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Diffstat (limited to '')
| -rw-r--r-- | src/backend/executor/nodeIndexscan.c | 1747 |
1 files changed, 1747 insertions, 0 deletions
diff --git a/src/backend/executor/nodeIndexscan.c b/src/backend/executor/nodeIndexscan.c new file mode 100644 index 0000000..add29b3 --- /dev/null +++ b/src/backend/executor/nodeIndexscan.c @@ -0,0 +1,1747 @@ +/*------------------------------------------------------------------------- + * + * nodeIndexscan.c + * Routines to support indexed scans of relations + * + * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group + * Portions Copyright (c) 1994, Regents of the University of California + * + * + * IDENTIFICATION + * src/backend/executor/nodeIndexscan.c + * + *------------------------------------------------------------------------- + */ +/* + * INTERFACE ROUTINES + * ExecIndexScan scans a relation using an index + * IndexNext retrieve next tuple using index + * IndexNextWithReorder same, but recheck ORDER BY expressions + * ExecInitIndexScan creates and initializes state info. + * ExecReScanIndexScan rescans the indexed relation. + * ExecEndIndexScan releases all storage. + * ExecIndexMarkPos marks scan position. + * ExecIndexRestrPos restores scan position. + * ExecIndexScanEstimate estimates DSM space needed for parallel index scan + * ExecIndexScanInitializeDSM initialize DSM for parallel indexscan + * ExecIndexScanReInitializeDSM reinitialize DSM for fresh scan + * ExecIndexScanInitializeWorker attach to DSM info in parallel worker + */ +#include "postgres.h" + +#include "access/nbtree.h" +#include "access/relscan.h" +#include "access/tableam.h" +#include "catalog/pg_am.h" +#include "executor/execdebug.h" +#include "executor/nodeIndexscan.h" +#include "lib/pairingheap.h" +#include "miscadmin.h" +#include "nodes/nodeFuncs.h" +#include "utils/array.h" +#include "utils/datum.h" +#include "utils/lsyscache.h" +#include "utils/memutils.h" +#include "utils/rel.h" + +/* + * When an ordering operator is used, tuples fetched from the index that + * need to be reordered are queued in a pairing heap, as ReorderTuples. + */ +typedef struct +{ + pairingheap_node ph_node; + HeapTuple htup; + Datum *orderbyvals; + bool *orderbynulls; +} ReorderTuple; + +static TupleTableSlot *IndexNext(IndexScanState *node); +static TupleTableSlot *IndexNextWithReorder(IndexScanState *node); +static void EvalOrderByExpressions(IndexScanState *node, ExprContext *econtext); +static bool IndexRecheck(IndexScanState *node, TupleTableSlot *slot); +static int cmp_orderbyvals(const Datum *adist, const bool *anulls, + const Datum *bdist, const bool *bnulls, + IndexScanState *node); +static int reorderqueue_cmp(const pairingheap_node *a, + const pairingheap_node *b, void *arg); +static void reorderqueue_push(IndexScanState *node, TupleTableSlot *slot, + Datum *orderbyvals, bool *orderbynulls); +static HeapTuple reorderqueue_pop(IndexScanState *node); + + +/* ---------------------------------------------------------------- + * IndexNext + * + * Retrieve a tuple from the IndexScan node's currentRelation + * using the index specified in the IndexScanState information. + * ---------------------------------------------------------------- + */ +static TupleTableSlot * +IndexNext(IndexScanState *node) +{ + EState *estate; + ExprContext *econtext; + ScanDirection direction; + IndexScanDesc scandesc; + TupleTableSlot *slot; + + /* + * extract necessary information from index scan node + */ + estate = node->ss.ps.state; + direction = estate->es_direction; + /* flip direction if this is an overall backward scan */ + if (ScanDirectionIsBackward(((IndexScan *) node->ss.ps.plan)->indexorderdir)) + { + if (ScanDirectionIsForward(direction)) + direction = BackwardScanDirection; + else if (ScanDirectionIsBackward(direction)) + direction = ForwardScanDirection; + } + scandesc = node->iss_ScanDesc; + econtext = node->ss.ps.ps_ExprContext; + slot = node->ss.ss_ScanTupleSlot; + + if (scandesc == NULL) + { + /* + * We reach here if the index scan is not parallel, or if we're + * serially executing an index scan that was planned to be parallel. + */ + scandesc = index_beginscan(node->ss.ss_currentRelation, + node->iss_RelationDesc, + estate->es_snapshot, + node->iss_NumScanKeys, + node->iss_NumOrderByKeys); + + node->iss_ScanDesc = scandesc; + + /* + * If no run-time keys to calculate or they are ready, go ahead and + * pass the scankeys to the index AM. + */ + if (node->iss_NumRuntimeKeys == 0 || node->iss_RuntimeKeysReady) + index_rescan(scandesc, + node->iss_ScanKeys, node->iss_NumScanKeys, + node->iss_OrderByKeys, node->iss_NumOrderByKeys); + } + + /* + * ok, now that we have what we need, fetch the next tuple. + */ + while (index_getnext_slot(scandesc, direction, slot)) + { + CHECK_FOR_INTERRUPTS(); + + /* + * If the index was lossy, we have to recheck the index quals using + * the fetched tuple. + */ + if (scandesc->xs_recheck) + { + econtext->ecxt_scantuple = slot; + if (!ExecQualAndReset(node->indexqualorig, econtext)) + { + /* Fails recheck, so drop it and loop back for another */ + InstrCountFiltered2(node, 1); + continue; + } + } + + return slot; + } + + /* + * if we get here it means the index scan failed so we are at the end of + * the scan.. + */ + node->iss_ReachedEnd = true; + return ExecClearTuple(slot); +} + +/* ---------------------------------------------------------------- + * IndexNextWithReorder + * + * Like IndexNext, but this version can also re-check ORDER BY + * expressions, and reorder the tuples as necessary. + * ---------------------------------------------------------------- + */ +static TupleTableSlot * +IndexNextWithReorder(IndexScanState *node) +{ + EState *estate; + ExprContext *econtext; + IndexScanDesc scandesc; + TupleTableSlot *slot; + ReorderTuple *topmost = NULL; + bool was_exact; + Datum *lastfetched_vals; + bool *lastfetched_nulls; + int cmp; + + estate = node->ss.ps.state; + + /* + * Only forward scan is supported with reordering. Note: we can get away + * with just Asserting here because the system will not try to run the + * plan backwards if ExecSupportsBackwardScan() says it won't work. + * Currently, that is guaranteed because no index AMs support both + * amcanorderbyop and amcanbackward; if any ever do, + * ExecSupportsBackwardScan() will need to consider indexorderbys + * explicitly. + */ + Assert(!ScanDirectionIsBackward(((IndexScan *) node->ss.ps.plan)->indexorderdir)); + Assert(ScanDirectionIsForward(estate->es_direction)); + + scandesc = node->iss_ScanDesc; + econtext = node->ss.ps.ps_ExprContext; + slot = node->ss.ss_ScanTupleSlot; + + if (scandesc == NULL) + { + /* + * We reach here if the index scan is not parallel, or if we're + * serially executing an index scan that was planned to be parallel. + */ + scandesc = index_beginscan(node->ss.ss_currentRelation, + node->iss_RelationDesc, + estate->es_snapshot, + node->iss_NumScanKeys, + node->iss_NumOrderByKeys); + + node->iss_ScanDesc = scandesc; + + /* + * If no run-time keys to calculate or they are ready, go ahead and + * pass the scankeys to the index AM. + */ + if (node->iss_NumRuntimeKeys == 0 || node->iss_RuntimeKeysReady) + index_rescan(scandesc, + node->iss_ScanKeys, node->iss_NumScanKeys, + node->iss_OrderByKeys, node->iss_NumOrderByKeys); + } + + for (;;) + { + CHECK_FOR_INTERRUPTS(); + + /* + * Check the reorder queue first. If the topmost tuple in the queue + * has an ORDER BY value smaller than (or equal to) the value last + * returned by the index, we can return it now. + */ + if (!pairingheap_is_empty(node->iss_ReorderQueue)) + { + topmost = (ReorderTuple *) pairingheap_first(node->iss_ReorderQueue); + + if (node->iss_ReachedEnd || + cmp_orderbyvals(topmost->orderbyvals, + topmost->orderbynulls, + scandesc->xs_orderbyvals, + scandesc->xs_orderbynulls, + node) <= 0) + { + HeapTuple tuple; + + tuple = reorderqueue_pop(node); + + /* Pass 'true', as the tuple in the queue is a palloc'd copy */ + ExecForceStoreHeapTuple(tuple, slot, true); + return slot; + } + } + else if (node->iss_ReachedEnd) + { + /* Queue is empty, and no more tuples from index. We're done. */ + return ExecClearTuple(slot); + } + + /* + * Fetch next tuple from the index. + */ +next_indextuple: + if (!index_getnext_slot(scandesc, ForwardScanDirection, slot)) + { + /* + * No more tuples from the index. But we still need to drain any + * remaining tuples from the queue before we're done. + */ + node->iss_ReachedEnd = true; + continue; + } + + /* + * If the index was lossy, we have to recheck the index quals and + * ORDER BY expressions using the fetched tuple. + */ + if (scandesc->xs_recheck) + { + econtext->ecxt_scantuple = slot; + if (!ExecQualAndReset(node->indexqualorig, econtext)) + { + /* Fails recheck, so drop it and loop back for another */ + InstrCountFiltered2(node, 1); + /* allow this loop to be cancellable */ + CHECK_FOR_INTERRUPTS(); + goto next_indextuple; + } + } + + if (scandesc->xs_recheckorderby) + { + econtext->ecxt_scantuple = slot; + ResetExprContext(econtext); + EvalOrderByExpressions(node, econtext); + + /* + * Was the ORDER BY value returned by the index accurate? The + * recheck flag means that the index can return inaccurate values, + * but then again, the value returned for any particular tuple + * could also be exactly correct. Compare the value returned by + * the index with the recalculated value. (If the value returned + * by the index happened to be exact right, we can often avoid + * pushing the tuple to the queue, just to pop it back out again.) + */ + cmp = cmp_orderbyvals(node->iss_OrderByValues, + node->iss_OrderByNulls, + scandesc->xs_orderbyvals, + scandesc->xs_orderbynulls, + node); + if (cmp < 0) + elog(ERROR, "index returned tuples in wrong order"); + else if (cmp == 0) + was_exact = true; + else + was_exact = false; + lastfetched_vals = node->iss_OrderByValues; + lastfetched_nulls = node->iss_OrderByNulls; + } + else + { + was_exact = true; + lastfetched_vals = scandesc->xs_orderbyvals; + lastfetched_nulls = scandesc->xs_orderbynulls; + } + + /* + * Can we return this tuple immediately, or does it need to be pushed + * to the reorder queue? If the ORDER BY expression values returned + * by the index were inaccurate, we can't return it yet, because the + * next tuple from the index might need to come before this one. Also, + * we can't return it yet if there are any smaller tuples in the queue + * already. + */ + if (!was_exact || (topmost && cmp_orderbyvals(lastfetched_vals, + lastfetched_nulls, + topmost->orderbyvals, + topmost->orderbynulls, + node) > 0)) + { + /* Put this tuple to the queue */ + reorderqueue_push(node, slot, lastfetched_vals, lastfetched_nulls); + continue; + } + else + { + /* Can return this tuple immediately. */ + return slot; + } + } + + /* + * if we get here it means the index scan failed so we are at the end of + * the scan.. + */ + return ExecClearTuple(slot); +} + +/* + * Calculate the expressions in the ORDER BY clause, based on the heap tuple. + */ +static void +EvalOrderByExpressions(IndexScanState *node, ExprContext *econtext) +{ + int i; + ListCell *l; + MemoryContext oldContext; + + oldContext = MemoryContextSwitchTo(econtext->ecxt_per_tuple_memory); + + i = 0; + foreach(l, node->indexorderbyorig) + { + ExprState *orderby = (ExprState *) lfirst(l); + + node->iss_OrderByValues[i] = ExecEvalExpr(orderby, + econtext, + &node->iss_OrderByNulls[i]); + i++; + } + + MemoryContextSwitchTo(oldContext); +} + +/* + * IndexRecheck -- access method routine to recheck a tuple in EvalPlanQual + */ +static bool +IndexRecheck(IndexScanState *node, TupleTableSlot *slot) +{ + ExprContext *econtext; + + /* + * extract necessary information from index scan node + */ + econtext = node->ss.ps.ps_ExprContext; + + /* Does the tuple meet the indexqual condition? */ + econtext->ecxt_scantuple = slot; + return ExecQualAndReset(node->indexqualorig, econtext); +} + + +/* + * Compare ORDER BY expression values. + */ +static int +cmp_orderbyvals(const Datum *adist, const bool *anulls, + const Datum *bdist, const bool *bnulls, + IndexScanState *node) +{ + int i; + int result; + + for (i = 0; i < node->iss_NumOrderByKeys; i++) + { + SortSupport ssup = &node->iss_SortSupport[i]; + + /* + * Handle nulls. We only need to support NULLS LAST ordering, because + * match_pathkeys_to_index() doesn't consider indexorderby + * implementation otherwise. + */ + if (anulls[i] && !bnulls[i]) + return 1; + else if (!anulls[i] && bnulls[i]) + return -1; + else if (anulls[i] && bnulls[i]) + return 0; + + result = ssup->comparator(adist[i], bdist[i], ssup); + if (result != 0) + return result; + } + + return 0; +} + +/* + * Pairing heap provides getting topmost (greatest) element