmost tuple in the queue
     231             :          * has an ORDER BY value smaller than (or equal to) the value last
     232             :          * returned by the index, we can return it now.
     233             :          */
     234        6872 :         if (!pairingheap_is_empty(node->iss_ReorderQueue))
     235             :         {
     236        6812 :             topmost = (ReorderTuple *) pairingheap_first(node->iss_ReorderQueue);
     237             : 
     238       13620 :             if (node->iss_ReachedEnd ||
     239        6808 :                 cmp_orderbyvals(topmost->orderbyvals,
     240        6808 :                                 topmost->orderbynulls,
     241        6808 :                                 scandesc->xs_orderbyvals,
     242        6808 :                                 scandesc->xs_orderbynulls,
     243             :                                 node) <= 0)
     244             :             {
     245             :                 HeapTuple   tuple;
     246             : 
     247        3390 :                 tuple = reorderqueue_pop(node);
     248             : 
     249             :                 /* Pass 'true', as the tuple in the queue is a palloc'd copy */
     250        3390 :                 ExecForceStoreHeapTuple(tuple, slot, true);
     251        3390 :                 return slot;
     252             :             }
     253             :         }
     254          60 :         else if (node->iss_ReachedEnd)
     255             :         {
     256             :             /* Queue is empty, and no more tuples from index.  We're done. */
     257           4 :             return ExecClearTuple(slot);
     258             :         }
     259             : 
     260             :         /*
     261             :          * Fetch next tuple from the index.
     262             :          */
     263             : next_indextuple:
     264        6238 :         if (!index_getnext_slot(scandesc, ForwardScanDirection, slot))
     265             :         {
     266             :             /*
     267             :              * No more tuples from the index.  But we still need to drain any
     268             :              * remaining tuples from the queue before we're done.
     269             :              */
     270           4 :             node->iss_ReachedEnd = true;
     271           4 :             continue;
     272             :         }
     273             : 
     274             :         /*
     275             :          * If the index was lossy, we have to recheck the index quals and
     276             :          * ORDER BY expressions using the fetched tuple.
     277             :          */
     278        6234 :         if (scandesc->xs_recheck)
     279             :         {
     280        6084 :             econtext->ecxt_scantuple = slot;
     281        6084 :             if (!ExecQualAndReset(node->indexqualorig, econtext))
     282             :             {
     283             :                 /* Fails recheck, so drop it and loop back for another */
     284        2760 :                 InstrCountFiltered2(node, 1);
     285             :                 /* allow this loop to be cancellable */
     286        2760 :                 CHECK_FOR_INTERRUPTS();
     287        2760 :                 goto next_indextuple;
     288             :             }
     289             :         }
     290             : 
     291        3474 :         if (scandesc->xs_recheckorderby)
     292             :         {
     293        3464 :             econtext->ecxt_scantuple = slot;
     294        3464 :             ResetExprContext(econtext);
     295        3464 :             EvalOrderByExpressions(node, econtext);
     296             : 
     297             :             /*
     298             :              * Was the ORDER BY value returned by the index accurate?  The
     299             :              * recheck flag means that the index can return inaccurate values,
     300             :              * but then again, the value returned for any particular tuple
     301             :              * could also be exactly correct.  Compare the value returned by
     302             :              * the index with the recalculated value.  (If the value returned
     303             :              * by the index happened to be exact right, we can often avoid
     304             :              * pushing the tuple to the queue, just to pop it back out again.)
     305             :              */
     306        3464 :             cmp = cmp_orderbyvals(node->iss_OrderByValues,
     307        3464 :                                   node->iss_OrderByNulls,
     308        3464 :                                   scandesc->xs_orderbyvals,
     309        3464 :                                   scandesc->xs_orderbynulls,
     310             :                                   node);
     311        3464 :             if (cmp < 0)
     312           0 :                 elog(ERROR, "index returned tuples in wrong order");
     313        3464 :             else if (cmp == 0)
     314          46 :                 was_exact = true;
     315             :             else
     316        3418 :                 was_exact = false;
     317        3464 :             lastfetched_vals = node->iss_OrderByValues;
     318        3464 :             lastfetched_nulls = node->iss_OrderByNulls;
     319             :         }
     320             :         else
     321             :         {
     322          10 :             was_exact = true;
     323          10 :             lastfetched_vals = scandesc->xs_orderbyvals;
     324          10 :             lastfetched_nulls = scandesc->xs_orderbynulls;
     325             :         }
     326             : 
     327             :         /*
     328             :          * Can we return this tuple immediately, or does it need to be pushed
     329             :          * to the reorder queue?  If the ORDER BY expression values returned
     330             :          * by the index were inaccurate, we can't return it yet, because the
     331             :          * next tuple from the index might need to come before this one. Also,
     332             :          * we can't return it yet if there are any smaller tuples in the queue
     333             :          * already.
     334             :          */
     335        3490 :         if (!was_exact || (topmost && cmp_orderbyvals(lastfetched_vals,
     336             :                                                       lastfetched_nulls,
     337          16 :                                                       topmost->orderbyvals,
     338          16 :                                                       topmost->orderbynulls,
     339             :                                                       node) > 0))
     340             :         {
     341             :             /* Put this tuple to the queue */
     342        3422 :             reorderqueue_push(node, slot, lastfetched_vals, lastfetched_nulls);
     343        3422 :             continue;
     344             :         }
     345             :         else
     346             :         {
     347             :             /* Can return this tuple immediately. */
     348          52 :             return slot;
     349             :         }
     350             :     }
     351             : 
     352             :     /*
     353             :      * if we get here it means the index scan failed so we are at the end of
     354             :      * the scan..
     355             :      */
     356             :     return ExecClearTuple(slot);
     357             : }
     358             : 
     359             : /*
     360             :  * Calculate the expressions in the ORDER BY clause, based on the heap tuple.
     361             :  */
     362             : static void
     363        3464 : EvalOrderByExpressions(IndexScanState *node, ExprContext *econtext)
     364             : {
     365             :     int         i;
     366             :     ListCell   *l;
     367             :     MemoryContext oldContext;
     368             : 
     369        3464 :     oldContext = MemoryContextSwitchTo(econtext->ecxt_per_tuple_memory);
     370             : 
     371        3464 :     i = 0;
     372        6928 :     foreach(l, node->indexorderbyorig)
     373             :     {
     374        3464 :         ExprState  *orderby = (ExprState *) lfirst(l);
     375             : 
     376        6928 :         node->iss_OrderByValues[i] = ExecEvalExpr(orderby,
     377             :                                                   econtext,
     378        3464 :                                                   &node->iss_OrderByNulls[i]);
     379        3464 :         i++;
     380             :     }
     381             : 
     382        3464 :     MemoryContextSwitchTo(oldContext);
     383        3464 : }
     384             : 
     385             : /*
     386             :  * IndexRecheck -- access method routine to recheck a tuple in EvalPlanQual
     387             :  */
     388             : static bool
     389          48 : IndexRecheck(IndexScanState *node, TupleTableSlot *slot)
     390             : {
     391             :     ExprContext *econtext;
     392             : 
     393             :     /*
     394             :      * extract necessary information from index scan node
     395             :      */
     396          48 :     econtext = node->ss.ps.ps_ExprContext;
     397             : 
     398             :     /* Does the tuple meet the indexqual condition? */
     399          48 :     econtext->ecxt_scantuple = slot;
     400          48 :     return ExecQualAndReset(node->indexqualorig, econtext);
     401             : }
     402             : 
     403             : 
     404             : /*
     405             :  * Compare ORDER BY expression values.
     406             :  */
     407             : static int
     408       19374 : cmp_orderbyvals(const Datum *adist, const bool *anulls,
     409             :                 const Datum *bdist, const bool *bnulls,
     410             :                 IndexScanState *node)
     411             : {
     412             :     int         i;
     413             :     int         result;
     414             : 
     415       19462 :     for (i = 0; i < node->iss_NumOrderByKeys; i++)
     416             :     {
     417       19374 :         SortSupport ssup = &node->iss_SortSupport[i];
     418             : 
     419             :         /*
     420             :          * Handle nulls.  We only need to support NULLS LAST ordering, because
     421             :          * match_pathkeys_to_index() doesn't consider indexorderby
     422             :          * implementation otherwise.
     423             :          */
     424       19374 :         if (anulls[i] && !bnulls[i])
     425           0 :             return 1;
     426       19374 :         else if (!anulls[i] && bnulls[i])
     427           0 :             return -1;
     428       19374 :         else if (anulls[i] && bnulls[i])
     429           0 :             return 0;
     430             : 
     431       19374 :         result = ssup->comparator(adist[i], bdist[i], ssup);
     432       19374 :         if (result != 0)
     433       19286 :             return result;
     434             :     }
     435             : 
     436          88 :     return 0;
     437             : }
     438             : 
     439             : /*
     440             :  * Pairing heap provides getting topmost (greatest) element while KNN provides
     441             :  * ascending sort.  That's why we invert the sort order.
