PlanState *planstate, ExplainState *es);
static void show_foreignscan_info(ForeignScanState *fsstate, ExplainState *es);
static const char *explain_get_index_name(Oid indexId);
+static void ExplainIndexScanDetails(Oid indexid, ScanDirection indexorderdir,
+ ExplainState *es);
static void ExplainScanTarget(Scan *plan, ExplainState *es);
static void ExplainModifyTarget(ModifyTable *plan, ExplainState *es);
static void ExplainTargetRel(Plan *plan, Index rti, ExplainState *es);
pname = sname = "Seq Scan";
break;
case T_IndexScan:
- if (((IndexScan *) plan)->indexonly)
- pname = sname = "Index Only Scan";
- else
- pname = sname = "Index Scan";
+ pname = sname = "Index Scan";
+ break;
+ case T_IndexOnlyScan:
+ pname = sname = "Index Only Scan";
break;
case T_BitmapIndexScan:
pname = sname = "Bitmap Index Scan";
switch (nodeTag(plan))
{
- case T_IndexScan:
- {
- IndexScan *indexscan = (IndexScan *) plan;
- const char *indexname =
- explain_get_index_name(indexscan->indexid);
-
- if (es->format == EXPLAIN_FORMAT_TEXT)
- {
- if (ScanDirectionIsBackward(indexscan->indexorderdir))
- appendStringInfoString(es->str, " Backward");
- appendStringInfo(es->str, " using %s", indexname);
- }
- else
- {
- const char *scandir;
-
- switch (indexscan->indexorderdir)
- {
- case BackwardScanDirection:
- scandir = "Backward";
- break;
- case NoMovementScanDirection:
- scandir = "NoMovement";
- break;
- case ForwardScanDirection:
- scandir = "Forward";
- break;
- default:
- scandir = "???";
- break;
- }
- ExplainPropertyText("Scan Direction", scandir, es);
- ExplainPropertyText("Index Name", indexname, es);
- }
- }
- /* FALL THRU */
case T_SeqScan:
case T_BitmapHeapScan:
case T_TidScan:
case T_ForeignScan:
ExplainScanTarget((Scan *) plan, es);
break;
+ case T_IndexScan:
+ {
+ IndexScan *indexscan = (IndexScan *) plan;
+
+ ExplainIndexScanDetails(indexscan->indexid,
+ indexscan->indexorderdir,
+ es);
+ ExplainScanTarget((Scan *) indexscan, es);
+ }
+ break;
+ case T_IndexOnlyScan:
+ {
+ IndexOnlyScan *indexonlyscan = (IndexOnlyScan *) plan;
+
+ ExplainIndexScanDetails(indexonlyscan->indexid,
+ indexonlyscan->indexorderdir,
+ es);
+ ExplainScanTarget((Scan *) indexonlyscan, es);
+ }
+ break;
case T_BitmapIndexScan:
{
BitmapIndexScan *bitmapindexscan = (BitmapIndexScan *) plan;
show_instrumentation_count("Rows Removed by Filter", 1,
planstate, es);
break;
+ case T_IndexOnlyScan:
+ show_scan_qual(((IndexOnlyScan *) plan)->indexqual,
+ "Index Cond", planstate, ancestors, es);
+ if (((IndexOnlyScan *) plan)->indexqual)
+ show_instrumentation_count("Rows Removed by Index Recheck", 2,
+ planstate, es);
+ show_scan_qual(((IndexOnlyScan *) plan)->indexorderby,
+ "Order By", planstate, ancestors, es);
+ show_scan_qual(plan->qual, "Filter", planstate, ancestors, es);
+ if (plan->qual)
+ show_instrumentation_count("Rows Removed by Filter", 1,
+ planstate, es);
+ break;
case T_BitmapIndexScan:
show_scan_qual(((BitmapIndexScan *) plan)->indexqualorig,
"Index Cond", planstate, ancestors, es);
return result;
}
+/*
+ * Add some additional details about an IndexScan or IndexOnlyScan
+ */
+static void
+ExplainIndexScanDetails(Oid indexid, ScanDirection indexorderdir,
+ ExplainState *es)
+{
+ const char *indexname = explain_get_index_name(indexid);
+
+ if (es->format == EXPLAIN_FORMAT_TEXT)
+ {
+ if (ScanDirectionIsBackward(indexorderdir))
+ appendStringInfoString(es->str, " Backward");
+ appendStringInfo(es->str, " using %s", indexname);
+ }
+ else
+ {
+ const char *scandir;
+
+ switch (indexorderdir)
+ {
+ case BackwardScanDirection:
+ scandir = "Backward";
+ break;
+ case NoMovementScanDirection:
+ scandir = "NoMovement";
+ break;
+ case ForwardScanDirection:
+ scandir = "Forward";
+ break;
+ default:
+ scandir = "???";
+ break;
+ }
+ ExplainPropertyText("Scan Direction", scandir, es);
+ ExplainPropertyText("Index Name", indexname, es);
+ }
+}
+
/*
* Show the target of a Scan node
*/
{
case T_SeqScan:
case T_IndexScan:
+ case T_IndexOnlyScan:
case T_BitmapHeapScan:
case T_TidScan:
case T_ForeignScan:
oldContext = MemoryContextSwitchTo(estate->es_query_cxt);
tgqual = stringToNode(trigger->tgqual);
- /* Change references to OLD and NEW to INNER and OUTER */
- ChangeVarNodes(tgqual, PRS2_OLD_VARNO, INNER, 0);
- ChangeVarNodes(tgqual, PRS2_NEW_VARNO, OUTER, 0);
+ /* Change references to OLD and NEW to INNER_VAR and OUTER_VAR */
+ ChangeVarNodes(tgqual, PRS2_OLD_VARNO, INNER_VAR, 0);
+ ChangeVarNodes(tgqual, PRS2_NEW_VARNO, OUTER_VAR, 0);
/* ExecQual wants implicit-AND form */
tgqual = (Node *) make_ands_implicit((Expr *) tgqual);
*predicate = (List *) ExecPrepareExpr((Expr *) tgqual, estate);
/*
* Finally evaluate the expression, making the old and/or new tuples
- * available as INNER/OUTER respectively.
+ * available as INNER_VAR/OUTER_VAR respectively.