while KNN provides + * ascending sort. That's why we invert the sort order. + */ +static int +reorderqueue_cmp(const pairingheap_node *a, const pairingheap_node *b, + void *arg) +{ + ReorderTuple *rta = (ReorderTuple *) a; + ReorderTuple *rtb = (ReorderTuple *) b; + IndexScanState *node = (IndexScanState *) arg; + + /* exchange argument order to invert the sort order */ + return cmp_orderbyvals(rtb->orderbyvals, rtb->orderbynulls, + rta->orderbyvals, rta->orderbynulls, + node); +} + +/* + * Helper function to push a tuple to the reorder queue. + */ +static void +reorderqueue_push(IndexScanState *node, TupleTableSlot *slot, + Datum *orderbyvals, bool *orderbynulls) +{ + IndexScanDesc scandesc = node->iss_ScanDesc; + EState *estate = node->ss.ps.state; + MemoryContext oldContext = MemoryContextSwitchTo(estate->es_query_cxt); + ReorderTuple *rt; + int i; + + rt = (ReorderTuple *) palloc(sizeof(ReorderTuple)); + rt->htup = ExecCopySlotHeapTuple(slot); + rt->orderbyvals = + (Datum *) palloc(sizeof(Datum) * scandesc->numberOfOrderBys); + rt->orderbynulls = + (bool *) palloc(sizeof(bool) * scandesc->numberOfOrderBys); + for (i = 0; i < node->iss_NumOrderByKeys; i++) + { + if (!orderbynulls[i]) + rt->orderbyvals[i] = datumCopy(orderbyvals[i], + node->iss_OrderByTypByVals[i], + node->iss_OrderByTypLens[i]); + else + rt->orderbyvals[i] = (Datum) 0; + rt->orderbynulls[i] = orderbynulls[i]; + } + pairingheap_add(node->iss_ReorderQueue, &rt->ph_node); + + MemoryContextSwitchTo(oldContext); +} + +/* + * Helper function to pop the next tuple from the reorder queue. + */ +static HeapTuple +reorderqueue_pop(IndexScanState *node) +{ + HeapTuple result; + ReorderTuple *topmost; + int i; + + topmost = (ReorderTuple *) pairingheap_remove_first(node->iss_ReorderQueue); + + result = topmost->htup; + for (i = 0; i < node->iss_NumOrderByKeys; i++) + { + if (!node->iss_OrderByTypByVals[i] && !topmost->orderbynulls[i]) + pfree(DatumGetPointer(topmost->orderbyvals[i])); + } + pfree(topmost->orderbyvals); + pfree(topmost->orderbynulls); + pfree(topmost); + + return result; +} + + +/* ---------------------------------------------------------------- + * ExecIndexScan(node) + * ---------------------------------------------------------------- + */ +static TupleTableSlot * +ExecIndexScan(PlanState *pstate) +{ + IndexScanState *node = castNode(IndexScanState, pstate); + + /* + * If we have runtime keys and they've not already been set up, do it now. + */ + if (node->iss_NumRuntimeKeys != 0 && !node->iss_RuntimeKeysReady) + ExecReScan((PlanState *) node); + + if (node->iss_NumOrderByKeys > 0) + return ExecScan(&node->ss, + (ExecScanAccessMtd) IndexNextWithReorder, + (ExecScanRecheckMtd) IndexRecheck); + else + return ExecScan(&node->ss, + (ExecScanAccessMtd) IndexNext, + (ExecScanRecheckMtd) IndexRecheck); +} + +/* ---------------------------------------------------------------- + * ExecReScanIndexScan(node) + * + * Recalculates the values of any scan keys whose value depends on + * information known at runtime, then rescans the indexed relation. + * + * Updating the scan key was formerly done separately in + * ExecUpdateIndexScanKeys. Integrating it into ReScan makes + * rescans of indices and relations/general streams more uniform. + * ---------------------------------------------------------------- + */ +void +ExecReScanIndexScan(IndexScanState *node) +{ + /* + * If we are doing runtime key calculations (ie, any of the index key + * values weren't simple Consts), compute the new key values. But first, + * reset the context so we don't leak memory as each outer tuple is + * scanned. Note this assumes that we will recalculate *all* runtime keys + * on each call. + */ + if (node->iss_NumRuntimeKeys != 0) + { + ExprContext *econtext = node->iss_RuntimeContext; + + ResetExprContext(econtext); + ExecIndexEvalRuntimeKeys(econtext, + node->iss_RuntimeKeys, + node->iss_NumRuntimeKeys); + } + node->iss_RuntimeKeysReady = true; + + /* flush the reorder queue */ + if (node->iss_ReorderQueue) + { + HeapTuple tuple; + while (!pairingheap_is_empty(node->iss_ReorderQueue)) + { + tuple = reorderqueue_pop(node); + heap_freetuple(tuple); + } + } + + /* reset index scan */ + if (node->iss_ScanDesc) + index_rescan(node->iss_ScanDesc, + node->iss_ScanKeys, node->iss_NumScanKeys, + node->iss_OrderByKeys, node->iss_NumOrderByKeys); + node->iss_ReachedEnd = false; + + ExecScanReScan(&node->ss); +} + + +/* + * ExecIndexEvalRuntimeKeys + * Evaluate any runtime key values, and update the scankeys. + */ +void +ExecIndexEvalRuntimeKeys(ExprContext *econtext, + IndexRuntimeKeyInfo *runtimeKeys, int numRuntimeKeys) +{ + int j; + MemoryContext oldContext; + + /* We want to keep the key values in per-tuple memory */ + oldContext = MemoryContextSwitchTo(econtext->ecxt_per_tuple_memory); + + for (j = 0; j < numRuntimeKeys; j++) + { + ScanKey scan_key = runtimeKeys[j].scan_key; + ExprState *key_expr = runtimeKeys[j].key_expr; + Datum scanvalue; + bool isNull; + + /* + * For each run-time key, extract the run-time expression and evaluate + * it with respect to the current context. We then stick the result + * into the proper scan key. + * + * Note: the result of the eval could be a pass-by-ref value that's + * stored in some outer scan's tuple, not in + * econtext->ecxt_per_tuple_memory. We assume that the outer tuple + * will stay put throughout our scan. If this is wrong, we could copy + * the result into our context explicitly, but I think that's not + * necessary. + * + * It's also entirely possible that the result of the eval is a + * toasted value. In this case we should forcibly detoast it, to + * avoid repeat detoastings each time the value is examined by an + * index support function. + */ + scanvalue = ExecEvalExpr(key_expr, + econtext, + &isNull); + if (isNull) + { + scan_key->sk_argument = scanvalue; + scan_key->sk_flags |= SK_ISNULL; + } + else + { + if (runtimeKeys[j].key_toastable) + scanvalue = PointerGetDatum(PG_DETOAST_DATUM(scanvalue)); + scan_key->sk_argument = scanvalue; + scan_key->sk_flags &= ~SK_ISNULL; + } + } + + MemoryContextSwitchTo(oldContext); +} + +/* + * ExecIndexEvalArrayKeys + * Evaluate any array key values, and set up to iterate through arrays. + * + * Returns true if there are array elements to consider; false means there + * is at least one null or empty array, so no match is possible. On