     442             :  */
     443             : static int
     444        9086 : reorderqueue_cmp(const pairingheap_node *a, const pairingheap_node *b,
     445             :                  void *arg)
     446             : {
     447        9086 :     ReorderTuple *rta = (ReorderTuple *) a;
     448        9086 :     ReorderTuple *rtb = (ReorderTuple *) b;
     449        9086 :     IndexScanState *node = (IndexScanState *) arg;
     450             : 
     451             :     /* exchange argument order to invert the sort order */
     452        9086 :     return cmp_orderbyvals(rtb->orderbyvals, rtb->orderbynulls,
     453        9086 :                            rta->orderbyvals, rta->orderbynulls,
     454             :                            node);
     455             : }
     456             : 
     457             : /*
     458             :  * Helper function to push a tuple to the reorder queue.
     459             :  */
     460             : static void
     461        3422 : reorderqueue_push(IndexScanState *node, TupleTableSlot *slot,
     462             :                   Datum *orderbyvals, bool *orderbynulls)
     463             : {
     464        3422 :     IndexScanDesc scandesc = node->iss_ScanDesc;
     465        3422 :     EState     *estate = node->ss.ps.state;
     466        3422 :     MemoryContext oldContext = MemoryContextSwitchTo(estate->es_query_cxt);
     467             :     ReorderTuple *rt;
     468             :     int         i;
     469             : 
     470        3422 :     rt = (ReorderTuple *) palloc(sizeof(ReorderTuple));
     471        3422 :     rt->htup = ExecCopySlotHeapTuple(slot);
     472        3422 :     rt->orderbyvals =
     473        3422 :         (Datum *) palloc(sizeof(Datum) * scandesc->numberOfOrderBys);
     474        3422 :     rt->orderbynulls =
     475        3422 :         (bool *) palloc(sizeof(bool) * scandesc->numberOfOrderBys);
     476        6844 :     for (i = 0; i < node->iss_NumOrderByKeys; i++)
     477             :     {
     478        3422 :         if (!orderbynulls[i])
     479       10266 :             rt->orderbyvals[i] = datumCopy(orderbyvals[i],
     480        3422 :                                            node->iss_OrderByTypByVals[i],
     481        3422 :                                            node->iss_OrderByTypLens[i]);
     482             :         else
     483           0 :             rt->orderbyvals[i] = (Datum) 0;
     484        3422 :         rt->orderbynulls[i] = orderbynulls[i];
     485             :     }
     486        3422 :     pairingheap_add(node->iss_ReorderQueue, &rt->ph_node);
     487             : 
     488        3422 :     MemoryContextSwitchTo(oldContext);
     489        3422 : }
     490             : 
     491             : /*
     492             :  * Helper function to pop the next tuple from the reorder queue.
     493             :  */
     494             : static HeapTuple
     495        3390 : reorderqueue_pop(IndexScanState *node)
     496             : {
     497             :     HeapTuple   result;
     498             :     ReorderTuple *topmost;
     499             :     int         i;
     500             : 
     501        3390 :     topmost = (ReorderTuple *) pairingheap_remove_first(node->iss_ReorderQueue);
     502             : 
     503        3390 :     result = topmost->htup;
     504        6780 :     for (i = 0; i < node->iss_NumOrderByKeys; i++)
     505             :     {
     506        3390 :         if (!node->iss_OrderByTypByVals[i] && !topmost->orderbynulls[i])
     507           0 :             pfree(DatumGetPointer(topmost->orderbyvals[i]));
     508             :     }
     509        3390 :     pfree(topmost->orderbyvals);
     510        3390 :     pfree(topmost->orderbynulls);
     511        3390 :     pfree(topmost);
     512             : 
     513        3390 :     return result;
     514             : }
     515             : 
     516             : 
     517             : /* ----------------------------------------------------------------
     518             :  *      ExecIndexScan(node)
     519             :  * ----------------------------------------------------------------
     520             :  */
     521             : static TupleTableSlot *
     522     1153106 : ExecIndexScan(PlanState *pstate)
     523             : {
     524     1153106 :     IndexScanState *node = castNode(IndexScanState, pstate);
     525             : 
     526             :     /*
     527             :      * If we have runtime keys and they've not already been set up, do it now.
     528             :      */
     529     1153106 :     if (node->iss_NumRuntimeKeys != 0 && !node->iss_RuntimeKeysReady)
     530        7346 :         ExecReScan((PlanState *) node);
     531             : 
     532     1153102 :     if (node->iss_NumOrderByKeys > 0)
     533        3446 :         return ExecScan(&node->ss,
     534             :                         (ExecScanAccessMtd) IndexNextWithReorder,
     535             :                         (ExecScanRecheckMtd) IndexRecheck);
     536             :     else
     537     1149656 :         return ExecScan(&node->ss,
     538             :                         (ExecScanAccessMtd) IndexNext,
     539             :                         (ExecScanRecheckMtd) IndexRecheck);
     540             : }
     541             : 
     542             : /* ----------------------------------------------------------------
     543             :  *      ExecReScanIndexScan(node)
     544             :  *
     545             :  *      Recalculates the values of any scan keys whose value depends on
     546             :  *      information known at runtime, then rescans the indexed relation.
     547             :  *
     548             :  *      Updating the scan key was formerly done separately in
     549             :  *      ExecUpdateIndexScanKeys. Integrating it into ReScan makes
     550             :  *      rescans of indices and relations/general streams more uniform.
     551             :  * ----------------------------------------------------------------
     552             :  */
     553             : void
     554      210968 : ExecReScanIndexScan(IndexScanState *node)
     555             : {
     556             :     /*
     557             :      * If we are doing runtime key calculations (ie, any of the index key
     558             :      * values weren't simple Consts), compute the new key values.  But first,
     559             :      * reset the context so we don't leak memory as each outer tuple is
     560             :      * scanned.  Note this assumes that we will recalculate *all* runtime keys
     561             :      * on each call.
     562             :      */
     563      210968 :     if (node->iss_NumRuntimeKeys != 0)
     564             :     {
     565      205644 :         ExprContext *econtext = node->iss_RuntimeContext;
     566             : 
     567      205644 :         ResetExprContext(econtext);
     568      205644 :         ExecIndexEvalRuntimeKeys(econtext,
     569             :                                  node->iss_RuntimeKeys,
     570             :                                  node->iss_NumRuntimeKeys);
     571             :     }
     572      210964 :     node->iss_RuntimeKeysReady = true;
     573             : 
     574             :     /* flush the reorder queue */
     575      210964 :     if (node->iss_ReorderQueue)
     576             :     {
     577           0 :         while (!pairingheap_is_empty(node->iss_ReorderQueue))
     578           0 :             reorderqueue_pop(node);
     579             :     }
     580             : 
     581             :     /* reset index scan */
     582      210964 :     if (node->iss_ScanDesc)
     583      549744 :         index_rescan(node->iss_ScanDesc,
     584      183248 :                      node->iss_ScanKeys, node->iss_NumScanKeys,
     585      183248 :                      node->iss_OrderByKeys, node->iss_NumOrderByKeys);
     586      210964 :     node->iss_ReachedEnd = false;
     587             : 
     588      210964 :     ExecScanReScan(&node->ss);
     589      210964 : }
     590             : 
     591             : 
     592             : /*
     593             :  * ExecIndexEvalRuntimeKeys
     594             :  *      Evaluate any runtime key values, and update the scankeys.
     595             :  */
     596             : void
     597      217196 : ExecIndexEvalRuntimeKeys(ExprContext *econtext,
     598             :                          IndexRuntimeKeyInfo *runtimeKeys, int numRuntimeKeys)
     599             : {
     600             :     int         j;
     601             :     MemoryContext oldContext;
     602             : 
     603             :     /* We want to keep the key values in per-tuple memory */
     604      217196 :     oldContext = MemoryContextSwitchTo(econtext->ecxt_per_tuple_memory);
     605             : 
     606      444370 :     for (j = 0; j < numRuntimeKeys; j++)
     607             :     {
     608      227178 :         ScanKey     scan_key = runtimeKeys[j].scan_key;
     609      227178 :         ExprState  *key_expr = runtimeKeys[j].key_expr;
     610             :         Datum       scanvalue;
     611             :         bool        isNull;
     612             : 
     613             :         /*
     614             :          * For each run-time key, extract the run-time expression and evaluate
     615             :          * it with respect to the current context.  We then stick the result
     616             :          * into the proper scan key.
     617             :          *
     618             :          * Note: the result of the eval could be a pass-by-ref value that's
     619             :          * stored in some outer scan's tuple, not in
     620             :          * econtext->ecxt_per_tuple_memory.  We assume that the outer tuple
     621             :          * will stay put throughout our scan.  If this is wrong, we could copy
     622             :          * the result into our context explicitly, but I think that's not
     623             :          * necessary.
     624             :          *
     625             :          * It's also entirely possible that the result of the eval is a
     626             :          * toasted value.  In this case we should forcibly detoast it, to
     627             :          * avoid repeat detoastings each time the value is examined by an
     628             :          * index support function.