*/
econtext->ecxt_innertuple = oldslot;
econtext->ecxt_outertuple = newslot;
execUtils.o functions.o instrument.o nodeAppend.o nodeAgg.o \
nodeBitmapAnd.o nodeBitmapOr.o \
nodeBitmapHeapscan.o nodeBitmapIndexscan.o nodeHash.o \
- nodeHashjoin.o nodeIndexscan.o nodeLimit.o nodeLockRows.o \
+ nodeHashjoin.o nodeIndexscan.o nodeIndexonlyscan.o \
+ nodeLimit.o nodeLockRows.o \
nodeMaterial.o nodeMergeAppend.o nodeMergejoin.o nodeModifyTable.o \
nodeNestloop.o nodeFunctionscan.o nodeRecursiveunion.o nodeResult.o \
nodeSeqscan.o nodeSetOp.o nodeSort.o nodeUnique.o \
#include "executor/nodeGroup.h"
#include "executor/nodeHash.h"
#include "executor/nodeHashjoin.h"
+#include "executor/nodeIndexonlyscan.h"
#include "executor/nodeIndexscan.h"
#include "executor/nodeLimit.h"
#include "executor/nodeLockRows.h"
ExecReScanIndexScan((IndexScanState *) node);
break;
+ case T_IndexOnlyScanState:
+ ExecReScanIndexOnlyScan((IndexOnlyScanState *) node);
+ break;
+
case T_BitmapIndexScanState:
ExecReScanBitmapIndexScan((BitmapIndexScanState *) node);
break;
ExecIndexMarkPos((IndexScanState *) node);
break;
+ case T_IndexOnlyScanState:
+ ExecIndexOnlyMarkPos((IndexOnlyScanState *) node);
+ break;
+
case T_TidScanState:
ExecTidMarkPos((TidScanState *) node);
break;
ExecIndexRestrPos((IndexScanState *) node);
break;
+ case T_IndexOnlyScanState:
+ ExecIndexOnlyRestrPos((IndexOnlyScanState *) node);
+ break;
+
case T_TidScanState:
ExecTidRestrPos((TidScanState *) node);
break;
{
case T_SeqScan:
case T_IndexScan:
+ case T_IndexOnlyScan:
case T_TidScan:
case T_ValuesScan:
case T_Material:
return IndexSupportsBackwardScan(((IndexScan *) node)->indexid) &&
TargetListSupportsBackwardScan(node->targetlist);
+ case T_IndexOnlyScan:
+ return IndexSupportsBackwardScan(((IndexOnlyScan *) node)->indexid) &&
+ TargetListSupportsBackwardScan(node->targetlist);
+
case T_SubqueryScan:
return ExecSupportsBackwardScan(((SubqueryScan *) node)->subplan) &&
TargetListSupportsBackwardScan(node->targetlist);
}
/*
- * An IndexScan node supports backward scan only if the index's AM does.
+ * An IndexScan or IndexOnlyScan node supports backward scan only if the
+ * index's AM does.
*/
static bool
IndexSupportsBackwardScan(Oid indexid)
*/
case T_SeqScanState:
case T_IndexScanState:
+ case T_IndexOnlyScanState:
case T_BitmapHeapScanState:
case T_TidScanState:
{
#include "executor/nodeGroup.h"
#include "executor/nodeHash.h"
#include "executor/nodeHashjoin.h"
+#include "executor/nodeIndexonlyscan.h"
#include "executor/nodeIndexscan.h"
#include "executor/nodeLimit.h"
#include "executor/nodeLockRows.h"
estate, eflags);
break;
+ case T_IndexOnlyScan:
+ result = (PlanState *) ExecInitIndexOnlyScan((IndexOnlyScan *) node,
+ estate, eflags);
+ break;
+
case T_BitmapIndexScan:
result = (PlanState *) ExecInitBitmapIndexScan((BitmapIndexScan *) node,
estate, eflags);
result = ExecIndexScan((IndexScanState *) node);
break;
+ case T_IndexOnlyScanState:
+ result = ExecIndexOnlyScan((IndexOnlyScanState *) node);
+ break;
+
/* BitmapIndexScanState does not yield tuples */
case T_BitmapHeapScanState:
ExecEndIndexScan((IndexScanState *) node);
break;
+ case T_IndexOnlyScanState:
+ ExecEndIndexOnlyScan((IndexOnlyScanState *) node);
+ break;
+
case T_BitmapIndexScanState:
ExecEndBitmapIndexScan((BitmapIndexScanState *) node);
break;
/* Get the input slot and attribute number we want */
switch (variable->varno)
{
- case INNER: /* get the tuple from the inner node */
+ case INNER_VAR: /* get the tuple from the inner node */
slot = econtext->ecxt_innertuple;
break;
- case OUTER: /* get the tuple from the outer node */
+ case OUTER_VAR: /* get the tuple from the outer node */
slot = econtext->ecxt_outertuple;
break;
+ /* INDEX_VAR is handled by default case */
+
default: /* get the tuple from the relation being
* scanned */
slot = econtext->ecxt_scantuple;
/* Get the input slot and attribute number we want */
switch (variable->varno)
{
- case INNER: /* get the tuple from the inner node */
+ case INNER_VAR: /* get the tuple from the inner node */
slot = econtext->ecxt_innertuple;
break;
- case OUTER: /* get the tuple from the outer node */
+ case OUTER_VAR: /* get the tuple from the outer node */
slot = econtext->ecxt_outertuple;
break;
+ /* INDEX_VAR is handled by default case */
+
default: /* get the tuple from the relation being
* scanned */
slot = econtext->ecxt_scantuple;
/* Get the input slot we want */
switch (variable->varno)
{
- case INNER: /* get the tuple from the inner node */
+ case INNER_VAR: /* get the tuple from the inner node */
slot = econtext->ecxt_innertuple;
break;
- case OUTER: /* get the tuple from the outer node */
+ case OUTER_VAR: /* get the tuple from the outer node */
slot = econtext->ecxt_outertuple;
break;
+ /* INDEX_VAR is handled by default case */
+
default: /* get the tuple from the relation being
* scanned */
slot = econtext->ecxt_scantuple;
/* Get the input slot we want */
switch (variable->varno)
{
- case INNER: /* get the tuple from the inner node */
+ case INNER_VAR: /* get the tuple from the inner node */
slot = econtext->ecxt_innertuple;
break;
- case OUTER: /* get the tuple from the outer node */
+ case OUTER_VAR: /* get the tuple from the outer node */
slot = econtext->ecxt_outertuple;
break;
+ /* INDEX_VAR is handled by default case */
+
default: /* get the tuple from the relation being
* scanned */
slot = econtext->ecxt_scantuple;
ExecAssignScanProjectionInfo(ScanState *node)
{
Scan *scan = (Scan *) node->ps.plan;
+ Index varno;
+
+ /* Vars in an index-only scan's tlist should be INDEX_VAR */
+ if (IsA(scan, IndexOnlyScan))
+ varno = INDEX_VAR;
+ else
+ varno = scan->scanrelid;
if (tlist_matches_tupdesc(&node->ps,
scan->plan.targetlist,
- scan->scanrelid,
+ varno,
node->ss_ScanTupleSlot->tts_tupleDescriptor))
node->ps.ps_ProjInfo = NULL;
else
switch (variable->varno)
{
- case INNER:
+ case INNER_VAR:
varSlotOffsets[numSimpleVars] = offsetof(ExprContext,
ecxt_innertuple);
if (projInfo->pi_lastInnerVar < attnum)
projInfo->pi_lastInnerVar = attnum;
break;
- case OUTER:
+ case OUTER_VAR:
varSlotOffsets[numSimpleVars] = offsetof(ExprContext,
ecxt_outertuple);
if (projInfo->pi_lastOuterVar < attnum)
projInfo->pi_lastOuterVar = attnum;
break;
+ /* INDEX_VAR is handled by default case */
+
default:
varSlotOffsets[numSimpleVars] = offsetof(ExprContext,
ecxt_scantuple);
switch (variable->varno)
{
- case INNER:
+ case INNER_VAR:
if (projInfo->pi_lastInnerVar < attnum)
projInfo->pi_lastInnerVar = attnum;
break;
- case OUTER:
+ case OUTER_VAR:
if (projInfo->pi_lastOuterVar < attnum)
projInfo->pi_lastOuterVar = attnum;
break;
+ /* INDEX_VAR is handled by default case */
+
default:
if (projInfo->pi_lastScanVar < attnum)
projInfo->pi_lastScanVar = attnum;
{
Var *var = (Var *) node;
- /* setrefs.c should have set the varno to OUTER */
- Assert(var->varno == OUTER);
+ /* setrefs.c should have set the varno to OUTER_VAR */
+ Assert(var->varno == OUTER_VAR);
Assert(var->varlevelsup == 0);
*colnos = bms_add_member(*colnos, var->varattno);
return false;
*/
ExecIndexBuildScanKeys((PlanState *) indexstate,
indexstate->biss_RelationDesc,
- node->scan.scanrelid,
node->indexqual,
false,
&indexstate->biss_ScanKeys,
* Compute the hash value for a tuple
*
* The tuple to be tested must be in either econtext->ecxt_outertuple or
- * econtext->ecxt_innertuple. Vars in the hashkeys expressions reference
- * either OUTER or INNER.