true + * result, the scankeys are initialized with the first elements of the arrays. + */ +bool +ExecIndexEvalArrayKeys(ExprContext *econtext, + IndexArrayKeyInfo *arrayKeys, int numArrayKeys) +{ + bool result = true; + int j; + MemoryContext oldContext; + + /* We want to keep the arrays in per-tuple memory */ + oldContext = MemoryContextSwitchTo(econtext->ecxt_per_tuple_memory); + + for (j = 0; j < numArrayKeys; j++) + { + ScanKey scan_key = arrayKeys[j].scan_key; + ExprState *array_expr = arrayKeys[j].array_expr; + Datum arraydatum; + bool isNull; + ArrayType *arrayval; + int16 elmlen; + bool elmbyval; + char elmalign; + int num_elems; + Datum *elem_values; + bool *elem_nulls; + + /* + * Compute and deconstruct the array expression. (Notes in + * ExecIndexEvalRuntimeKeys() apply here too.) + */ + arraydatum = ExecEvalExpr(array_expr, + econtext, + &isNull); + if (isNull) + { + result = false; + break; /* no point in evaluating more */ + } + arrayval = DatumGetArrayTypeP(arraydatum); + /* We could cache this data, but not clear it's worth it */ + get_typlenbyvalalign(ARR_ELEMTYPE(arrayval), + &elmlen, &elmbyval, &elmalign); + deconstruct_array(arrayval, + ARR_ELEMTYPE(arrayval), + elmlen, elmbyval, elmalign, + &elem_values, &elem_nulls, &num_elems); + if (num_elems <= 0) + { + result = false; + break; /* no point in evaluating more */ + } + + /* + * Note: we expect the previous array data, if any, to be + * automatically freed by resetting the per-tuple context; hence no + * pfree's here. + */ + arrayKeys[j].elem_values = elem_values; + arrayKeys[j].elem_nulls = elem_nulls; + arrayKeys[j].num_elems = num_elems; + scan_key->sk_argument = elem_values[0]; + if (elem_nulls[0]) + scan_key->sk_flags |= SK_ISNULL; + else + scan_key->sk_flags &= ~SK_ISNULL; + arrayKeys[j].next_elem = 1; + } + + MemoryContextSwitchTo(oldContext); + + return result; +} + +/* + * ExecIndexAdvanceArrayKeys + * Advance to the next set of array key values, if any. + * + * Returns true if there is another set of values to consider, false if not. + * On true result, the scankeys are initialized with the next set of values. + */ +bool +ExecIndexAdvanceArrayKeys(IndexArrayKeyInfo *arrayKeys, int numArrayKeys) +{ + bool found = false; + int j; + + /* + * Note we advance the rightmost array key most quickly, since it will + * correspond to the lowest-order index column among the available + * qualifications. This is hypothesized to result in better locality of + * access in the index. + */ + for (j = numArrayKeys - 1; j >= 0; j--) + { + ScanKey scan_key = arrayKeys[j].scan_key; + int next_elem = arrayKeys[j].next_elem; + int num_elems = arrayKeys[j].num_elems; + Datum *elem_values = arrayKeys[j].elem_values; + bool *elem_nulls = arrayKeys[j].elem_nulls; + + if (next_elem >= num_elems) + { + next_elem = 0; + found = false; /* need to advance next array key */ + } + else + found = true; + scan_key->sk_argument = elem_values[next_elem]; + if (elem_nulls[next_elem]) + scan_key->sk_flags |= SK_ISNULL; + else + scan_key->sk_flags &= ~SK_ISNULL; + arrayKeys[j].next_elem = next_elem + 1; + if (found) + break; + } + + return found; +} + + +/* ---------------------------------------------------------------- + * ExecEndIndexScan + * ---------------------------------------------------------------- + */ +void +ExecEndIndexScan(IndexScanState *node) +{ + Relation indexRelationDesc; + IndexScanDesc indexScanDesc; + + /* + * extract information from the node + */ + indexRelationDesc = node->iss_RelationDesc; + indexScanDesc = node->iss_ScanDesc; + + /* + * Free the exprcontext(s) ... now dead code, see ExecFreeExprContext + */ +#ifdef NOT_USED + ExecFreeExprContext(&node->ss.ps); + if (node->iss_RuntimeContext) + FreeExprContext(node->iss_RuntimeContext, true); +#endif + + /* + * clear out tuple table slots + */ + if (node->ss.ps.ps_ResultTupleSlot) + ExecClearTuple(node->ss.ps.ps_ResultTupleSlot); + ExecClearTuple(node->ss.ss_ScanTupleSlot); + + /* + * close the index relation (no-op if we didn't open it) + */ + if (indexScanDesc) + index_endscan(indexScanDesc); + if (indexRelationDesc) + index_close(indexRelationDesc, NoLock); +} + +/* ---------------------------------------------------------------- + * ExecIndexMarkPos + * + * Note: we assume that no caller attempts to set a mark before having read + * at least one tuple. Otherwise, iss_ScanDesc might still be NULL. + * ---------------------------------------------------------------- + */ +void +ExecIndexMarkPos(IndexScanState *node) +{ + EState *estate = node->ss.ps.state; + EPQState *epqstate = estate->es_epq_active; + + if (epqstate != NULL) + { + /* + * We are inside an EvalPlanQual recheck. If a test tuple exists for + * this relation, then we shouldn't access the index at all. We would + * instead need to save, and later restore, the state of the + * relsubs_done flag, so that re-fetching the test tuple is possible. + * However, given the assumption that no caller sets a mark at the + * start of the scan, we can only get here with relsubs_done[i] + * already set, and so no state need be saved. + */ + Index scanrelid = ((Scan *) node->ss.ps.plan)->scanrelid; + + Assert(scanrelid > 0); + if (epqstate->relsubs_slot[scanrelid - 1] != NULL || + epqstate->relsubs_rowmark[scanrelid - 1] != NULL) + { + /* Verify the claim above */ + if (!epqstate->relsubs_done[scanrelid - 1]) + elog(ERROR, "unexpected ExecIndexMarkPos call in EPQ recheck"); + return; + } + } + + index_markpos(node->iss_ScanDesc); +} + +/* ---------------------------------------------------------------- + * ExecIndexRestrPos + * ---------------------------------------------------------------- + */ +void +ExecIndexRestrPos(IndexScanState *node) +{ + EState *estate = node->ss.ps.state; + EPQState *epqstate = estate->es_epq_active; + + if (estate->es_epq_active != NULL) + { + /* See comments in ExecIndexMarkPos */ + Index scanrelid = ((Scan *) node->ss.ps.plan)->scanrelid; + + Assert(scanrelid > 0); + if (epqstate->relsubs_slot[scanrelid - 1] != NULL || + epqstate->relsubs_rowmark[scanrelid - 1] != NULL) + { + /* Verify the claim above */ + if (!epqstate->relsubs_done[scanrelid - 1]) + elog(ERROR, "unexpected ExecIndexRestrPos call in EPQ recheck"); + return; + } + } + + index_restrpos(node->iss_ScanDesc); +} + +/* ---------------------------------------------------------------- + * ExecInitIndexScan + * + * Initializes the index scan's state information, creates + * scan keys, and opens the base and index relations. + * + * Note: index scans have 2 sets of state information because + * we have to keep track of the base relation and the + * index relation. + * ---------------------------------------------------------------- + */ +IndexScanState * +ExecInitIndexScan(IndexScan *node, EState *estate, int eflags) +{ + IndexScanState *indexstate; + Relation currentRelation; + LOCKMODE lockmode; + + /* + * create state structure + */ + indexstate = makeNode(IndexScanState); + indexstate->ss.ps.plan = (Plan *) node; + indexstate->ss.ps.state = estate; + indexstate->ss.ps.ExecProcNode = ExecIndexScan; + + /* + * Miscellaneous initialization + * + * create expression context for node + */ + ExecAssignExprContext(estate, &indexstate->ss.ps); + + /* + * open the scan relation + */ + currentRelation = ExecOpenScanRelation(estate, node->scan.scanrelid, eflags); + + indexstate->ss.ss_currentRelation = currentRelation; + indexstate->ss.ss_currentScanDesc = NULL; /* no heap scan here */ + + /* + * get the scan type from the relation descriptor. + */ + ExecInitScanTupleSlot(estate, &indexstate->ss, + RelationGetDescr(currentRelation), + table_slot_callbacks(currentRelation)); + + /* + * Initialize result type and projection. + */ + ExecInitResultTypeTL(&indexstate->ss.ps); + ExecAssignScanProjectionInfo(&indexstate->ss); + + /* + * initialize child expressions + * + * Note: we don't initialize all of the indexqual expression, only the + * sub-parts corresponding to runtime keys (see below). Likewise for + * indexorderby, if any. But the indexqualorig expression is always + * initialized even though it will only be used in some uncommon cases --- + * would be nice to improve that. (Problem is that any SubPlans present + * in the expression must be found now...) + */ + indexstate->ss.ps.qual = + ExecInitQual(node->scan.plan.qual, (PlanState *) indexstate); + indexstate->indexqualorig = + ExecInitQual(node->indexqualorig, (PlanState *) indexstate); + indexstate->indexorderbyorig = + ExecInitExprList(node->indexorderbyorig, (PlanState *) indexstate); + + /* + * If we are just doing EXPLAIN (ie, aren't going to run the plan), stop + * here. This allows an index-advisor plugin to EXPLAIN a plan containing + * references to nonexistent indexes. + */ + if (eflags & EXEC_FLAG_EXPLAIN_ONLY) + return indexstate; + + /* Open the index relation. */ + lockmode = exec_rt_fetch(node->scan.scanrelid, estate)->rellockmode; + indexstate->iss_RelationDesc = index_open(node->indexid, lockmode); + + /* + * Initialize index-specific scan state + */ + indexstate->iss_RuntimeKeysReady = false; + indexstate->iss_RuntimeKeys = NULL; + indexstate->iss_NumRuntimeKeys = 0; + + /* + * build the index scan keys from the index qualification + */ + ExecIndexBuildScanKeys((PlanState *) indexstate, + indexstate->iss_RelationDesc, + node->indexqual, + false, + &indexstate->iss_ScanKeys, + &indexstate->iss_NumScanKeys, + &indexstate->iss_RuntimeKeys, + &indexstate->iss_NumRuntimeKeys, + NULL, /* no ArrayKeys */ + NULL); + + /* + * any ORDER BY exprs have to be turned into scankeys in the same way + */ + ExecIndexBuildScanKeys((PlanState *) indexstate, + indexstate->iss_RelationDesc, + node->indexorderby, + true, + &indexstate->iss_OrderByKeys, + &indexstate->iss_NumOrderByKeys, + &indexstate->iss_RuntimeKeys, + &indexstate->iss_NumRuntimeKeys, + NULL, /* no ArrayKeys */ + NULL); + + /* Initialize sort support, if we need to re-check ORDER BY exprs */ + if (indexstate->iss_NumOrderByKeys > 0) + { + int numOrderByKeys = indexstate->iss_NumOrderByKeys; + int i; + ListCell *lco; + ListCell *lcx; + + /* + * Prepare sort support, and look up the data type for each ORDER BY + * expression. + */ + Assert(numOrderByKeys == list_length(node->indexorderbyops)); + Assert(numOrderByKeys == list_length(node->indexorderbyorig)); + indexstate->iss_SortSupport = (SortSupportData *) + palloc0(numOrderByKeys * sizeof(SortSupportData)); + indexstate->iss_OrderByTypByVals = (bool *) + palloc(numOrderByKeys * sizeof(bool)); + indexstate->iss_OrderByTypLens = (int16 *) + palloc(numOrderByKeys * sizeof(int16)); + i = 0; + forboth(lco, node->indexorderbyops, lcx, node->indexorderbyorig) + { + Oid orderbyop = lfirst_oid(lco); + Node *orderbyexpr = (Node *) lfirst(lcx); + Oid orderbyType = exprType(orderbyexpr); + Oid orderbyColl = exprCollation(orderbyexpr); + SortSupport orderbysort = &indexstate->iss_SortSupport[i]; + + /* Initialize sort support */ + orderbysort->ssup_cxt = CurrentMemoryContext; + orderbysort->ssup_collation = orderbyColl; + /* See cmp_orderbyvals() comments on NULLS LAST */ + orderbysort->ssup_nulls_first = false; + /* ssup_attno is unused here and elsewhere */ + orderbysort->ssup_attno = 0; + /* No abbreviation */ + orderbysort->abbreviate = false; + PrepareSortSupportFromOrderingOp(orderbyop, orderbysort); + + get_typlenbyval(orderbyType, + &indexstate->iss_OrderByTypLens[i], + &indexstate->iss_OrderByTypByVals[i]); + i++; + } + + /* allocate arrays to hold the re-calculated distances */ + indexstate->iss_OrderByValues = (Datum *) + palloc(numOrderByKeys * sizeof(Datum)); + indexstate->iss_OrderByNulls = (bool *) + palloc(numOrderByKeys * sizeof(bool)); + + /* and initialize the reorder queue */ + indexstate->iss_ReorderQueue = pairingheap_allocate(reorderqueue_cmp, + indexstate); + } + + /* + * If we have runtime keys, we need an ExprContext to evaluate them. The + * node's standard context won't do because we want to reset that context + * for every tuple. So, build another context just like the other one... + * -tgl 7/11/00 + */ + if (indexstate->iss_NumRuntimeKeys != 0) + { + ExprContext *stdecontext = indexstate->ss.ps.ps_ExprContext; + + ExecAssignExprContext(estate, &indexstate->ss.ps); + indexstate->iss_RuntimeContext = indexstate->ss.ps.ps_ExprContext; + indexstate->ss.ps.ps_ExprContext = stdecontext; + } + else + { + indexstate->iss_RuntimeContext = NULL; + } + + /* + * all done. + */ + return indexstate; +} + + +/* + * ExecIndexBuildScanKeys + * Build the index scan keys from the index qualification expressions + * + * The index quals are passed to the index AM in the form of a ScanKey array. + * This routine sets up the ScanKeys, fills in all constant fields of the + * ScanKeys, and prepares