     629             :          */
     630      227178 :         scanvalue = ExecEvalExpr(key_expr,
     631             :                                  econtext,
     632             :                                  &isNull);
     633      227174 :         if (isNull)
     634             :         {
     635         666 :             scan_key->sk_argument = scanvalue;
     636         666 :             scan_key->sk_flags |= SK_ISNULL;
     637             :         }
     638             :         else
     639             :         {
     640      226508 :             if (runtimeKeys[j].key_toastable)
     641        2046 :                 scanvalue = PointerGetDatum(PG_DETOAST_DATUM(scanvalue));
     642      226508 :             scan_key->sk_argument = scanvalue;
     643      226508 :             scan_key->sk_flags &= ~SK_ISNULL;
     644             :         }
     645             :     }
     646             : 
     647      217192 :     MemoryContextSwitchTo(oldContext);
     648      217192 : }
     649             : 
     650             : /*
     651             :  * ExecIndexEvalArrayKeys
     652             :  *      Evaluate any array key values, and set up to iterate through arrays.
     653             :  *
     654             :  * Returns true if there are array elements to consider; false means there
     655             :  * is at least one null or empty array, so no match is possible.  On true
     656             :  * result, the scankeys are initialized with the first elements of the arrays.
     657             :  */
     658             : bool
     659           8 : ExecIndexEvalArrayKeys(ExprContext *econtext,
     660             :                        IndexArrayKeyInfo *arrayKeys, int numArrayKeys)
     661             : {
     662           8 :     bool        result = true;
     663             :     int         j;
     664             :     MemoryContext oldContext;
     665             : 
     666             :     /* We want to keep the arrays in per-tuple memory */
     667           8 :     oldContext = MemoryContextSwitchTo(econtext->ecxt_per_tuple_memory);
     668             : 
     669          32 :     for (j = 0; j < numArrayKeys; j++)
     670             :     {
     671           8 :         ScanKey     scan_key = arrayKeys[j].scan_key;
     672           8 :         ExprState  *array_expr = arrayKeys[j].array_expr;
     673             :         Datum       arraydatum;
     674             :         bool        isNull;
     675             :         ArrayType  *arrayval;
     676             :         int16       elmlen;
     677             :         bool        elmbyval;
     678             :         char        elmalign;
     679             :         int         num_elems;
     680             :         Datum      *elem_values;
     681             :         bool       *elem_nulls;
     682             : 
     683             :         /*
     684             :          * Compute and deconstruct the array expression. (Notes in
     685             :          * ExecIndexEvalRuntimeKeys() apply here too.)
     686             :          */
     687           8 :         arraydatum = ExecEvalExpr(array_expr,
     688             :                                   econtext,
     689             :                                   &isNull);
     690           8 :         if (isNull)
     691             :         {
     692           0 :             result = false;
     693           0 :             break;              /* no point in evaluating more */
     694             :         }
     695           8 :         arrayval = DatumGetArrayTypeP(arraydatum);
     696             :         /* We could cache this data, but not clear it's worth it */
     697           8 :         get_typlenbyvalalign(ARR_ELEMTYPE(arrayval),
     698             :                              &elmlen, &elmbyval, &elmalign);
     699           8 :         deconstruct_array(arrayval,
     700             :                           ARR_ELEMTYPE(arrayval),
     701             :                           elmlen, elmbyval, elmalign,
     702             :                           &elem_values, &elem_nulls, &num_elems);
     703           8 :         if (num_elems <= 0)
     704             :         {
     705           0 :             result = false;
     706           0 :             break;              /* no point in evaluating more */
     707             :         }
     708             : 
     709             :         /*
     710             :          * Note: we expect the previous array data, if any, to be
     711             :          * automatically freed by resetting the per-tuple context; hence no
     712             :          * pfree's here.
     713             :          */
     714           8 :         arrayKeys[j].elem_values = elem_values;
     715           8 :         arrayKeys[j].elem_nulls = elem_nulls;
     716           8 :         arrayKeys[j].num_elems = num_elems;
     717           8 :         scan_key->sk_argument = elem_values[0];
     718           8 :         if (elem_nulls[0])
     719           0 :             scan_key->sk_flags |= SK_ISNULL;
     720             :         else
     721           8 :             scan_key->sk_flags &= ~SK_ISNULL;
     722           8 :         arrayKeys[j].next_elem = 1;
     723             :     }
     724             : 
     725           8 :     MemoryContextSwitchTo(oldContext);
     726             : 
     727           8 :     return result;
     728             : }
     729             : 
     730             : /*
     731             :  * ExecIndexAdvanceArrayKeys
     732             :  *      Advance to the next set of array key values, if any.
     733             :  *
     734             :  * Returns true if there is another set of values to consider, false if not.
     735             :  * On true result, the scankeys are initialized with the next set of values.
     736             :  */
     737             : bool
     738       13666 : ExecIndexAdvanceArrayKeys(IndexArrayKeyInfo *arrayKeys, int numArrayKeys)
     739             : {
     740       13666 :     bool        found = false;
     741             :     int         j;
     742             : 
     743             :     /*
     744             :      * Note we advance the rightmost array key most quickly, since it will
     745             :      * correspond to the lowest-order index column among the available
     746             :      * qualifications.  This is hypothesized to result in better locality of
     747             :      * access in the index.
     748             :      */
     749       13674 :     for (j = numArrayKeys - 1; j >= 0; j--)
     750             :     {
     751          16 :         ScanKey     scan_key = arrayKeys[j].scan_key;
     752          16 :         int         next_elem = arrayKeys[j].next_elem;
     753          16 :         int         num_elems = arrayKeys[j].num_elems;
     754          16 :         Datum      *elem_values = arrayKeys[j].elem_values;
     755          16 :         bool       *elem_nulls = arrayKeys[j].elem_nulls;
     756             : 
     757          16 :         if (next_elem >= num_elems)
     758             :         {
     759           8 :             next_elem = 0;
     760           8 :             found = false;      /* need to advance next array key */
     761             :         }
     762             :         else
     763           8 :             found = true;
     764          16 :         scan_key->sk_argument = elem_values[next_elem];
     765          16 :         if (elem_nulls[next_elem])
     766           0 :             scan_key->sk_flags |= SK_ISNULL;
     767             :         else
     768          16 :             scan_key->sk_flags &= ~SK_ISNULL;
     769          16 :         arrayKeys[j].next_elem = next_elem + 1;
     770          16 :         if (found)
     771           8 :             break;
     772             :     }
     773             : 
     774       13666 :     return found;
     775             : }
     776             : 
     777             : 
     778             : /* ----------------------------------------------------------------
     779             :  *      ExecEndIndexScan
     780             :  * ----------------------------------------------------------------
     781             :  */
     782             : void
     783       79038 : ExecEndIndexScan(IndexScanState *node)
     784             : {
     785             :     Relation    indexRelationDesc;
     786             :     IndexScanDesc indexScanDesc;
     787             : 
     788             :     /*
     789             :      * extract information from the node
     790             :      */
     791       79038 :     indexRelationDesc = node->iss_RelationDesc;
     792       79038 :     indexScanDesc = node->iss_ScanDesc;
     793             : 
     794             :     /*
     795             :      * Free the exprcontext(s) ... now dead code, see ExecFreeExprContext
     796             :      */
     797             : #ifdef NOT_USED
     798             :     ExecFreeExprContext(&node->ss.ps);
     799             :     if (node->iss_RuntimeContext)
     800             :         FreeExprContext(node->iss_RuntimeContext, true);
     801             : #endif
     802             : 
     803             :     /*
     804             :      * clear out tuple table slots
     805             :      */
     806       79038 :     if (node->ss.ps.ps_ResultTupleSlot)
     807       37658 :         ExecClearTuple(node->ss.ps.ps_ResultTupleSlot);
     808       79038 :     ExecClearTuple(node->ss.ss_ScanTupleSlot);
     809             : 
     810             :     /*
     811             :      * close the index relation (no-op if we didn't open it)
     812             :      */
     813       79038 :     if (indexScanDesc)
     814       69438 :         index_endscan(indexScanDesc);
     815       79038 :     if (indexRelationDesc)
     816       77476 :         index_close(indexRelationDesc, NoLock);
     817       79038 : }
     818             : 
     819             : /* ----------------------------------------------------------------
     820             :  *      ExecIndexMarkPos
     821             :  *
     822             :  * Note: we assume that no caller attempts to set a mark before having read
     823             :  * at least one tuple.  Otherwise, iss_ScanDesc might still be NULL.
     824             :  * ----------------------------------------------------------------
     825             :  */
     826             : void
     827        4026 : ExecIndexMarkPos(IndexScanState *node)
     828             : {
     829        4026 :     EState     *estate = node->ss.ps.state;
     830             : 
     831        4026 :     if (estate->es_epqTupleSlot != NULL)
     832             :     {
     833             :         /*
     834             :          * We are inside an EvalPlanQual recheck.  If a test tuple exists for
     835             :          * this relation, then we shouldn't access the index at all.  We would
     836             :          * instead need to save, and later restore, the state of the
     837             :          * es_epqScanDone flag, so that re-fetching the test tuple is
     838             :          * possible.  However, given the assumption that no caller sets a mark
     839             :          * at the start of the scan, we can only get here with es_epqScanDone
     840             :          * already set, and so no state need be saved.