+ * econtext->ecxt_innertuple. Vars in the hashkeys expressions should have
+ * varno either OUTER_VAR or INNER_VAR.
*
* A TRUE result means the tuple's hash value has been successfully computed
* and stored at *hashvalue. A FALSE result means the tuple cannot match
--- /dev/null
+/*-------------------------------------------------------------------------
+ *
+ * nodeIndexonlyscan.c
+ * Routines to support index-only scans
+ *
+ * Portions Copyright (c) 1996-2011, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ * src/backend/executor/nodeIndexonlyscan.c
+ *
+ *-------------------------------------------------------------------------
+ */
+/*
+ * INTERFACE ROUTINES
+ * ExecIndexOnlyScan scans an index
+ * IndexOnlyNext retrieve next tuple
+ * ExecInitIndexOnlyScan creates and initializes state info.
+ * ExecReScanIndexOnlyScan rescans the indexed relation.
+ * ExecEndIndexOnlyScan releases all storage.
+ * ExecIndexOnlyMarkPos marks scan position.
+ * ExecIndexOnlyRestrPos restores scan position.
+ */
+#include "postgres.h"
+
+#include "access/relscan.h"
+#include "access/visibilitymap.h"
+#include "catalog/pg_opfamily.h"
+#include "catalog/pg_type.h"
+#include "executor/execdebug.h"
+#include "executor/nodeIndexonlyscan.h"
+#include "executor/nodeIndexscan.h"
+#include "storage/bufmgr.h"
+#include "utils/memutils.h"
+#include "utils/rel.h"
+
+
+static TupleTableSlot *IndexOnlyNext(IndexOnlyScanState *node);
+static void StoreIndexTuple(TupleTableSlot *slot, IndexTuple itup,
+ Relation indexRel);
+
+
+/* ----------------------------------------------------------------
+ * IndexOnlyNext
+ *
+ * Retrieve a tuple from the IndexOnlyScan node's index.
+ * ----------------------------------------------------------------
+ */
+static TupleTableSlot *
+IndexOnlyNext(IndexOnlyScanState *node)
+{
+ EState *estate;
+ ExprContext *econtext;
+ ScanDirection direction;
+ IndexScanDesc scandesc;
+ HeapTuple tuple;
+ TupleTableSlot *slot;
+ ItemPointer tid;
+
+ /*
+ * 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(((IndexOnlyScan *) node->ss.ps.plan)->indexorderdir))
+ {
+ if (ScanDirectionIsForward(direction))
+ direction = BackwardScanDirection;
+ else if (ScanDirectionIsBackward(direction))
+ direction = ForwardScanDirection;
+ }
+ scandesc = node->ioss_ScanDesc;
+ econtext = node->ss.ps.ps_ExprContext;
+ slot = node->ss.ss_ScanTupleSlot;
+
+ /*
+ * OK, now that we have what we need, fetch the next tuple.
+ */
+ while ((tid = index_getnext_tid(scandesc, direction)) != NULL)
+ {
+ /*
+ * We can skip the heap fetch if the TID references a heap page on
+ * which all tuples are known visible to everybody. In any case,
+ * we'll use the index tuple not the heap tuple as the data source.
+ */
+ if (!visibilitymap_test(scandesc->heapRelation,
+ ItemPointerGetBlockNumber(tid),
+ &node->ioss_VMBuffer))
+ {
+ /*
+ * Rats, we have to visit the heap to check visibility.
+ */
+ tuple = index_fetch_heap(scandesc);
+ if (tuple == NULL)
+ continue; /* no visible tuple, try next index entry */
+
+ /*
+ * Only MVCC snapshots are supported here, so there should be no
+ * need to keep following the HOT chain once a visible entry has
+ * been found. If we did want to allow that, we'd need to keep
+ * more state to remember not to call index_getnext_tid next time.
+ */
+ if (scandesc->xs_continue_hot)
+ elog(ERROR, "non-MVCC snapshots are not supported in index-only scans");
+
+ /*
+ * Note: at this point we are holding a pin on the heap page, as
+ * recorded in scandesc->xs_cbuf. We could release that pin now,
+ * but it's not clear whether it's a win to do so. The next index
+ * entry might require a visit to the same heap page.
+ */
+ }
+
+ /*
+ * Fill the scan tuple slot with data from the index.
+ */
+ StoreIndexTuple(slot, scandesc->xs_itup, scandesc->indexRelation);
+
+ /*
+ * If the index was lossy, we have to recheck the index quals.
+ * (Currently, this can never happen, but we should support the case
+ * for possible future use, eg with GiST indexes.)
+ */
+ if (scandesc->xs_recheck)
+ {
+ econtext->ecxt_scantuple = slot;
+ ResetExprContext(econtext);
+ if (!ExecQual(node->indexqual, econtext, false))
+ {
+ /* 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..
+ */
+ return ExecClearTuple(slot);
+}
+
+/*
+ * StoreIndexTuple
+ * Fill the slot with data from the index tuple.
+ *
+ * At some point this might be generally-useful functionality, but
+ * right now we don't need it elsewhere.
+ */
+static void
+StoreIndexTuple(TupleTableSlot *slot, IndexTuple itup, Relation indexRel)
+{
+ TupleDesc indexDesc = RelationGetDescr(indexRel);
+ int nindexatts = indexDesc->natts;
+ Datum *values = slot->tts_values;
+ bool *isnull = slot->tts_isnull;
+ int i;
+
+ /*
+ * Note: we must use the index relation's tupdesc in index_getattr,
+ * not the slot's tupdesc, because of index_descriptor_hack().
+ */
+ Assert(slot->tts_tupleDescriptor->natts == nindexatts);
+
+ ExecClearTuple(slot);
+ for (i = 0; i < nindexatts; i++)
+ values[i] = index_getattr(itup, i + 1, indexDesc, &isnull[i]);
+ ExecStoreVirtualTuple(slot);
+}
+
+/*
+ * index_descriptor_hack -- ugly kluge to make index's tupdesc OK for slot
+ *
+ * This is necessary because, alone among btree opclasses, name_ops uses
+ * a storage type (cstring) different from its input type. The index
+ * tuple descriptor will show "cstring", which is correct, but we have to
+ * expose "name" as the slot datatype or ExecEvalVar will whine. If we
+ * ever want to have any other cases with a different storage type, we ought
+ * to think of a cleaner solution than this.
+ */
+static TupleDesc
+index_descriptor_hack(Relation indexRel)
+{
+ TupleDesc tupdesc = RelationGetDescr(indexRel);
+ int i;
+
+ /* copy so we can scribble on it safely */
+ tupdesc = CreateTupleDescCopy(tupdesc);
+
+ for (i = 0; i < tupdesc->natts; i++)
+ {
+ if (indexRel->rd_opfamily[i] == NAME_BTREE_FAM_OID &&
+ tupdesc->attrs[i]->atttypid == CSTRINGOID)
+ {
+ tupdesc->attrs[i]->atttypid = NAMEOID;
+
+ /*
+ * We set attlen to match the type OID just in case anything looks
+ * at it. Note that this is safe only because StoreIndexTuple
+ * will insert the data as a virtual tuple, and we don't expect
+ * anything will try to materialize the scan tuple slot.