information about the keys that have non-constant + * comparison values. We divide index qual expressions into five types: + * + * 1. Simple operator with constant comparison value ("indexkey op constant"). + * For these, we just fill in a ScanKey containing the constant value. + * + * 2. Simple operator with non-constant value ("indexkey op expression"). + * For these, we create a ScanKey with everything filled in except the + * expression value, and set up an IndexRuntimeKeyInfo struct to drive + * evaluation of the expression at the right times. + * + * 3. RowCompareExpr ("(indexkey, indexkey, ...) op (expr, expr, ...)"). + * For these, we create a header ScanKey plus a subsidiary ScanKey array, + * as specified in access/skey.h. The elements of the row comparison + * can have either constant or non-constant comparison values. + * + * 4. ScalarArrayOpExpr ("indexkey op ANY (array-expression)"). If the index + * supports amsearcharray, we handle these the same as simple operators, + * setting the SK_SEARCHARRAY flag to tell the AM to handle them. Otherwise, + * we create a ScanKey with everything filled in except the comparison value, + * and set up an IndexArrayKeyInfo struct to drive processing of the qual. + * (Note that if we use an IndexArrayKeyInfo struct, the array expression is + * always treated as requiring runtime evaluation, even if it's a constant.) + * + * 5. NullTest ("indexkey IS NULL/IS NOT NULL"). We just fill in the + * ScanKey properly. + * + * This code is also used to prepare ORDER BY expressions for amcanorderbyop + * indexes. The behavior is exactly the same, except that we have to look up + * the operator differently. Note that only cases 1 and 2 are currently + * possible for ORDER BY. + * + * Input params are: + * + * planstate: executor state node we are working for + * index: the index we are building scan keys for + * quals: indexquals (or indexorderbys) expressions + * isorderby: true if processing ORDER BY exprs, false if processing quals + * *runtimeKeys: ptr to pre-existing IndexRuntimeKeyInfos, or NULL if none + * *numRuntimeKeys: number of pre-existing runtime keys + * + * Output params are: + * + * *scanKeys: receives ptr to array of ScanKeys + * *numScanKeys: receives number of scankeys + * *runtimeKeys: receives ptr to array of IndexRuntimeKeyInfos, or NULL if none + * *numRuntimeKeys: receives number of runtime keys + * *arrayKeys: receives ptr to array of IndexArrayKeyInfos, or NULL if none + * *numArrayKeys: receives number of array keys + * + * Caller may pass NULL for arrayKeys and numArrayKeys to indicate that + * IndexArrayKeyInfos are not supported. + */ +void +ExecIndexBuildScanKeys(PlanState *planstate, Relation index, + List *quals, bool isorderby, + ScanKey *scanKeys, int *numScanKeys, + IndexRuntimeKeyInfo **runtimeKeys, int *numRuntimeKeys, + IndexArrayKeyInfo **arrayKeys, int *numArrayKeys) +{ + ListCell *qual_cell; + ScanKey scan_keys; + IndexRuntimeKeyInfo *runtime_keys; + IndexArrayKeyInfo *array_keys; + int n_scan_keys; + int n_runtime_keys; + int max_runtime_keys; + int n_array_keys; + int j; + + /* Allocate array for ScanKey structs: one per qual */ + n_scan_keys = list_length(quals); + scan_keys = (ScanKey) palloc(n_scan_keys * sizeof(ScanKeyData)); + + /* + * runtime_keys array is dynamically resized as needed. We handle it this + * way so that the same runtime keys array can be shared between + * indexquals and indexorderbys, which will be processed in separate calls + * of this function. Caller must be sure to pass in NULL/0 for first + * call. + */ + runtime_keys = *runtimeKeys; + n_runtime_keys = max_runtime_keys = *numRuntimeKeys; + + /* Allocate array_keys as large as it could possibly need to be */ + array_keys = (IndexArrayKeyInfo *) + palloc0(n_scan_keys * sizeof(IndexArrayKeyInfo)); + n_array_keys = 0; + + /* + * for each opclause in the given qual, convert the opclause into a single + * scan key + */ + j = 0; + foreach(qual_cell, quals) + { + Expr *clause = (Expr *) lfirst(qual_cell); + ScanKey this_scan_key = &scan_keys[j++]; + Oid opno; /* operator's OID */ + RegProcedure opfuncid; /* operator proc id used in scan */ + Oid opfamily; /* opfamily of index column */ + int op_strategy; /* operator's strategy number */ + Oid op_lefttype; /* operator's declared input types */ + Oid op_righttype; + Expr *leftop; /* expr on lhs of operator */ + Expr *rightop; /* expr on rhs ... */ + AttrNumber varattno; /* att number used in scan */ + int indnkeyatts; + + indnkeyatts = IndexRelationGetNumberOfKeyAttributes(index); + if (IsA(clause, OpExpr)) + { + /* indexkey op const or indexkey op expression */ + int flags = 0; + Datum scanvalue; + + opno = ((OpExpr *) clause)->opno; + opfuncid = ((OpExpr *) clause)->opfuncid; + + /* + * leftop should be the index key Var, possibly relabeled + */ + leftop = (Expr *) get_leftop(clause); + + if (leftop && IsA(leftop, RelabelType)) + leftop = ((RelabelType *) leftop)->arg; + + Assert(leftop != NULL); + + if (!(IsA(leftop, Var) && + ((Var *) leftop)->varno == INDEX_VAR)) + elog(ERROR, "indexqual doesn't have key on left side"); + + varattno = ((Var *) leftop)->varattno; + if (varattno < 1 || varattno > indnkeyatts) + elog(ERROR, "bogus index qualification"); + + /* + * We have to look up the operator's strategy number. This + * provides a cross-check that the operator does match the index. + */ + opfamily = index->rd_opfamily[varattno - 1]; + + get_op_opfamily_properties(opno, opfamily, isorderby, + &op_strategy, + &op_lefttype, + &op_righttype); + + if (isorderby) + flags |= SK_ORDER_BY; + + /* + * rightop is the constant or variable comparison value + */ + rightop = (Expr *) get_rightop(clause); + + if (rightop && IsA(rightop, RelabelType)) + rightop = ((RelabelType *) rightop)->arg; + + Assert(rightop != NULL); + + if (IsA(rightop, Const)) + { + /* OK, simple constant comparison value */ + scanvalue = ((Const *) rightop)->constvalue; + if (((Const *) rightop)->constisnull) + flags |= SK_ISNULL; + } + else + { + /* Need to treat this one as a runtime key */ + if (n_runtime_keys >= max_runtime_keys) + { + if (max_runtime_keys == 0) + { + max_runtime_keys = 8; + runtime_keys = (IndexRuntimeKeyInfo *) + palloc(max_runtime_keys * sizeof(IndexRuntimeKeyInfo)); + } + else + { + max_runtime_keys *= 2; + runtime_keys = (IndexRuntimeKeyInfo *) + repalloc(runtime_keys, max_runtime_keys * sizeof(IndexRuntimeKeyInfo)); + } + } + runtime_keys[n_runtime_keys].scan_key = this_scan_key; + runtime_keys[n_runtime_keys].key_expr = + ExecInitExpr(rightop, planstate); + runtime_keys[n_runtime_keys].key_toastable = + TypeIsToastable(op_righttype); + n_runtime_keys++; + scanvalue = (Datum) 0; + } + + /* + * initialize the scan key's fields appropriately + */ + ScanKeyEntryInitialize(this_scan_key, + flags, + varattno, /* attribute number to scan */ + op_strategy, /* op's strategy */ + op_righttype, /* strategy subtype */ + ((OpExpr *) clause)->inputcollid, /* collation */ + opfuncid, /* reg proc to use */ + scanvalue); /* constant */ + } + else if (IsA(clause, RowCompareExpr)) + { + /* (indexkey, indexkey, ...) op (expression, expression, ...) */ + RowCompareExpr *rc = (RowCompareExpr *) clause; + ScanKey first_sub_key; + int n_sub_key; + ListCell *largs_cell; + ListCell *rargs_cell; + ListCell *opnos_cell; + ListCell *collids_cell; + + Assert(!isorderby); + + first_sub_key = (ScanKey) + palloc(list_length(rc->opnos) * sizeof(ScanKeyData)); + n_sub_key = 0; + + /* Scan RowCompare columns and generate subsidiary ScanKey items */ + forfour(largs_cell, rc->largs, rargs_cell, rc->rargs, + opnos_cell, rc->opnos, collids_cell, rc->inputcollids) + { + ScanKey this_sub_key = &first_sub_key[n_sub_key]; + int flags = SK_ROW_MEMBER; + Datum scanvalue; + Oid inputcollation; + + leftop = (Expr *) lfirst(largs_cell); + rightop = (Expr *) lfirst(rargs_cell); + opno = lfirst_oid(opnos_cell); + inputcollation = lfirst_oid(collids_cell); + + /* + * leftop should be the index key Var, possibly relabeled + */ + if (leftop && IsA(leftop, RelabelType)) + leftop = ((RelabelType *) leftop)->arg; + + Assert(leftop != NULL); + + if (!(IsA(leftop, Var) && + ((Var *) leftop)->varno == INDEX_VAR)) + elog(ERROR, "indexqual doesn't have key on left side"); + + varattno = ((Var *) leftop)->varattno; + + /* + * We have to look up the operator's associated btree support + * function + */ + if (index->rd_rel->relam != BTREE_AM_OID || + varattno < 1 || varattno > indnkeyatts) + elog(ERROR, "bogus RowCompare index qualification"); + opfamily = index->rd_opfamily[varattno - 1]; + + get_op_opfamily_properties(opno, opfamily, isorderby, + &op_strategy, + &op_lefttype, + &op_righttype); + + if (op_strategy != rc->rctype) + elog(ERROR, "RowCompare index qualification contains wrong operator"); + + opfuncid = get_opfamily_proc(opfamily, + op_lefttype, + op_righttype, + BTORDER_PROC); + if (!RegProcedureIsValid(opfuncid)) + elog(ERROR, "missing support function %d(%u,%u) in opfamily %u", + BTORDER_PROC, op_lefttype, op_righttype, opfamily); + + /* + * rightop is the constant or variable comparison value + */ + if (rightop && IsA(rightop, RelabelType)) + rightop = ((RelabelType *) rightop)->arg; + + Assert(rightop != NULL); + + if (IsA(rightop, Const)) + { + /* OK, simple constant comparison value */ + scanvalue = ((Const *) rightop)->constvalue; + if (((Const *) rightop)->constisnull) + flags |= SK_ISNULL; + } + else + { + /* Need to treat this one as a runtime key */ + if (n_runtime_keys >= max_runtime_keys) + { + if (max_runtime_keys == 0) + { + max_runtime_keys = 8; + runtime_keys = (IndexRuntimeKeyInfo *) + palloc(max_runtime_keys * sizeof(IndexRuntimeKeyInfo)); + } + else + { + max_runtime_keys *= 2; + runtime_keys = (IndexRuntimeKeyInfo *) + repalloc(runtime_keys, max_runtime_keys * sizeof(IndexRuntimeKeyInfo)); + } + } + runtime_keys[n_runtime_keys].scan_key = this_sub_key; + runtime_keys[n_runtime_keys].key_expr = + ExecInitExpr(rightop, planstate); + runtime_keys[n_runtime_keys].key_toastable = + TypeIsToastable(op_righttype); + n_runtime_keys++; + scanvalue = (Datum) 0; + } + + /* + * initialize the subsidiary scan key's fields appropriately + */ + ScanKeyEntryInitialize(this_sub_key, + flags, + varattno, /* attribute number */ + op_strategy, /* op's strategy */ + op_righttype, /* strategy subtype */ + inputcollation, /* collation */ + opfuncid, /* reg proc to use */ + scanvalue); /* constant */ + n_sub_key++; + } + + /* Mark the last subsidiary scankey correctly */ + first_sub_key[n_sub_key - 1].sk_flags |= SK_ROW_END; + + /* + * We don't use ScanKeyEntryInitialize for the header because it + * isn't going to contain a valid sk_func pointer. + */ + MemSet(this_scan_key, 0, sizeof(ScanKeyData)); + this_scan_key->sk_flags = SK_ROW_HEADER; + this_scan_key->sk_attno = first_sub_key->sk_attno; + this_scan_key->sk_strategy = rc->rctype; + /* sk_subtype, sk_collation, sk_func not used in a header */ + this_scan_key->sk_argument = PointerGetDatum(first_sub_key); + } + else if (IsA(clause, ScalarArrayOpExpr)) + { + /* indexkey op ANY (array-expression) */ + ScalarArrayOpExpr *saop = (ScalarArrayOpExpr *) clause; + int flags = 0; + Datum scanvalue; + + Assert(!isorderby); + + Assert(saop->useOr); + opno = saop->opno; + opfuncid = saop->opfuncid; + + /* + * leftop should be the index key Var, possibly relabeled + */ + leftop = (Expr *) linitial(saop->args); + + if (leftop && IsA(leftop, RelabelType)) + leftop = ((RelabelType *) leftop)->arg; + + Assert(leftop != NULL); + + if (!(IsA(leftop, Var) && + ((Var *) leftop)->varno == INDEX_VAR)) + elog(ERROR, "indexqual doesn't have key on left side"); + + varattno = ((Var *) leftop)->varattno; + if (varattno < 1 || varattno > indnkeyatts) + elog(ERROR, "bogus index qualification"); + + /* + * We have to look up the operator's strategy number. This + * provides a cross-check that the operator does match the index. + */ + opfamily = index->rd_opfamily[varattno - 1]; + + get_op_opfamily_properties(opno, opfamily, isorderby, + &op_strategy, + &op_lefttype, + &op_righttype); + + /* + * rightop is the constant or variable array value + */ + rightop = (Expr *) lsecond(saop->args); + + if (rightop && IsA(rightop, RelabelType)) + rightop = ((RelabelType *) rightop)->arg; + + Assert(rightop != NULL); + + if (index->rd_indam->amsearcharray) + { + /* Index AM will handle this like a simple operator */ + flags |= SK_SEARCHARRAY; + if (IsA(rightop, Const)) + { + /* OK, simple constant comparison value */ + scanvalue = ((Const *) rightop)->constvalue; + if (((Const *) rightop)->constisnull) + flags |= SK_ISNULL; + } + else + { + /* Need to treat this one as a runtime key */ + if (n_runtime_keys >= max_runtime_keys) + { + if (max_runtime_keys == 