     841             :          */
     842           2 :         Index       scanrelid = ((Scan *) node->ss.ps.plan)->scanrelid;
     843             : 
     844             :         Assert(scanrelid > 0);
     845           2 :         if (estate->es_epqTupleSlot[scanrelid - 1] != NULL)
     846             :         {
     847             :             /* Verify the claim above */
     848           2 :             if (!estate->es_epqScanDone[scanrelid - 1])
     849           0 :                 elog(ERROR, "unexpected ExecIndexMarkPos call in EPQ recheck");
     850           2 :             return;
     851             :         }
     852             :     }
     853             : 
     854        4024 :     index_markpos(node->iss_ScanDesc);
     855             : }
     856             : 
     857             : /* ----------------------------------------------------------------
     858             :  *      ExecIndexRestrPos
     859             :  * ----------------------------------------------------------------
     860             :  */
     861             : void
     862       36004 : ExecIndexRestrPos(IndexScanState *node)
     863             : {
     864       36004 :     EState     *estate = node->ss.ps.state;
     865             : 
     866       36004 :     if (estate->es_epqTupleSlot != NULL)
     867             :     {
     868             :         /* See comments in ExecIndexMarkPos */
     869           0 :         Index       scanrelid = ((Scan *) node->ss.ps.plan)->scanrelid;
     870             : 
     871             :         Assert(scanrelid > 0);
     872           0 :         if (estate->es_epqTupleSlot[scanrelid - 1] != NULL)
     873             :         {
     874             :             /* Verify the claim above */
     875           0 :             if (!estate->es_epqScanDone[scanrelid - 1])
     876           0 :                 elog(ERROR, "unexpected ExecIndexRestrPos call in EPQ recheck");
     877           0 :             return;
     878             :         }
     879             :     }
     880             : 
     881       36004 :     index_restrpos(node->iss_ScanDesc);
     882             : }
     883             : 
     884             : /* ----------------------------------------------------------------
     885             :  *      ExecInitIndexScan
     886             :  *
     887             :  *      Initializes the index scan's state information, creates
     888             :  *      scan keys, and opens the base and index relations.
     889             :  *
     890             :  *      Note: index scans have 2 sets of state information because
     891             :  *            we have to keep track of the base relation and the
     892             :  *            index relation.
     893             :  * ----------------------------------------------------------------
     894             :  */
     895             : IndexScanState *
     896       79384 : ExecInitIndexScan(IndexScan *node, EState *estate, int eflags)
     897             : {
     898             :     IndexScanState *indexstate;
     899             :     Relation    currentRelation;
     900             :     LOCKMODE    lockmode;
     901             : 
     902             :     /*
     903             :      * create state structure
     904             :      */
     905       79384 :     indexstate = makeNode(IndexScanState);
     906       79384 :     indexstate->ss.ps.plan = (Plan *) node;
     907       79384 :     indexstate->ss.ps.state = estate;
     908       79384 :     indexstate->ss.ps.ExecProcNode = ExecIndexScan;
     909             : 
     910             :     /*
     911             :      * Miscellaneous initialization
     912             :      *
     913             :      * create expression context for node
     914             :      */
     915       79384 :     ExecAssignExprContext(estate, &indexstate->ss.ps);
     916             : 
     917             :     /*
     918             :      * open the scan relation
     919             :      */
     920       79384 :     currentRelation = ExecOpenScanRelation(estate, node->scan.scanrelid, eflags);
     921             : 
     922       79384 :     indexstate->ss.ss_currentRelation = currentRelation;
     923       79384 :     indexstate->ss.ss_currentScanDesc = NULL;    /* no heap scan here */
     924             : 
     925             :     /*
     926             :      * get the scan type from the relation descriptor.
     927             :      */
     928       79384 :     ExecInitScanTupleSlot(estate, &indexstate->ss,
     929             :                           RelationGetDescr(currentRelation),
     930             :                           table_slot_callbacks(currentRelation));
     931             : 
     932             :     /*
     933             :      * Initialize result type and projection.
     934             :      */
     935       79384 :     ExecInitResultTypeTL(&indexstate->ss.ps);
     936       79384 :     ExecAssignScanProjectionInfo(&indexstate->ss);
     937             : 
     938             :     /*
     939             :      * initialize child expressions
     940             :      *
     941             :      * Note: we don't initialize all of the indexqual expression, only the
     942             :      * sub-parts corresponding to runtime keys (see below).  Likewise for
     943             :      * indexorderby, if any.  But the indexqualorig expression is always
     944             :      * initialized even though it will only be used in some uncommon cases ---
     945             :      * would be nice to improve that.  (Problem is that any SubPlans present
     946             :      * in the expression must be found now...)
     947             :      */
     948       79384 :     indexstate->ss.ps.qual =
     949       79384 :         ExecInitQual(node->scan.plan.qual, (PlanState *) indexstate);
     950       79384 :     indexstate->indexqualorig =
     951       79384 :         ExecInitQual(node->indexqualorig, (PlanState *) indexstate);
     952       79384 :     indexstate->indexorderbyorig =
     953       79384 :         ExecInitExprList(node->indexorderbyorig, (PlanState *) indexstate);
     954             : 
     955             :     /*
     956             :      * If we are just doing EXPLAIN (ie, aren't going to run the plan), stop
     957             :      * here.  This allows an index-advisor plugin to EXPLAIN a plan containing
     958             :      * references to nonexistent indexes.
     959             :      */
     960       79384 :     if (eflags & EXEC_FLAG_EXPLAIN_ONLY)
     961        1562 :         return indexstate;
     962             : 
     963             :     /* Open the index relation. */
     964       77822 :     lockmode = exec_rt_fetch(node->scan.scanrelid, estate)->rellockmode;
     965       77822 :     indexstate->iss_RelationDesc = index_open(node->indexid, lockmode);
     966             : 
     967             :     /*
     968             :      * Initialize index-specific scan state
     969             :      */
     970       77822 :     indexstate->iss_RuntimeKeysReady = false;
     971       77822 :     indexstate->iss_RuntimeKeys = NULL;
     972       77822 :     indexstate->iss_NumRuntimeKeys = 0;
     973             : 
     974             :     /*
     975             :      * build the index scan keys from the index qualification
     976             :      */
     977      155644 :     ExecIndexBuildScanKeys((PlanState *) indexstate,
     978             :                            indexstate->iss_RelationDesc,
     979             :                            node->indexqual,
     980             :                            false,
     981       77822 :                            &indexstate->iss_ScanKeys,
     982             :                            &indexstate->iss_NumScanKeys,
     983             :                            &indexstate->iss_RuntimeKeys,
     984             :                            &indexstate->iss_NumRuntimeKeys,
     985             :                            NULL,    /* no ArrayKeys */
     986             :                            NULL);
     987             : 
     988             :     /*
     989             :      * any ORDER BY exprs have to be turned into scankeys in the same way
     990             :      */
     991      155644 :     ExecIndexBuildScanKeys((PlanState *) indexstate,
     992             :                            indexstate->iss_RelationDesc,
     993             :                            node->indexorderby,
     994             :                            true,
     995       77822 :                            &indexstate->iss_OrderByKeys,
     996             :                            &indexstate->iss_NumOrderByKeys,
     997             :                            &indexstate->iss_RuntimeKeys,
     998             :                            &indexstate->iss_NumRuntimeKeys,
     999             :                            NULL,    /* no ArrayKeys */
    1000             :                            NULL);
    1001             : 
    1002             :     /* Initialize sort support, if we need to re-check ORDER BY exprs */
    1003       77822 :     if (indexstate->iss_NumOrderByKeys > 0)
    1004             :     {
    1005          20 :         int         numOrderByKeys = indexstate->iss_NumOrderByKeys;
    1006             :         int         i;
    1007             :         ListCell   *lco;
    1008             :         ListCell   *lcx;
    1009             : 
    1010             :         /*
    1011             :          * Prepare sort support, and look up the data type for each ORDER BY
    1012             :          * expression.