+ */
+ tupdesc->attrs[i]->attlen = NAMEDATALEN;
+ }
+ }
+
+ return tupdesc;
+}
+
+/*
+ * IndexOnlyRecheck -- access method routine to recheck a tuple in EvalPlanQual
+ *
+ * This can't really happen, since an index can't supply CTID which would
+ * be necessary data for any potential EvalPlanQual target relation. If it
+ * did happen, the EPQ code would pass us the wrong data, namely a heap
+ * tuple not an index tuple. So throw an error.
+ */
+static bool
+IndexOnlyRecheck(IndexOnlyScanState *node, TupleTableSlot *slot)
+{
+ elog(ERROR, "EvalPlanQual recheck is not supported in index-only scans");
+ return false; /* keep compiler quiet */
+}
+
+/* ----------------------------------------------------------------
+ * ExecIndexOnlyScan(node)
+ * ----------------------------------------------------------------
+ */
+TupleTableSlot *
+ExecIndexOnlyScan(IndexOnlyScanState *node)
+{
+ /*
+ * If we have runtime keys and they've not already been set up, do it now.
+ */
+ if (node->ioss_NumRuntimeKeys != 0 && !node->ioss_RuntimeKeysReady)
+ ExecReScan((PlanState *) node);
+
+ return ExecScan(&node->ss,
+ (ExecScanAccessMtd) IndexOnlyNext,
+ (ExecScanRecheckMtd) IndexOnlyRecheck);
+}
+
+/* ----------------------------------------------------------------
+ * ExecReScanIndexOnlyScan(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
+ExecReScanIndexOnlyScan(IndexOnlyScanState *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->ioss_NumRuntimeKeys != 0)
+ {
+ ExprContext *econtext = node->ioss_RuntimeContext;
+
+ ResetExprContext(econtext);
+ ExecIndexEvalRuntimeKeys(econtext,
+ node->ioss_RuntimeKeys,
+ node->ioss_NumRuntimeKeys);
+ }
+ node->ioss_RuntimeKeysReady = true;
+
+ /* reset index scan */
+ index_rescan(node->ioss_ScanDesc,
+ node->ioss_ScanKeys, node->ioss_NumScanKeys,
+ node->ioss_OrderByKeys, node->ioss_NumOrderByKeys);
+
+ ExecScanReScan(&node->ss);
+}
+
+
+/* ----------------------------------------------------------------
+ * ExecEndIndexOnlyScan
+ * ----------------------------------------------------------------
+ */
+void
+ExecEndIndexOnlyScan(IndexOnlyScanState *node)
+{
+ Relation indexRelationDesc;
+ IndexScanDesc indexScanDesc;
+ Relation relation;
+
+ /*
+ * extract information from the node
+ */
+ indexRelationDesc = node->ioss_RelationDesc;
+ indexScanDesc = node->ioss_ScanDesc;
+ relation = node->ss.ss_currentRelation;
+
+ /* Release VM buffer pin, if any. */
+ if (node->ioss_VMBuffer != InvalidBuffer)
+ {
+ ReleaseBuffer(node->ioss_VMBuffer);
+ node->ioss_VMBuffer = InvalidBuffer;
+ }
+
+ /*
+ * Free the exprcontext(s) ... now dead code, see ExecFreeExprContext
+ */
+#ifdef NOT_USED
+ ExecFreeExprContext(&node->ss.ps);
+ if (node->ioss_RuntimeContext)
+ FreeExprContext(node->ioss_RuntimeContext, true);
+#endif
+
+ /*
+ * clear out tuple table slots
+ */
+ 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);
+
+ /*
+ * close the heap relation.
+ */
+ ExecCloseScanRelation(relation);
+}
+
+/* ----------------------------------------------------------------
+ * ExecIndexOnlyMarkPos
+ * ----------------------------------------------------------------
+ */
+void
+ExecIndexOnlyMarkPos(IndexOnlyScanState *node)
+{
+ index_markpos(node->ioss_ScanDesc);
+}
+
+/* ----------------------------------------------------------------
+ * ExecIndexOnlyRestrPos
+ * ----------------------------------------------------------------
+ */
+void
+ExecIndexOnlyRestrPos(IndexOnlyScanState *node)
+{
+ index_restrpos(node->ioss_ScanDesc);
+}
+
+/* ----------------------------------------------------------------
+ * ExecInitIndexOnlyScan
+ *
+ * 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.
+ * ----------------------------------------------------------------
+ */
+IndexOnlyScanState *
+ExecInitIndexOnlyScan(IndexOnlyScan *node, EState *estate, int eflags)
+{
+ IndexOnlyScanState *indexstate;
+ Relation currentRelation;
+ bool relistarget;
+ TupleDesc tupDesc;
+
+ /*
+ * create state structure
+ */
+ indexstate = makeNode(IndexOnlyScanState);
+ indexstate->ss.ps.plan = (Plan *) node;
+ indexstate->ss.ps.state = estate;
+
+ /*
+ * Miscellaneous initialization
+ *
+ * create expression context for node
+ */
+ ExecAssignExprContext(estate, &indexstate->ss.ps);
+
+ indexstate->ss.ps.ps_TupFromTlist = false;
+
+ /*
+ * initialize child expressions
+ *
+ * Note: we don't initialize all of the indexorderby expression, only the
+ * sub-parts corresponding to runtime keys (see below).
+ */
+ indexstate->ss.ps.targetlist = (List *)
+ ExecInitExpr((Expr *) node->scan.plan.targetlist,
+ (PlanState *) indexstate);
+ indexstate->ss.ps.qual = (List *)
+ ExecInitExpr((Expr *) node->scan.plan.qual,
+ (PlanState *) indexstate);
+ indexstate->indexqual = (List *)
+ ExecInitExpr((Expr *) node->indexqual,
+ (PlanState *) indexstate);
+
+ /*
+ * tuple table initialization
+ */
+ ExecInitResultTupleSlot(estate, &indexstate->ss.ps);
+ ExecInitScanTupleSlot(estate, &indexstate->ss);
+
+ /*
+ * open the base relation and acquire appropriate lock on it.
+ */
+ currentRelation = ExecOpenScanRelation(estate, node->scan.scanrelid);
+
+ indexstate->ss.ss_currentRelation = currentRelation;
+ indexstate->ss.ss_currentScanDesc = NULL; /* no heap scan here */
+
+ /*
+ * Initialize result tuple type.
+ */
+ ExecAssignResultTypeFromTL(&indexstate->ss.ps);
+
+ /*
+ * 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.
+ *
+ * If the parent table is one of the target relations of the query, then
+ * InitPlan already opened and write-locked the index, so we can avoid
+ * taking another lock here. Otherwise we need a normal reader's lock.
+ */
+ relistarget = ExecRelationIsTargetRelation(estate, node->scan.scanrelid);
+ indexstate->ioss_RelationDesc = index_open(node->indexid,
+ relistarget ? NoLock : AccessShareLock);
+
+ /*
+ * Now we can get the scan tuple's type (which is the index's rowtype,
+ * not the heap's) and initialize result projection info.