0) + { + max_runtime_keys = 8; + runtime_keys = (IndexRuntimeKeyInfo *) + palloc(max_runtime_keys * sizeof(IndexRuntimeKeyInfo)); + } + else + { + max_runtime_keys *= 2; + runtime_keys = (IndexRuntimeKeyInfo *) + repalloc(runtime_keys, max_runtime_keys * sizeof(IndexRuntimeKeyInfo)); + } + } + runtime_keys[n_runtime_keys].scan_key = this_scan_key; + runtime_keys[n_runtime_keys].key_expr = + ExecInitExpr(rightop, planstate); + + /* + * Careful here: the runtime expression is not of + * op_righttype, but rather is an array of same; so + * TypeIsToastable() isn't helpful. However, we can + * assume that all array types are toastable. + */ + runtime_keys[n_runtime_keys].key_toastable = true; + n_runtime_keys++; + scanvalue = (Datum) 0; + } + } + else + { + /* Executor has to expand the array value */ + array_keys[n_array_keys].scan_key = this_scan_key; + array_keys[n_array_keys].array_expr = + ExecInitExpr(rightop, planstate); + /* the remaining fields were zeroed by palloc0 */ + n_array_keys++; + scanvalue = (Datum) 0; + } + + /* + * initialize the scan key's fields appropriately + */ + ScanKeyEntryInitialize(this_scan_key, + flags, + varattno, /* attribute number to scan */ + op_strategy, /* op's strategy */ + op_righttype, /* strategy subtype */ + saop->inputcollid, /* collation */ + opfuncid, /* reg proc to use */ + scanvalue); /* constant */ + } + else if (IsA(clause, NullTest)) + { + /* indexkey IS NULL or indexkey IS NOT NULL */ + NullTest *ntest = (NullTest *) clause; + int flags; + + Assert(!isorderby); + + /* + * argument should be the index key Var, possibly relabeled + */ + leftop = ntest->arg; + + if (leftop && IsA(leftop, RelabelType)) + leftop = ((RelabelType *) leftop)->arg; + + Assert(leftop != NULL); + + if (!(IsA(leftop, Var) && + ((Var *) leftop)->varno == INDEX_VAR)) + elog(ERROR, "NullTest indexqual has wrong key"); + + varattno = ((Var *) leftop)->varattno; + + /* + * initialize the scan key's fields appropriately + */ + switch (ntest->nulltesttype) + { + case IS_NULL: + flags = SK_ISNULL | SK_SEARCHNULL; + break; + case IS_NOT_NULL: + flags = SK_ISNULL | SK_SEARCHNOTNULL; + break; + default: + elog(ERROR, "unrecognized nulltesttype: %d", + (int) ntest->nulltesttype); + flags = 0; /* keep compiler quiet */ + break; + } + + ScanKeyEntryInitialize(this_scan_key, + flags, + varattno, /* attribute number to scan */ + InvalidStrategy, /* no strategy */ + InvalidOid, /* no strategy subtype */ + InvalidOid, /* no collation */ + InvalidOid, /* no reg proc for this */ + (Datum) 0); /* constant */ + } + else + elog(ERROR, "unsupported indexqual type: %d", + (int) nodeTag(clause)); + } + + Assert(n_runtime_keys <= max_runtime_keys); + + /* Get rid of any unused arrays */ + if (n_array_keys == 0) + { + pfree(array_keys); + array_keys = NULL; + } + + /* + * Return info to our caller. + */ + *scanKeys = scan_keys; + *numScanKeys = n_scan_keys; + *runtimeKeys = runtime_keys; + *numRuntimeKeys = n_runtime_keys; + if (arrayKeys) + { + *arrayKeys = array_keys; + *numArrayKeys = n_array_keys; + } + else if (n_array_keys != 0) + elog(ERROR, "ScalarArrayOpExpr index qual found where not allowed"); +} + +/* ---------------------------------------------------------------- + * Parallel Scan Support + * ---------------------------------------------------------------- + */ + +/* ---------------------------------------------------------------- + * ExecIndexScanEstimate + * + * Compute the amount of space we'll need in the parallel + * query DSM, and inform pcxt->estimator about our needs. + * ---------------------------------------------------------------- + */ +void +ExecIndexScanEstimate(IndexScanState *node, + ParallelContext *pcxt) +{ + EState *estate = node->ss.ps.state; + + node->iss_PscanLen = index_parallelscan_estimate(node->iss_RelationDesc, + estate->es_snapshot); + shm_toc_estimate_chunk(&pcxt->estimator, node->iss_PscanLen); + shm_toc_estimate_keys(&pcxt->estimator, 1); +} + +/* ---------------------------------------------------------------- + * ExecIndexScanInitializeDSM + * + * Set up a parallel index scan descriptor. + * ---------------------------------------------------------------- + */ +void +ExecIndexScanInitializeDSM(IndexScanState *node, + ParallelContext *pcxt) +{ + EState *estate = node->ss.ps.state; + ParallelIndexScanDesc piscan; + + piscan = shm_toc_allocate(pcxt->toc, node->iss_PscanLen); + index_parallelscan_initialize(node->ss.ss_currentRelation, + node->iss_RelationDesc, + estate->es_snapshot, + piscan); + shm_toc_insert(pcxt->toc, node->ss.ps.plan->plan_node_id, piscan); + node->iss_ScanDesc = + index_beginscan_parallel(node->ss.ss_currentRelation, + node->iss_RelationDesc, + node->iss_NumScanKeys, + node->iss_NumOrderByKeys, + piscan); + + /* + * If no run-time keys to calculate or they are ready, go ahead and pass + * the scankeys to the index AM. + */ + if (node->iss_NumRuntimeKeys == 0 || node->iss_RuntimeKeysReady) + index_rescan(node->iss_ScanDesc, + node->iss_ScanKeys, node->iss_NumScanKeys, + node->iss_OrderByKeys, node->iss_NumOrderByKeys); +} + +/* ---------------------------------------------------------------- + * ExecIndexScanReInitializeDSM + * + * Reset shared state before beginning a fresh scan. + * ---------------------------------------------------------------- + */ +void +ExecIndexScanReInitializeDSM(IndexScanState *node, + ParallelContext *pcxt) +{ + index_parallelrescan(node->iss_ScanDesc); +} + +/* ---------------------------------------------------------------- + * ExecIndexScanInitializeWorker + * + * Copy relevant information from TOC into planstate. + * ---------------------------------------------------------------- + */ +void +ExecIndexScanInitializeWorker(IndexScanState *node, + ParallelWorkerContext *pwcxt) +{ + ParallelIndexScanDesc piscan; + + piscan = shm_toc_lookup(pwcxt->toc, node->ss.ps.plan->plan_node_id, false); + node->iss_ScanDesc = + index_beginscan_parallel(node->ss.ss_currentRelation, + node->iss_RelationDesc, + node->iss_NumScanKeys, + node->iss_NumOrderByKeys, + piscan); + + /* + * If no run-time keys to calculate or they are ready, go ahead and pass + * the scankeys to the index AM. + */ + if (node->iss_NumRuntimeKeys == 0 || node->iss_RuntimeKeysReady) + index_rescan(node->iss_ScanDesc, + node->iss_ScanKeys, node->iss_NumScanKeys, + node->iss_OrderByKeys, node->iss_NumOrderByKeys); +} |