    1013             :          */
    1014             :         Assert(numOrderByKeys == list_length(node->indexorderbyops));
    1015             :         Assert(numOrderByKeys == list_length(node->indexorderbyorig));
    1016          20 :         indexstate->iss_SortSupport = (SortSupportData *)
    1017          20 :             palloc0(numOrderByKeys * sizeof(SortSupportData));
    1018          20 :         indexstate->iss_OrderByTypByVals = (bool *)
    1019          20 :             palloc(numOrderByKeys * sizeof(bool));
    1020          20 :         indexstate->iss_OrderByTypLens = (int16 *)
    1021          20 :             palloc(numOrderByKeys * sizeof(int16));
    1022          20 :         i = 0;
    1023          40 :         forboth(lco, node->indexorderbyops, lcx, node->indexorderbyorig)
    1024             :         {
    1025          20 :             Oid         orderbyop = lfirst_oid(lco);
    1026          20 :             Node       *orderbyexpr = (Node *) lfirst(lcx);
    1027          20 :             Oid         orderbyType = exprType(orderbyexpr);
    1028          20 :             Oid         orderbyColl = exprCollation(orderbyexpr);
    1029          20 :             SortSupport orderbysort = &indexstate->iss_SortSupport[i];
    1030             : 
    1031             :             /* Initialize sort support */
    1032          20 :             orderbysort->ssup_cxt = CurrentMemoryContext;
    1033          20 :             orderbysort->ssup_collation = orderbyColl;
    1034             :             /* See cmp_orderbyvals() comments on NULLS LAST */
    1035          20 :             orderbysort->ssup_nulls_first = false;
    1036             :             /* ssup_attno is unused here and elsewhere */
    1037          20 :             orderbysort->ssup_attno = 0;
    1038             :             /* No abbreviation */
    1039          20 :             orderbysort->abbreviate = false;
    1040          20 :             PrepareSortSupportFromOrderingOp(orderbyop, orderbysort);
    1041             : 
    1042          40 :             get_typlenbyval(orderbyType,
    1043          20 :                             &indexstate->iss_OrderByTypLens[i],
    1044          20 :                             &indexstate->iss_OrderByTypByVals[i]);
    1045          20 :             i++;
    1046             :         }
    1047             : 
    1048             :         /* allocate arrays to hold the re-calculated distances */
    1049          20 :         indexstate->iss_OrderByValues = (Datum *)
    1050          20 :             palloc(numOrderByKeys * sizeof(Datum));
    1051          20 :         indexstate->iss_OrderByNulls = (bool *)
    1052          20 :             palloc(numOrderByKeys * sizeof(bool));
    1053             : 
    1054             :         /* and initialize the reorder queue */
    1055          20 :         indexstate->iss_ReorderQueue = pairingheap_allocate(reorderqueue_cmp,
    1056             :                                                             indexstate);
    1057             :     }
    1058             : 
    1059             :     /*
    1060             :      * If we have runtime keys, we need an ExprContext to evaluate them. The
    1061             :      * node's standard context won't do because we want to reset that context
    1062             :      * for every tuple.  So, build another context just like the other one...
    1063             :      * -tgl 7/11/00
    1064             :      */
    1065       77822 :     if (indexstate->iss_NumRuntimeKeys != 0)
    1066             :     {
    1067       29220 :         ExprContext *stdecontext = indexstate->ss.ps.ps_ExprContext;
    1068             : 
    1069       29220 :         ExecAssignExprContext(estate, &indexstate->ss.ps);
    1070       29220 :         indexstate->iss_RuntimeContext = indexstate->ss.ps.ps_ExprContext;
    1071       29220 :         indexstate->ss.ps.ps_ExprContext = stdecontext;
    1072             :     }
    1073             :     else
    1074             :     {
    1075       48602 :         indexstate->iss_RuntimeContext = NULL;
    1076             :     }
    1077             : 
    1078             :     /*
    1079             :      * all done.
    1080             :      */
    1081       77822 :     return indexstate;
    1082             : }
    1083             : 
    1084             : 
    1085             : /*
    1086             :  * ExecIndexBuildScanKeys
    1087             :  *      Build the index scan keys from the index qualification expressions
    1088             :  *
    1089             :  * The index quals are passed to the index AM in the form of a ScanKey array.
    1090             :  * This routine sets up the ScanKeys, fills in all constant fields of the
    1091             :  * ScanKeys, and prepares information about the keys that have non-constant
    1092             :  * comparison values.  We divide index qual expressions into five types:
    1093             :  *
    1094             :  * 1. Simple operator with constant comparison value ("indexkey op constant").
    1095             :  * For these, we just fill in a ScanKey containing the constant value.
    1096             :  *
    1097             :  * 2. Simple operator with non-constant value ("indexkey op expression").
    1098             :  * For these, we create a ScanKey with everything filled in except the
    1099             :  * expression value, and set up an IndexRuntimeKeyInfo struct to drive
    1100             :  * evaluation of the expression at the right times.
    1101             :  *
    1102             :  * 3. RowCompareExpr ("(indexkey, indexkey, ...) op (expr, expr, ...)").
    1103             :  * For these, we create a header ScanKey plus a subsidiary ScanKey array,
    1104             :  * as specified in access/skey.h.  The elements of the row comparison
    1105             :  * can have either constant or non-constant comparison values.
    1106             :  *
    1107             :  * 4. ScalarArrayOpExpr ("indexkey op ANY (array-expression)").  If the index
    1108             :  * supports amsearcharray, we handle these the same as simple operators,
    1109             :  * setting the SK_SEARCHARRAY flag to tell the AM to handle them.  Otherwise,
    1110             :  * we create a ScanKey with everything filled in except the comparison value,
    1111             :  * and set up an IndexArrayKeyInfo struct to drive processing of the qual.
    1112             :  * (Note that if we use an IndexArrayKeyInfo struct, the array expression is
    1113             :  * always treated as requiring runtime evaluation, even if it's a constant.)
    1114             :  *
    1115             :  * 5. NullTest ("indexkey IS NULL/IS NOT NULL").  We just fill in the
    1116             :  * ScanKey properly.
    1117             :  *
    1118             :  * This code is also used to prepare ORDER BY expressions for amcanorderbyop
    1119             :  * indexes.  The behavior is exactly the same, except that we have to look up
    1120             :  * the operator differently.  Note that only cases 1 and 2 are currently
    1121             :  * possible for ORDER BY.
    1122             :  *
    1123             :  * Input params are:
    1124             :  *
    1125             :  * planstate: executor state node we are working for
    1126             :  * index: the index we are building scan keys for
    1127             :  * quals: indexquals (or indexorderbys) expressions
    1128             :  * isorderby: true if processing ORDER BY exprs, false if processing quals
    1129             :  * *runtimeKeys: ptr to pre-existing IndexRuntimeKeyInfos, or NULL if none
    1130             :  * *numRuntimeKeys: number of pre-existing runtime keys
    1131             :  *
    1132             :  * Output params are:
    1133             :  *
    1134             :  * *scanKeys: receives ptr to array of ScanKeys
    1135             :  * *numScanKeys: receives number of scankeys
    1136             :  * *runtimeKeys: receives ptr to array of IndexRuntimeKeyInfos, or NULL if none
    1137             :  * *numRuntimeKeys: receives number of runtime keys
    1138             :  * *arrayKeys: receives ptr to array of IndexArrayKeyInfos, or NULL if none
    1139             :  * *numArrayKeys: receives number of array keys
    1140             :  *
    1141             :  * Caller may pass NULL for arrayKeys and numArrayKeys to indicate that
    1142             :  * IndexArrayKeyInfos are not supported.
    1143             :  */
    1144             : void
    1145      188784 : ExecIndexBuildScanKeys(PlanState *planstate, Relation index,
    1146             :                        List *quals, bool isorderby,
    1147             :                        ScanKey *scanKeys, int *numScanKeys,
    1148             :                        IndexRuntimeKeyInfo **runtimeKeys, int *numRuntimeKeys,
    1149             :                        IndexArrayKeyInfo **arrayKeys, int *numArrayKeys)
    1150             : {
    1151             :     ListCell   *qual_cell;
    1152             :     ScanKey     scan_keys;
    1153             :     IndexRuntimeKeyInfo *runtime_keys;
    1154             :     IndexArrayKeyInfo *array_keys;
    1155             :     int         n_scan_keys;
    1156             :     int         n_runtime_keys;
    1157             :     int         max_runtime_keys;
    1158             :     int         n_array_keys;
    1159             :     int         j;
    1160             : 
    1161             :     /* Allocate array for ScanKey structs: one per qual */
    1162      188784 :     n_scan_keys = list_length(quals);
    1163      188784 :     scan_keys = (ScanKey) palloc(n_scan_keys * sizeof(ScanKeyData));
    1164             : 
    1165             :     /*
    1166             :      * runtime_keys array is dynamically resized as needed.  We handle it this
    1167             :      * way so that the same runtime keys array can be shared between
    1168             :      * indexquals and indexorderbys, which will be processed in separate calls
    1169             :      * of this function.  Caller must be sure to pass in NULL/0 for first
    1170             :      * call.