+ */
+ tupDesc = index_descriptor_hack(indexstate->ioss_RelationDesc);
+ ExecAssignScanType(&indexstate->ss, tupDesc);
+ ExecAssignScanProjectionInfo(&indexstate->ss);
+
+ /*
+ * Initialize index-specific scan state
+ */
+ indexstate->ioss_RuntimeKeysReady = false;
+ indexstate->ioss_RuntimeKeys = NULL;
+ indexstate->ioss_NumRuntimeKeys = 0;
+
+ /*
+ * build the index scan keys from the index qualification
+ */
+ ExecIndexBuildScanKeys((PlanState *) indexstate,
+ indexstate->ioss_RelationDesc,
+ node->indexqual,
+ false,
+ &indexstate->ioss_ScanKeys,
+ &indexstate->ioss_NumScanKeys,
+ &indexstate->ioss_RuntimeKeys,
+ &indexstate->ioss_NumRuntimeKeys,
+ NULL, /* no ArrayKeys */
+ NULL);
+
+ /*
+ * any ORDER BY exprs have to be turned into scankeys in the same way
+ */
+ ExecIndexBuildScanKeys((PlanState *) indexstate,
+ indexstate->ioss_RelationDesc,
+ node->indexorderby,
+ true,
+ &indexstate->ioss_OrderByKeys,
+ &indexstate->ioss_NumOrderByKeys,
+ &indexstate->ioss_RuntimeKeys,
+ &indexstate->ioss_NumRuntimeKeys,
+ NULL, /* no ArrayKeys */
+ NULL);
+
+ /*
+ * 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->ioss_NumRuntimeKeys != 0)
+ {
+ ExprContext *stdecontext = indexstate->ss.ps.ps_ExprContext;
+
+ ExecAssignExprContext(estate, &indexstate->ss.ps);
+ indexstate->ioss_RuntimeContext = indexstate->ss.ps.ps_ExprContext;
+ indexstate->ss.ps.ps_ExprContext = stdecontext;
+ }
+ else
+ {
+ indexstate->ioss_RuntimeContext = NULL;
+ }
+
+ /*
+ * Initialize scan descriptor.
+ */
+ indexstate->ioss_ScanDesc = index_beginscan(currentRelation,
+ indexstate->ioss_RelationDesc,
+ estate->es_snapshot,
+ indexstate->ioss_NumScanKeys,
+ indexstate->ioss_NumOrderByKeys);
+
+ /* Set it up for index-only scan */
+ indexstate->ioss_ScanDesc->xs_want_itup = true;
+ indexstate->ioss_VMBuffer = InvalidBuffer;
+
+ /*
+ * If no run-time keys to calculate, go ahead and pass the scankeys to the
+ * index AM.
+ */
+ if (indexstate->ioss_NumRuntimeKeys == 0)
+ index_rescan(indexstate->ioss_ScanDesc,
+ indexstate->ioss_ScanKeys,
+ indexstate->ioss_NumScanKeys,
+ indexstate->ioss_OrderByKeys,
+ indexstate->ioss_NumOrderByKeys);
+
+ /*
+ * all done.
+ */
+ return indexstate;
+}
*/
/*
* INTERFACE ROUTINES
- * ExecIndexScan scans a relation using indices
- * ExecIndexNext using index to retrieve next tuple
+ * ExecIndexScan scans a relation using an index
+ * IndexNext retrieve next tuple using index
* ExecInitIndexScan creates and initializes state info.
* ExecReScanIndexScan rescans the indexed relation.
* ExecEndIndexScan releases all storage.
#include "access/nbtree.h"
#include "access/relscan.h"
-#include "access/visibilitymap.h"
#include "executor/execdebug.h"
#include "executor/nodeIndexscan.h"
#include "optimizer/clauses.h"
static TupleTableSlot *IndexNext(IndexScanState *node);
-static void IndexStoreHeapTuple(TupleTableSlot *slot, IndexScanDesc scandesc);
/* ----------------------------------------------------------------
IndexScanDesc scandesc;
HeapTuple tuple;
TupleTableSlot *slot;
- ItemPointer tid;
/*
* extract necessary information from index scan node
slot = node->ss.ss_ScanTupleSlot;
/*
- * OK, now that we have what we need, fetch the next TID.
+ * ok, now that we have what we need, fetch the next tuple.
*/
- while ((tid = index_getnext_tid(scandesc, direction)) != NULL)
+ while ((tuple = index_getnext(scandesc, direction)) != NULL)
{
/*
- * Attempt index-only scan, if possible. For this, we need to have
- * gotten an index tuple from the AM, and we need the TID to reference
- * a heap page on which all tuples are known visible to everybody.
- * If that's the case, we don't need to visit the heap page for tuple
- * visibility testing, and we don't need any column values that are
- * not available from the index.
- *
- * Note: in the index-only path, we are still holding pin on the
- * scan's xs_cbuf, ie, the previously visited heap page. It's not
- * clear whether it'd be better to release that pin.
+ * Store the scanned tuple in the scan tuple slot of the scan state.
+ * Note: we pass 'false' because tuples returned by amgetnext are
+ * pointers onto disk pages and must not be pfree()'d.
*/
- if (scandesc->xs_want_itup &&
- visibilitymap_test(scandesc->heapRelation,
- ItemPointerGetBlockNumber(tid),
- &node->iss_VMBuffer))
- {
- /*
- * Convert index tuple to look like a heap tuple, and store the
- * results in the scan tuple slot.
- */
- IndexStoreHeapTuple(slot, scandesc);
- }
- else
- {
- /* Index-only approach not possible, so fetch heap tuple. */
- tuple = index_fetch_heap(scandesc);
-
- /* Tuple might not be visible. */
- if (tuple == NULL)
- continue;
-
- /*
- * Only MVCC snapshots are supported here, so there should be no
- * need to keep following the HOT chain once a visible entry has
- * been found. If we did want to allow that, we'd need to keep
- * more state to remember not to call index_getnext_tid next time.
- */
- if (scandesc->xs_continue_hot)
- elog(ERROR, "unsupported use of non-MVCC snapshot in executor");
-
- /*
- * Store the scanned tuple in the scan tuple slot of the scan
- * state.
- *
- * Note: we pass 'false' because tuples returned by amgetnext are
- * pointers onto disk pages and must not be pfree()'d.
- */
- ExecStoreTuple(tuple, /* tuple to store */
- slot, /* slot to store in */
- scandesc->xs_cbuf, /* buffer containing tuple */
- false); /* don't pfree */
- }
+ ExecStoreTuple(tuple, /* tuple to store */
+ slot, /* slot to store in */
+ scandesc->xs_cbuf, /* buffer containing tuple */
+ false); /* don't pfree */
/*
* If the index was lossy, we have to recheck the index quals using
- * the real tuple.
+ * the fetched tuple.
*/
if (scandesc->xs_recheck)
{
return ExecClearTuple(slot);
}
-/*
- * IndexStoreHeapTuple
- *
- * When performing an index-only scan, we build a faux heap tuple
- * from the index tuple. Columns not present in the index are set to
- * NULL, which is OK because we know they won't be referenced.
- *
- * The faux tuple is built as a virtual tuple that depends on the
- * scandesc's xs_itup, so that must remain valid for as long as we
- * need the slot contents.
- */
-static void
-IndexStoreHeapTuple(TupleTableSlot *slot, IndexScanDesc scandesc)
-{
- Form_pg_index indexForm = scandesc->indexRelation->rd_index;
- TupleDesc indexDesc = RelationGetDescr(scandesc->indexRelation);
- int nindexatts = indexDesc->natts;
- int nheapatts = slot->tts_tupleDescriptor->natts;
- Datum *values = slot->tts_values;
- bool *isnull = slot->tts_isnull;
- int i;
-
- /* We must first set the slot to empty, and mark all columns as null */
- ExecClearTuple(slot);
-
- memset(isnull, true, nheapatts * sizeof(bool));
-
- /* Transpose index tuple into heap tuple. */
- for (i = 0; i < nindexatts; i++)
- {
- int indexatt = indexForm->indkey.values[i];
-
- /* Ignore expression columns, as well as system attributes */
- if (indexatt <= 0)
- continue;
-
- Assert(indexatt <= nheapatts);
-
- values[indexatt - 1] = index_getattr(scandesc->xs_itup, i + 1,
- indexDesc,
- &isnull[indexatt - 1]);
- }
-
- /* And now we can mark the slot as holding a virtual tuple. */
- ExecStoreVirtualTuple(slot);
-}
-
/*
* IndexRecheck -- access method routine to recheck a tuple in EvalPlanQual
*/
indexScanDesc = node->iss_ScanDesc;
relation = node->ss.ss_currentRelation;
- /* Release VM buffer pin, if any. */
- if (node->iss_VMBuffer != InvalidBuffer)
- {
- ReleaseBuffer(node->iss_VMBuffer);
- node->iss_VMBuffer = InvalidBuffer;
- }
-
/*
* Free the exprcontext(s) ... now dead code, see ExecFreeExprContext
*/
*/
ExecIndexBuildScanKeys((PlanState *) indexstate,
indexstate->iss_RelationDesc,
- node->scan.scanrelid,
node->indexqual,
false,
&indexstate->iss_ScanKeys,
*/
ExecIndexBuildScanKeys((PlanState *) indexstate,
indexstate->iss_RelationDesc,
- node->scan.scanrelid,
node->indexorderby,
true,
&indexstate->iss_OrderByKeys,
indexstate->iss_NumScanKeys,
indexstate->iss_NumOrderByKeys);
- /* Prepare for possible index-only scan */
- indexstate->iss_ScanDesc->xs_want_itup = node->indexonly;
- indexstate->iss_VMBuffer = InvalidBuffer;
-
/*
* If no run-time keys to calculate, go ahead and pass the scankeys to the
* index AM.
*
* planstate: executor state node we are working for
* index: the index we are building scan keys for
- * scanrelid: varno of the index's relation within current query
* 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
* ScalarArrayOpExpr quals are not supported.
*/
void
-ExecIndexBuildScanKeys(PlanState *planstate, Relation index, Index scanrelid,
+ExecIndexBuildScanKeys(PlanState *planstate, Relation index,
List *quals, bool isorderby,
ScanKey *scanKeys, int *numScanKeys,
IndexRuntimeKeyInfo **runtimeKeys, int *numRuntimeKeys,
Assert(leftop != NULL);
if (!(IsA(leftop, Var) &&
- ((Var *) leftop)->varno == scanrelid))
+ ((Var *) leftop)->varno == INDEX_VAR))
elog(ERROR, "indexqual doesn't have key on left side");
varattno = ((Var *) leftop)->varattno;
Assert(leftop != NULL);
if (!(IsA(leftop, Var) &&
- ((Var *) leftop)->varno == scanrelid))
+ ((Var *) leftop)->varno == INDEX_VAR))
elog(ERROR, "indexqual doesn't have key on left side");
varattno = ((Var *) leftop)->varattno;
Assert(leftop != NULL);
if (!(IsA(leftop, Var) &&
- ((Var *) leftop)->varno == scanrelid))
+ ((Var *) leftop)->varno == INDEX_VAR))
elog(ERROR, "indexqual doesn't have key on left side");
varattno = ((Var *) leftop)->varattno;
Assert(leftop != NULL);
if (!(IsA(leftop, Var) &&
- ((Var *) leftop)->varno == scanrelid))
+ ((Var *) leftop)->varno == INDEX_VAR))
elog(ERROR, "NullTest indexqual has wrong key");
varattno = ((Var *) leftop)->varattno;
ParamExecData *prm;
prm = &(econtext->ecxt_param_exec_vals[paramno]);
- /* Param value should be an OUTER var */
- Assert(nlp->paramval->varno == OUTER);
+ /* Param value should be an OUTER_VAR var */
+ Assert(nlp->paramval->varno == OUTER_VAR);
Assert(nlp->paramval->varattno > 0);
prm->value = slot_getattr(outerTupleSlot,
nlp->paramval->varattno,
COPY_NODE_FIELD(indexorderby);
COPY_NODE_FIELD(indexorderbyorig);
COPY_SCALAR_FIELD(indexorderdir);
- COPY_SCALAR_FIELD(indexonly);
+
+ return newnode;
+}
+
+/*
+ * _copyIndexOnlyScan
+ */
+static IndexOnlyScan *
+_copyIndexOnlyScan(IndexOnlyScan *from)
+{
+ IndexOnlyScan *newnode = makeNode(IndexOnlyScan);
+
+ /*
+ * copy node superclass fields
+ */
+ CopyScanFields((Scan *) from, (Scan *) newnode);
+
+ /*
+ * copy remainder of node
+ */
+ COPY_SCALAR_FIELD(indexid);
+ COPY_NODE_FIELD(indexqual);
+ COPY_NODE_FIELD(indexorderby);
+ COPY_NODE_FIELD(indextlist);
+ COPY_SCALAR_FIELD(indexorderdir);
return newnode;
}
case T_IndexScan:
retval = _copyIndexScan(from);
break;
+ case T_IndexOnlyScan:
+ retval = _copyIndexOnlyScan(from);
+ break;
case T_BitmapIndexScan:
retval = _copyBitmapIndexScan(from);
break;
WRITE_NODE_FIELD(indexorderby);
WRITE_NODE_FIELD(indexorderbyorig);
WRITE_ENUM_FIELD(indexorderdir, ScanDirection);
- WRITE_BOOL_FIELD(indexonly);
+}
+
+static void
+_outIndexOnlyScan(StringInfo str, IndexOnlyScan *node)
+{
+ WRITE_NODE_TYPE("INDEXONLYSCAN");
+
+ _outScanInfo(str, (Scan *) node);
+
+ WRITE_OID_FIELD(indexid);
+ WRITE_NODE_FIELD(indexqual);
+ WRITE_NODE_FIELD(indexorderby);
+ WRITE_NODE_FIELD(indextlist);
+ WRITE_ENUM_FIELD(indexorderdir, ScanDirection);
}
static void
WRITE_NODE_FIELD(indexorderbys);
WRITE_BOOL_FIELD(isjoininner);
WRITE_ENUM_FIELD(indexscandir, ScanDirection);
- WRITE_BOOL_FIELD(indexonly);
WRITE_FLOAT_FIELD(indextotalcost, "%.2f");
WRITE_FLOAT_FIELD(indexselectivity, "%.4f");
WRITE_FLOAT_FIELD(rows, "%.0f");
WRITE_FLOAT_FIELD(tuples, "%.0f");
WRITE_INT_FIELD(ncolumns);
WRITE_OID_FIELD(relam);
- WRITE_NODE_FIELD(indexprs);
+ /* indexprs is redundant since we print indextlist */
WRITE_NODE_FIELD(indpred);
+ WRITE_NODE_FIELD(indextlist);
WRITE_BOOL_FIELD(predOK);
WRITE_BOOL_FIELD(unique);
WRITE_BOOL_FIELD(hypothetical);
case T_IndexScan:
_outIndexScan(str, obj);
break;
+ case T_IndexOnlyScan:
+ _outIndexOnlyScan(str, obj);
+ break;
case T_BitmapIndexScan:
_outBitmapIndexScan(str, obj);
break;
switch (var->varno)
{
- case INNER:
+ case INNER_VAR:
relname = "INNER";
attname = "?";
break;
- case OUTER:
+ case OUTER_VAR:
relname = "OUTER";
attname = "?";
break;
+ case INDEX_VAR:
+ relname = "INDEX";
+ attname = "?";
+ break;
default:
{
RangeTblEntry *rte;
true, NULL, SAOP_FORBID, ST_ANYSCAN);
/*
- * Submit all the ones that can form plain IndexScan plans to add_path. (A
- * plain IndexPath always represents a plain IndexScan plan; however some
- * of the indexes might support only bitmap scans, and those we mustn't
- * submit to add_path here.) Also, pick out the ones that might be useful
- * as bitmap scans. For that, we must discard indexes that don't support
- * bitmap scans, and we also are only interested in paths that have some
- * selectivity; we should discard anything that was generated solely for
- * ordering purposes.