    1171             :      */
    1172      188784 :     runtime_keys = *runtimeKeys;
    1173      188784 :     n_runtime_keys = max_runtime_keys = *numRuntimeKeys;
    1174             : 
    1175             :     /* Allocate array_keys as large as it could possibly need to be */
    1176      188784 :     array_keys = (IndexArrayKeyInfo *)
    1177      188784 :         palloc0(n_scan_keys * sizeof(IndexArrayKeyInfo));
    1178      188784 :     n_array_keys = 0;
    1179             : 
    1180             :     /*
    1181             :      * for each opclause in the given qual, convert the opclause into a single
    1182             :      * scan key
    1183             :      */
    1184      188784 :     j = 0;
    1185      308622 :     foreach(qual_cell, quals)
    1186             :     {
    1187      119838 :         Expr       *clause = (Expr *) lfirst(qual_cell);
    1188      119838 :         ScanKey     this_scan_key = &scan_keys[j++];
    1189             :         Oid         opno;       /* operator's OID */
    1190             :         RegProcedure opfuncid;  /* operator proc id used in scan */
    1191             :         Oid         opfamily;   /* opfamily of index column */
    1192             :         int         op_strategy;    /* operator's strategy number */
    1193             :         Oid         op_lefttype;    /* operator's declared input types */
    1194             :         Oid         op_righttype;
    1195             :         Expr       *leftop;     /* expr on lhs of operator */
    1196             :         Expr       *rightop;    /* expr on rhs ... */
    1197             :         AttrNumber  varattno;   /* att number used in scan */
    1198             :         int         indnkeyatts;
    1199             : 
    1200      119838 :         indnkeyatts = IndexRelationGetNumberOfKeyAttributes(index);
    1201      119838 :         if (IsA(clause, OpExpr))
    1202             :         {
    1203             :             /* indexkey op const or indexkey op expression */
    1204      119054 :             int         flags = 0;
    1205             :             Datum       scanvalue;
    1206             : 
    1207      119054 :             opno = ((OpExpr *) clause)->opno;
    1208      119054 :             opfuncid = ((OpExpr *) clause)->opfuncid;
    1209             : 
    1210             :             /*
    1211             :              * leftop should be the index key Var, possibly relabeled
    1212             :              */
    1213      119054 :             leftop = (Expr *) get_leftop(clause);
    1214             : 
    1215      119054 :             if (leftop && IsA(leftop, RelabelType))
    1216           0 :                 leftop = ((RelabelType *) leftop)->arg;
    1217             : 
    1218             :             Assert(leftop != NULL);
    1219             : 
    1220      238108 :             if (!(IsA(leftop, Var) &&
    1221      119054 :                   ((Var *) leftop)->varno == INDEX_VAR))
    1222           0 :                 elog(ERROR, "indexqual doesn't have key on left side");
    1223             : 
    1224      119054 :             varattno = ((Var *) leftop)->varattno;
    1225      119054 :             if (varattno < 1 || varattno > indnkeyatts)
    1226           0 :                 elog(ERROR, "bogus index qualification");
    1227             : 
    1228             :             /*
    1229             :              * We have to look up the operator's strategy number.  This
    1230             :              * provides a cross-check that the operator does match the index.
    1231             :              */
    1232      119054 :             opfamily = index->rd_opfamily[varattno - 1];
    1233             : 
    1234      119054 :             get_op_opfamily_properties(opno, opfamily, isorderby,
    1235             :                                        &op_strategy,
    1236             :                                        &op_lefttype,
    1237             :                                        &op_righttype);
    1238             : 
    1239      119054 :             if (isorderby)
    1240         112 :                 flags |= SK_ORDER_BY;
    1241             : 
    1242             :             /*
    1243             :              * rightop is the constant or variable comparison value
    1244             :              */
    1245      119054 :             rightop = (Expr *) get_rightop(clause);
    1246             : 
    1247      119054 :             if (rightop && IsA(rightop, RelabelType))
    1248         314 :                 rightop = ((RelabelType *) rightop)->arg;
    1249             : 
    1250             :             Assert(rightop != NULL);
    1251             : 
    1252      119054 :             if (IsA(rightop, Const))
    1253             :             {
    1254             :                 /* OK, simple constant comparison value */
    1255       83514 :                 scanvalue = ((Const *) rightop)->constvalue;
    1256       83514 :                 if (((Const *) rightop)->constisnull)
    1257           0 :                     flags |= SK_ISNULL;
    1258             :             }
    1259             :             else
    1260             :             {
    1261             :                 /* Need to treat this one as a runtime key */
    1262       35540 :                 if (n_runtime_keys >= max_runtime_keys)
    1263             :                 {
    1264       31450 :                     if (max_runtime_keys == 0)
    1265             :                     {
    1266       31446 :                         max_runtime_keys = 8;
    1267       31446 :                         runtime_keys = (IndexRuntimeKeyInfo *)
    1268       31446 :                             palloc(max_runtime_keys * sizeof(IndexRuntimeKeyInfo));
    1269             :                     }
    1270             :                     else
    1271             :                     {
    1272           4 :                         max_runtime_keys *= 2;
    1273           4 :                         runtime_keys = (IndexRuntimeKeyInfo *)
    1274           4 :                             repalloc(runtime_keys, max_runtime_keys * sizeof(IndexRuntimeKeyInfo));
    1275             :                     }
    1276             :                 }
    1277       35540 :                 runtime_keys[n_runtime_keys].scan_key = this_scan_key;
    1278       71080 :                 runtime_keys[n_runtime_keys].key_expr =
    1279       35540 :                     ExecInitExpr(rightop, planstate);
    1280       71080 :                 runtime_keys[n_runtime_keys].key_toastable =
    1281       35540 :                     TypeIsToastable(op_righttype);
    1282       35540 :                 n_runtime_keys++;
    1283       35540 :                 scanvalue = (Datum) 0;
    1284             :             }
    1285             : 
    1286             :             /*
    1287             :              * initialize the scan key's fields appropriately
    1288             :              */
    1289      119054 :             ScanKeyEntryInitialize(this_scan_key,
    1290             :                                    flags,
    1291             :                                    varattno,    /* attribute number to scan */
    1292             :                                    op_strategy, /* op's strategy */
    1293             :                                    op_righttype,    /* strategy subtype */
    1294             :                                    ((OpExpr *) clause)->inputcollid, /* collation */
    1295             :                                    opfuncid,    /* reg proc to use */
    1296             :                                    scanvalue);  /* constant */
    1297             :         }
    1298         784 :         else if (IsA(clause, RowCompareExpr))
    1299             :         {
    1300             :             /* (indexkey, indexkey, ...) op (expression, expression, ...) */
    1301          24 :             RowCompareExpr *rc = (RowCompareExpr *) clause;
    1302             :             ScanKey     first_sub_key;
    1303             :             int         n_sub_key;
    1304             :             ListCell   *largs_cell;
    1305             :             ListCell   *rargs_cell;
    1306             :             ListCell   *opnos_cell;
    1307             :             ListCell   *collids_cell;
    1308             : 
    1309             :             Assert(!isorderby);
    1310             : 
    1311          24 :             first_sub_key = (ScanKey)
    1312          24 :                 palloc(list_length(rc->opnos) * sizeof(ScanKeyData));
    1313          24 :             n_sub_key = 0;
    1314             : 
    1315             :             /* Scan RowCompare columns and generate subsidiary ScanKey items */
    1316          72 :             forfour(largs_cell, rc->largs, rargs_cell, rc->rargs,
    1317             :                     opnos_cell, rc->opnos, collids_cell, rc->inputcollids)
    1318             :             {
    1319          48 :                 ScanKey     this_sub_key = &first_sub_key[n_sub_key];
    1320          48 :                 int         flags = SK_ROW_MEMBER;
    1321             :                 Datum       scanvalue;
    1322             :                 Oid         inputcollation;
    1323             : 
    1324          48 :                 leftop = (Expr *) lfirst(largs_cell);
    1325          48 :                 rightop = (Expr *) lfirst(rargs_cell);
    1326          48 :                 opno = lfirst_oid(opnos_cell);
    1327          48 :                 inputcollation = lfirst_oid(collids_cell);
    1328             : 
    1329             :                 /*
    1330             :                  * leftop should be the index key Var, possibly relabeled
    1331             :                  */
    1332          48 :                 if (leftop && IsA(leftop, RelabelType))
    1333           0 :                     leftop = ((RelabelType *) leftop)->arg;
    1334             : 
    1335             :                 Assert(leftop != NULL);
    1336             : 
    1337          96 :                 if (!(IsA(leftop, Var) &&
    1338          48 :                       ((Var *) leftop)->varno == INDEX_VAR))
    1339           0 :                     elog(ERROR, "indexqual doesn't have key on left side");
    1340             : 
    1341          48 :                 varattno = ((Var *) leftop)->varattno;
    1342             : 
    1343             :                 /*
    1344             :                  * We have to look up the operator's associated btree support
    1345             :                  * function
    1346             :                  */
    1347          48 :                 if (index->rd_rel->relam != BTREE_AM_OID ||
    1348          48 :                     varattno < 1 || varattno > indnkeyatts)
    1349           0 :                     elog(ERROR, "bogus RowCompare index qualification");
    1350          48 :                 opfamily = index->rd_opfamily[varattno - 1];
    1351             : 
    1352          48 :                 get_op_opfamily_properties(opno, opfamily, isorderby,
    1353             :                                            &op_strategy,