+ * Submit all the ones that can form plain IndexScan plans to add_path.
+ * (A plain IndexPath might represent either a plain IndexScan or an
+ * IndexOnlyScan, but for our purposes here the distinction does not
+ * matter. However, some of the indexes might support only bitmap scans,
+ * and those we mustn't submit to add_path here.) Also, pick out the ones
+ * that might be useful as bitmap scans. For that, we must discard
+ * indexes that don't support bitmap scans, and we also are only
+ * interested in paths that have some selectivity; we should discard
+ * anything that was generated solely for ordering purposes.
*/
bitindexpaths = NIL;
foreach(l, indexpaths)
/*
* For the moment, we just ignore index expressions. It might be nice
- * to do something with them, later. We also ignore index columns
- * that are system columns (such as OID), because the virtual-tuple
- * coding used by IndexStoreHeapTuple() can't deal with them.
+ * to do something with them, later.
*/
- if (attno <= 0)
+ if (attno == 0)
continue;
index_attrs =
#include "optimizer/pathnode.h"
#include "optimizer/paths.h"
#include "optimizer/tlist.h"
-#include "parser/parsetree.h"
#include "utils/lsyscache.h"
EquivalenceClass *eclass, Oid opfamily,
int strategy, bool nulls_first);
static bool pathkey_is_redundant(PathKey *new_pathkey, List *pathkeys);
-static Var *find_indexkey_var(PlannerInfo *root, RelOptInfo *rel,
- AttrNumber varattno);
static bool right_merge_direction(PlannerInfo *root, PathKey *pathkey);
ScanDirection scandir)
{
List *retval = NIL;
- ListCell *indexprs_item;
+ ListCell *lc;
int i;
if (index->sortopfamily == NULL)
return NIL; /* non-orderable index */
- indexprs_item = list_head(index->indexprs);
- for (i = 0; i < index->ncolumns; i++)
+ i = 0;
+ foreach(lc, index->indextlist)
{
+ TargetEntry *indextle = (TargetEntry *) lfirst(lc);
+ Expr *indexkey;
bool reverse_sort;
bool nulls_first;
- int ikey;
- Expr *indexkey;
PathKey *cpathkey;
+ /* We assume we don't need to make a copy of the tlist item */
+ indexkey = indextle->expr;
+
if (ScanDirectionIsBackward(scandir))
{
reverse_sort = !index->reverse_sort[i];
nulls_first = index->nulls_first[i];
}
- ikey = index->indexkeys[i];
- if (ikey != 0)
- {
- /* simple index column */
- indexkey = (Expr *) find_indexkey_var(root, index->rel, ikey);
- }
- else
- {
- /* expression --- assume we need not copy it */
- if (indexprs_item == NULL)
- elog(ERROR, "wrong number of index expressions");
- indexkey = (Expr *) lfirst(indexprs_item);
- indexprs_item = lnext(indexprs_item);
- }
-
/* OK, try to make a canonical pathkey for this sort key */
cpathkey = make_pathkey_from_sortinfo(root,
indexkey,
/* Add to list unless redundant */
if (!pathkey_is_redundant(cpathkey, retval))
retval = lappend(retval, cpathkey);
- }
- return retval;
-}
-
-/*
- * Find or make a Var node for the specified attribute of the rel.
- *
- * We first look for the var in the rel's target list, because that's
- * easy and fast. But the var might not be there (this should normally
- * only happen for vars that are used in WHERE restriction clauses,
- * but not in join clauses or in the SELECT target list). In that case,
- * gin up a Var node the hard way.
- */
-static Var *
-find_indexkey_var(PlannerInfo *root, RelOptInfo *rel, AttrNumber varattno)
-{
- ListCell *temp;
- Index relid;
- Oid reloid,
- vartypeid,
- varcollid;
- int32 type_mod;
-
- foreach(temp, rel->reltargetlist)
- {
- Var *var = (Var *) lfirst(temp);
-
- if (IsA(var, Var) &&
- var->varattno == varattno)
- return var;
+ i++;
}
- relid = rel->relid;
- reloid = getrelid(relid, root->parse->rtable);
- get_atttypetypmodcoll(reloid, varattno, &vartypeid, &type_mod, &varcollid);
-
- return makeVar(relid, varattno, vartypeid, type_mod, varcollid, 0);
+ return retval;
}
/*
static Plan *create_unique_plan(PlannerInfo *root, UniquePath *best_path);
static SeqScan *create_seqscan_plan(PlannerInfo *root, Path *best_path,
List *tlist, List *scan_clauses);
-static IndexScan *create_indexscan_plan(PlannerInfo *root, IndexPath *best_path,
- List *tlist, List *scan_clauses);
+static Scan *create_indexscan_plan(PlannerInfo *root, IndexPath *best_path,
+ List *tlist, List *scan_clauses, bool indexonly);
static BitmapHeapScan *create_bitmap_scan_plan(PlannerInfo *root,
BitmapHeapPath *best_path,
List *tlist, List *scan_clauses);
static IndexScan *make_indexscan(List *qptlist, List *qpqual, Index scanrelid,
Oid indexid, List *indexqual, List *indexqualorig,
List *indexorderby, List *indexorderbyorig,
- ScanDirection indexscandir, bool indexonly);
+ ScanDirection indexscandir);
+static IndexOnlyScan *make_indexonlyscan(List *qptlist, List *qpqual,
+ Index scanrelid, Oid indexid,
+ List *indexqual, List *indexorderby,
+ List *indextlist,
+ ScanDirection indexscandir);
static BitmapIndexScan *make_bitmap_indexscan(Index scanrelid, Oid indexid,
List *indexqual,
List *indexqualorig);
{
case T_SeqScan:
case T_IndexScan:
+ case T_IndexOnlyScan:
case T_BitmapHeapScan:
case T_TidScan:
case T_SubqueryScan:
*/
if (use_physical_tlist(root, rel))
{
- tlist = build_physical_tlist(root, rel);
- /* if fail because of dropped cols, use regular method */
- if (tlist == NIL)
- tlist = build_relation_tlist(rel);
+ if (best_path->pathtype == T_IndexOnlyScan)
+ {
+ /* For index-only scan, the preferred tlist is the index's */
+ tlist = copyObject(((IndexPath *) best_path)->indexinfo->indextlist);
+ }
+ else
+ {
+ tlist = build_physical_tlist(root, rel);
+ /* if fail because of dropped cols, use regular method */
+ if (tlist == NIL)
+ tlist = build_relation_tlist(rel);
+ }
}
else
tlist = build_relation_tlist(rel);
plan = (Plan *) create_indexscan_plan(root,
(IndexPath *) best_path,
tlist,
- scan_clauses);
+ scan_clauses,
+ false);
+ break;
+
+ case T_IndexOnlyScan:
+ plan = (Plan *) create_indexscan_plan(root,
+ (IndexPath *) best_path,
+ tlist,
+ scan_clauses,
+ true);
break;
case T_BitmapHeapScan:
{
case T_SeqScan:
case T_IndexScan:
+ case T_IndexOnlyScan:
case T_BitmapHeapScan:
case T_TidScan:
case T_SubqueryScan:
* Returns an indexscan plan for the base relation scanned by 'best_path'
* with restriction clauses 'scan_clauses' and targetlist 'tlist'.