    1354             :                                            &op_lefttype,
    1355             :                                            &op_righttype);
    1356             : 
    1357          48 :                 if (op_strategy != rc->rctype)
    1358           0 :                     elog(ERROR, "RowCompare index qualification contains wrong operator");
    1359             : 
    1360          48 :                 opfuncid = get_opfamily_proc(opfamily,
    1361             :                                              op_lefttype,
    1362             :                                              op_righttype,
    1363             :                                              BTORDER_PROC);
    1364          48 :                 if (!RegProcedureIsValid(opfuncid))
    1365           0 :                     elog(ERROR, "missing support function %d(%u,%u) in opfamily %u",
    1366             :                          BTORDER_PROC, op_lefttype, op_righttype, opfamily);
    1367             : 
    1368             :                 /*
    1369             :                  * rightop is the constant or variable comparison value
    1370             :                  */
    1371          48 :                 if (rightop && IsA(rightop, RelabelType))
    1372           0 :                     rightop = ((RelabelType *) rightop)->arg;
    1373             : 
    1374             :                 Assert(rightop != NULL);
    1375             : 
    1376          48 :                 if (IsA(rightop, Const))
    1377             :                 {
    1378             :                     /* OK, simple constant comparison value */
    1379          48 :                     scanvalue = ((Const *) rightop)->constvalue;
    1380          48 :                     if (((Const *) rightop)->constisnull)
    1381           0 :                         flags |= SK_ISNULL;
    1382             :                 }
    1383             :                 else
    1384             :                 {
    1385             :                     /* Need to treat this one as a runtime key */
    1386           0 :                     if (n_runtime_keys >= max_runtime_keys)
    1387             :                     {
    1388           0 :                         if (max_runtime_keys == 0)
    1389             :                         {
    1390           0 :                             max_runtime_keys = 8;
    1391           0 :                             runtime_keys = (IndexRuntimeKeyInfo *)
    1392           0 :                                 palloc(max_runtime_keys * sizeof(IndexRuntimeKeyInfo));
    1393             :                         }
    1394             :                         else
    1395             :                         {
    1396           0 :                             max_runtime_keys *= 2;
    1397           0 :                             runtime_keys = (IndexRuntimeKeyInfo *)
    1398           0 :                                 repalloc(runtime_keys, max_runtime_keys * sizeof(IndexRuntimeKeyInfo));
    1399             :                         }
    1400             :                     }
    1401           0 :                     runtime_keys[n_runtime_keys].scan_key = this_sub_key;
    1402           0 :                     runtime_keys[n_runtime_keys].key_expr =
    1403           0 :                         ExecInitExpr(rightop, planstate);
    1404           0 :                     runtime_keys[n_runtime_keys].key_toastable =
    1405           0 :                         TypeIsToastable(op_righttype);
    1406           0 :                     n_runtime_keys++;
    1407           0 :                     scanvalue = (Datum) 0;
    1408             :                 }
    1409             : 
    1410             :                 /*
    1411             :                  * initialize the subsidiary scan key's fields appropriately
    1412             :                  */
    1413          48 :                 ScanKeyEntryInitialize(this_sub_key,
    1414             :                                        flags,
    1415             :                                        varattno,    /* attribute number */
    1416             :                                        op_strategy, /* op's strategy */
    1417             :                                        op_righttype,    /* strategy subtype */
    1418             :                                        inputcollation,  /* collation */
    1419             :                                        opfuncid,    /* reg proc to use */
    1420             :                                        scanvalue);  /* constant */
    1421          48 :                 n_sub_key++;
    1422             :             }
    1423             : 
    1424             :             /* Mark the last subsidiary scankey correctly */
    1425          24 :             first_sub_key[n_sub_key - 1].sk_flags |= SK_ROW_END;
    1426             : 
    1427             :             /*
    1428             :              * We don't use ScanKeyEntryInitialize for the header because it
    1429             :              * isn't going to contain a valid sk_func pointer.
    1430             :              */
    1431          24 :             MemSet(this_scan_key, 0, sizeof(ScanKeyData));
    1432          24 :             this_scan_key->sk_flags = SK_ROW_HEADER;
    1433          24 :             this_scan_key->sk_attno = first_sub_key->sk_attno;
    1434          24 :             this_scan_key->sk_strategy = rc->rctype;
    1435             :             /* sk_subtype, sk_collation, sk_func not used in a header */
    1436          24 :             this_scan_key->sk_argument = PointerGetDatum(first_sub_key);
    1437             :         }
    1438         760 :         else if (IsA(clause, ScalarArrayOpExpr))
    1439             :         {
    1440             :             /* indexkey op ANY (array-expression) */
    1441         226 :             ScalarArrayOpExpr *saop = (ScalarArrayOpExpr *) clause;
    1442         226 :             int         flags = 0;
    1443             :             Datum       scanvalue;
    1444             : 
    1445             :             Assert(!isorderby);
    1446             : 
    1447             :             Assert(saop->useOr);
    1448         226 :             opno = saop->opno;
    1449         226 :             opfuncid = saop->opfuncid;
    1450             : 
    1451             :             /*
    1452             :              * leftop should be the index key Var, possibly relabeled
    1453             :              */
    1454         226 :             leftop = (Expr *) linitial(saop->args);
    1455             : 
    1456         226 :             if (leftop && IsA(leftop, RelabelType))
    1457           0 :                 leftop = ((RelabelType *) leftop)->arg;
    1458             : 
    1459             :             Assert(leftop != NULL);
    1460             : 
    1461         452 :             if (!(IsA(leftop, Var) &&
    1462         226 :                   ((Var *) leftop)->varno == INDEX_VAR))
    1463           0 :                 elog(ERROR, "indexqual doesn't have key on left side");
    1464             : 
    1465         226 :             varattno = ((Var *) leftop)->varattno;
    1466         226 :             if (varattno < 1 || varattno > indnkeyatts)
    1467           0 :                 elog(ERROR, "bogus index qualification");
    1468             : 
    1469             :             /*
    1470             :              * We have to look up the operator's strategy number.  This
    1471             :              * provides a cross-check that the operator does match the index.
    1472             :              */
    1473         226 :             opfamily = index->rd_opfamily[varattno - 1];
    1474             : 
    1475         226 :             get_op_opfamily_properties(opno, opfamily, isorderby,
    1476             :                                        &op_strategy,
    1477             :                                        &op_lefttype,
    1478             :                                        &op_righttype);
    1479             : 
    1480             :             /*
    1481             :              * rightop is the constant or variable array value
    1482             :              */
    1483         226 :             rightop = (Expr *) lsecond(saop->args);
    1484             : 
    1485         226 :             if (rightop && IsA(rightop, RelabelType))
    1486           0 :                 rightop = ((RelabelType *) rightop)->arg;
    1487             : 
    1488             :             Assert(rightop != NULL);
    1489             : 
    1490         226 :             if (index->rd_indam->amsearcharray)
    1491             :             {
    1492             :                 /* Index AM will handle this like a simple operator */
    1493         218 :                 flags |= SK_SEARCHARRAY;
    1494         218 :                 if (IsA(rightop, Const))
    1495             :                 {
    1496             :                     /* OK, simple constant comparison value */
    1497         218 :                     scanvalue = ((Const *) rightop)->constvalue;
    1498         218 :                     if (((Const *) rightop)->constisnull)
    1499           0 :                         flags |= SK_ISNULL;
    1500             :                 }
    1501             :                 else
    1502             :                 {
    1503             :                     /* Need to treat this one as a runtime key */
    1504           0 :                     if (n_runtime_keys >= max_runtime_keys)
    1505             :                     {
    1506           0 :                         if (max_runtime_keys == 0)
    1507             :                         {
    1508           0 :                             max_runtime_keys = 8;
    1509           0 :                             runtime_keys = (IndexRuntimeKeyInfo *)
    1510           0 :                                 palloc(max_runtime_keys * sizeof(IndexRuntimeKeyInfo));
    1511             :                         }
    1512             :                         else
    1513             :                         {
    1514           0 :                             max_runtime_keys *= 2;
    1515           0 :                             runtime_keys = (IndexRuntimeKeyInfo *)
    1516           0 :                                 repalloc(runtime_keys, max_runtime_keys * sizeof(IndexRuntimeKeyInfo));
    1517             :                         }
    1518             :                     }
    1519           0 :                     runtime_keys[n_runtime_keys].scan_key = this_scan_key;
    1520           0 :                     runtime_keys[n_runtime_keys].key_expr =
    1521           0 :                         ExecInitExpr(rightop, planstate);
    1522             : 
    1523             :                     /*
    1524             :                      * Careful here: the runtime expression is not of
    1525             :                      * op_righttype, but rather is an array of same; so
    1526             :                      * TypeIsToastable() isn't helpful.  However, we can
    1527             :                      * assume that all array types are toastable.
    1528             :                      */
    1529           0 :                     runtime_keys[n_runtime_keys].key_toastable = true;
    1530           0 :                     n_runtime_keys++;
    1531           0 :                     scanvalue = (Datum) 0;
    1532             :                 }
    1533             :             }
    1534             :             else
    1535             :             {
    1536             :                 /* Executor has to expand the array value */
    1537           8 :                 array_keys[n_array_keys].scan_key = this_scan_key;
    1538          16 :                 array_keys[n_array_keys].array_expr =
    1539           8 :                     ExecInitExpr(rightop, planstate);
    1540             :                 /* the remaining fields were zeroed by palloc0 */
    1541           8 :                 n_array_keys++;
    1542           8 :                 scanvalue = (Datum) 0;
    1543             :             }
    1544             : 
    1545             :             /*
    1546             :              * initialize the scan key's fields appropriately
    1547             :              */
    1548         226 :             ScanKeyEntryInitialize(this_scan_key,
    1549             :                                    flags,
    1550             :                                    varattno,    /* attribute number to scan */
    1551             :                                    op_strategy, /* op's strategy */
    1552             :                                    op_righttype,    /* strategy subtype */
    1553             :                                    saop->inputcollid,    /* collation */
    1554             :                                    opfuncid,    /* reg proc to use */
    1555             :                                    scanvalue);  /* constant */
    1556             :         }
    1557         534 :         else if (IsA(clause, NullTest))
    1558             :         {
    1559             :             /* indexkey IS NULL or indexkey IS NOT NULL */
    1560         534 :             NullTest   *ntest = (NullTest *) clause;
    1561             :             int         flags;
    1562             : 
    1563             :             Assert(!isorderby);
    1564             : 
    1565             :             /*
    1566             :              * argument should be the index key Var, possibly relabeled
    1567             :              */
    1568         534 :             leftop = ntest->arg;
    1569             : 
    1570         534 :             if (leftop && IsA(leftop, RelabelType))
    1571           0 :                 leftop = ((RelabelType *) leftop)->arg;
    1572             : 
    1573             :             Assert(leftop != NULL);
    1574             : 
    1575        1068 :             if (!(IsA(leftop, Var) &&
    1576         534 :                   ((Var *) leftop)->varno == INDEX_VAR))
    1577           0 :                 elog(ERROR, "NullTest indexqual has wrong key");
    1578             : 
    1579         534 :             varattno = ((Var *) leftop)->varattno;
    1580             : 
    1581             :             /*
    1582             :              * initialize the scan key's fields appropriately
    1583             :              */
    1584         534 :             switch (ntest->nulltesttype)
    1585             :             {
    1586             :                 case IS_NULL:
    1587         110 :                     flags = SK_ISNULL | SK_SEARCHNULL;
    1588         110 :                     break;
    1589             :                 case IS_NOT_NULL:
    1590         424 :                     flags = SK_ISNULL | SK_SEARCHNOTNULL;
    1591         424 :                     break;
    1592             :                 default:
    1593           0 :                     elog(ERROR, "unrecognized nulltesttype: %d",
    1594             :                          (int) ntest->nulltesttype);
    1595             :                     flags = 0;  /* keep compiler quiet */
    1596             :                     break;
    1597             :             }
    1598             : 
    1599         534 :             ScanKeyEntryInitialize(this_scan_key,
    1600             :                                    flags,
    1601             :                                    varattno,    /* attribute number to scan */
    1602             :                                    InvalidStrategy, /* no strategy */
    1603             :                                    InvalidOid,  /* no strategy subtype */
    1604             :                                    InvalidOid,  /* no collation */
    1605             :                                    InvalidOid,  /* no reg proc for this */
    1606             :                                    (Datum) 0);  /* constant */
    1607             :         }
    1608             :         else
    1609           0 :             elog(ERROR, "unsupported indexqual type: %d",
    1610             :                  (int) nodeTag(clause));
    1611             :     }
    1612             : 
    1613             :     Assert(n_runtime_keys <= max_runtime_keys);
    1614             : 
    1615             :     /* Get rid of any unused arrays */
    1616      188784 :     if (n_array_keys == 0)
    1617             :     {
    1618      188776 :         pfree(array_keys);
    1619      188776 :         array_keys = NULL;
    1620             :     }
    1621             : 
    1622             :     /*
    1623             :      * Return info to our caller.
    1624             :      */
    1625      188784 :     *scanKeys = scan_keys;
    1626      188784 :     *numScanKeys = n_scan_keys;
    1627      188784 :     *runtimeKeys = runtime_keys;
    1628      188784 :     *numRuntimeKeys = n_runtime_keys;
    1629      188784 :     if (arrayKeys)
    1630             :     {
    1631       18312 :         *arrayKeys = array_keys;
    1632       18312 :         *numArrayKeys = n_array_keys;
    1633             :     }
    1634      170472 :     else if (n_array_keys != 0)
    1635           0 :         elog(ERROR, "ScalarArrayOpExpr index qual found where not allowed");
    1636      188784 : }
    1637             : 
    1638             : /* ----------------------------------------------------------------
    1639             :  *                      Parallel Scan Support
    1640             :  * ----------------------------------------------------------------
    1641             :  */
    1642             : 
    1643             : /* ----------------------------------------------------------------
    1644             :  *      ExecIndexScanEstimate
    1645             :  *
    1646             :  *      Compute the amount of space we'll need in the parallel
    1647             :  *      query DSM, and inform pcxt->estimator about our needs.
    1648             :  * ----------------------------------------------------------------
    1649             :  */
    1650             : void
    1651           8 : ExecIndexScanEstimate(IndexScanState *node,
    1652             :                       ParallelContext *pcxt)
    1653             : {
    1654           8 :     EState     *estate = node->ss.ps.state;
    1655             : 
    1656           8 :     node->iss_PscanLen = index_parallelscan_estimate(node->iss_RelationDesc,
    1657             :                                                      estate->es_snapshot);
    1658           8 :     shm_toc_estimate_chunk(&pcxt->estimator, node->iss_PscanLen);
    1659           8 :     shm_toc_estimate_keys(&pcxt->estimator, 1);
    1660           8 : }
    1661             : 
    1662             : /* ----------------------------------------------------------------
    1663             :  *      ExecIndexScanInitializeDSM
    1664             :  *
    1665             :  *      Set up a parallel index scan descriptor.
    1666             :  * ----------------------------------------------------------------
    1667             :  */
    1668             : void
    1669           8 : ExecIndexScanInitializeDSM(IndexScanState *node,
    1670             :                            ParallelContext *pcxt)
    1671             : {
    1672           8 :     EState     *estate = node->ss.ps.state;
    1673             :     ParallelIndexScanDesc piscan;
    1674             : 
    1675           8 :     piscan = shm_toc_allocate(pcxt->toc, node->iss_PscanLen);
    1676           8 :     index_parallelscan_initialize(node->ss.ss_currentRelation,
    1677             :                                   node->iss_RelationDesc,
    1678             :                                   estate->es_snapshot,
    1679             :                                   piscan);
    1680           8 :     shm_toc_insert(pcxt->toc, node->ss.ps.plan->plan_node_id, piscan);
    1681           8 :     node->iss_ScanDesc =
    1682           8 :         index_beginscan_parallel(node->ss.ss_currentRelation,
    1683             :                                  node->iss_RelationDesc,
    1684             :                                  node->iss_NumScanKeys,
    1685             :                                  node->iss_NumOrderByKeys,
    1686             :                                  piscan);
    1687             : 
    1688             :     /*
    1689             :      * If no run-time keys to calculate or they are ready, go ahead and pass
    1690             :      * the scankeys to the index AM.
    1691             :      */
    1692           8 :     if (node->iss_NumRuntimeKeys == 0 || node->iss_RuntimeKeysReady)
    1693          24 :         index_rescan(node->iss_ScanDesc,
    1694           8 :                      node->iss_ScanKeys, node->iss_NumScanKeys,
    1695           8 :                      node->iss_OrderByKeys, node->iss_NumOrderByKeys);
    1696           8 : }
    1697             : 
    1698             : /* ----------------------------------------------------------------
    1699             :  *      ExecIndexScanReInitializeDSM
    1700             :  *
    1701             :  *      Reset shared state before beginning a fresh scan.
    1702             :  * ----------------------------------------------------------------
    1703             :  */
    1704             : void
    1705           8 : ExecIndexScanReInitializeDSM(IndexScanState *node,
    1706             :                              ParallelContext *pcxt)
    1707             : {
    1708           8 :     index_parallelrescan(node->iss_ScanDesc);
    1709           8 : }
    1710             : 
    1711             : /* ----------------------------------------------------------------
    1712             :  *      ExecIndexScanInitializeWorker
    1713             :  *
    1714             :  *      Copy relevant information from TOC into planstate.
    1715             :  * ----------------------------------------------------------------
    1716             :  */
    1717             : void
    1718          64 : ExecIndexScanInitializeWorker(IndexScanState *node,
    1719             :                               ParallelWorkerContext *pwcxt)
    1720             : {
    1721             :     ParallelIndexScanDesc piscan;
    1722             : 
    1723          64 :     piscan = shm_toc_lookup(pwcxt->toc, node->ss.ps.plan->plan_node_id, false);
    1724          64 :     node->iss_ScanDesc =
    1725          64 :         index_beginscan_parallel(node->ss.ss_currentRelation,
    1726             :                                  node->iss_RelationDesc,
    1727             :                                  node->iss_NumScanKeys,
    1728             :                                  node->iss_NumOrderByKeys,
    1729             :                                  piscan);
    1730             : 
    1731             :     /*
    1732             :      * If no run-time keys to calculate or they are ready, go ahead and pass
    1733             :      * the scankeys to the index AM.
    1734             :      */
    1735          64 :     if (node->iss_NumRuntimeKeys == 0 || node->iss_RuntimeKeysReady)
    1736         192 :         index_rescan(node->iss_ScanDesc,
    1737          64 :                      node->iss_ScanKeys, node->iss_NumScanKeys,
    1738          64 :                      node->iss_OrderByKeys, node->iss_NumOrderByKeys);
    1739          64 : }

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