*
+ * We use this for both plain IndexScans and IndexOnlyScans, because the
+ * qual preprocessing work is the same for both. Note that the caller tells
+ * us which to build --- we don't look at best_path->path.pathtype, because
+ * create_bitmap_subplan needs to be able to override the prior decision.
+ *
* The indexquals list of the path contains implicitly-ANDed qual conditions.
* The list can be empty --- then no index restrictions will be applied during
* the scan.
*/
-static IndexScan *
+static Scan *
create_indexscan_plan(PlannerInfo *root,
IndexPath *best_path,
List *tlist,
- List *scan_clauses)
+ List *scan_clauses,
+ bool indexonly)
{
+ Scan *scan_plan;
List *indexquals = best_path->indexquals;
List *indexorderbys = best_path->indexorderbys;
Index baserelid = best_path->path.parent->relid;
List *fixed_indexquals;
List *fixed_indexorderbys;
ListCell *l;
- IndexScan *scan_plan;
/* it should be a base rel... */
Assert(baserelid > 0);
/*
* The executor needs a copy with the indexkey on the left of each clause
- * and with index attr numbers substituted for table ones.
+ * and with index Vars substituted for table ones.
*/
fixed_indexquals = fix_indexqual_references(root, best_path, indexquals);
}
/* Finally ready to build the plan node */
- scan_plan = make_indexscan(tlist,
- qpqual,
- baserelid,
- indexoid,
- fixed_indexquals,
- stripped_indexquals,
- fixed_indexorderbys,
- indexorderbys,
- best_path->indexscandir,
- best_path->indexonly);
-
- copy_path_costsize(&scan_plan->scan.plan, &best_path->path);
+ if (indexonly)
+ scan_plan = (Scan *) make_indexonlyscan(tlist,
+ qpqual,
+ baserelid,
+ indexoid,
+ fixed_indexquals,
+ fixed_indexorderbys,
+ best_path->indexinfo->indextlist,
+ best_path->indexscandir);
+ else
+ scan_plan = (Scan *) make_indexscan(tlist,
+ qpqual,
+ baserelid,
+ indexoid,
+ fixed_indexquals,
+ stripped_indexquals,
+ fixed_indexorderbys,
+ indexorderbys,
+ best_path->indexscandir);
+
+ copy_path_costsize(&scan_plan->plan, &best_path->path);
/* use the indexscan-specific rows estimate, not the parent rel's */
- scan_plan->scan.plan.plan_rows = best_path->rows;
+ scan_plan->plan.plan_rows = best_path->rows;
return scan_plan;
}
ListCell *l;
/* Use the regular indexscan plan build machinery... */
- iscan = create_indexscan_plan(root, ipath, NIL, NIL);
+ iscan = (IndexScan *) create_indexscan_plan(root, ipath,
+ NIL, NIL, false);
+ Assert(IsA(iscan, IndexScan));
/* then convert to a bitmap indexscan */
plan = (Plan *) make_bitmap_indexscan(iscan->scan.scanrelid,
iscan->indexid,
/*
* fix_indexqual_operand
* Convert an indexqual expression to a Var referencing the index column.
+ *
+ * We represent index keys by Var nodes having varno == INDEX_VAR and varattno
+ * equal to the index's attribute number (index column position).
*/
static Node *
fix_indexqual_operand(Node *node, IndexOptInfo *index)
{
- /*
- * We represent index keys by Var nodes having the varno of the base table
- * but varattno equal to the index's attribute number (index column
- * position). This is a bit hokey ... would be cleaner to use a
- * special-purpose node type that could not be mistaken for a regular Var.
- * But it will do for now.
- */
Var *result;
int pos;
ListCell *indexpr_item;
if (index->indexkeys[pos] == varatt)
{
result = (Var *) copyObject(node);
+ result->varno = INDEX_VAR;
result->varattno = pos + 1;
return (Node *) result;
}
if (equal(node, indexkey))
{
/* Found a match */
- result = makeVar(index->rel->relid, pos + 1,
+ result = makeVar(INDEX_VAR, pos + 1,
exprType(lfirst(indexpr_item)), -1,
exprCollation(lfirst(indexpr_item)),
0);
List *indexqualorig,
List *indexorderby,
List *indexorderbyorig,
- ScanDirection indexscandir,
- bool indexonly)
+ ScanDirection indexscandir)
{
IndexScan *node = makeNode(IndexScan);
Plan *plan = &node->scan.plan;
node->indexorderby = indexorderby;
node->indexorderbyorig = indexorderbyorig;
node->indexorderdir = indexscandir;
- node->indexonly = indexonly;
+
+ return node;
+}
+
+static IndexOnlyScan *
+make_indexonlyscan(List *qptlist,
+ List *qpqual,
+ Index scanrelid,
+ Oid indexid,
+ List *indexqual,
+ List *indexorderby,
+ List *indextlist,
+ ScanDirection indexscandir)
+{
+ IndexOnlyScan *node = makeNode(IndexOnlyScan);
+ Plan *plan = &node->scan.plan;
+
+ /* cost should be inserted by caller */
+ plan->targetlist = qptlist;
+ plan->qual = qpqual;
+ plan->lefttree = NULL;
+ plan->righttree = NULL;
+ node->scan.scanrelid = scanrelid;
+ node->indexid = indexid;
+ node->indexqual = indexqual;
+ node->indexorderby = indexorderby;
+ node->indextlist = indextlist;
+ node->indexorderdir = indexscandir;
return node;
}
{
PlannerInfo *root;
indexed_tlist *subplan_itlist;
+ Index newvarno;
int rtoffset;
} fix_upper_expr_context;
((List *) fix_scan_expr(root, (Node *) (lst), rtoffset))
static Plan *set_plan_refs(PlannerInfo *root, Plan *plan, int rtoffset);
+static Plan *set_indexonlyscan_references(PlannerInfo *root,
+ IndexOnlyScan *plan,
+ int rtoffset);
static Plan *set_subqueryscan_references(PlannerInfo *root,
SubqueryScan *plan,
int rtoffset);
static Node *fix_upper_expr(PlannerInfo *root,
Node *node,
indexed_tlist *subplan_itlist,
+ Index newvarno,
int rtoffset);
static Node *fix_upper_expr_mutator(Node *node,
fix_upper_expr_context *context);
newrte->relid);
}
+ /*
+ * Check for RT index overflow; it's very unlikely, but if it did happen,
+ * the executor would get confused by varnos that match the special varno
+ * values.
+ */
+ if (IS_SPECIAL_VARNO(list_length(glob->finalrtable)))
+ ereport(ERROR,
+ (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
+ errmsg("too many range table entries")));
+
/*
* Adjust RT indexes of PlanRowMarks and add to final rowmarks list
*/
fix_scan_list(root, splan->indexorderbyorig, rtoffset);
}
break;
+ case T_IndexOnlyScan:
+ {
+ IndexOnlyScan *splan = (IndexOnlyScan *) plan;
+
+ return set_indexonlyscan_references(root, splan, rtoffset);
+ }
+ break;
case T_BitmapIndexScan:
{
BitmapIndexScan *splan = (BitmapIndexScan *) plan;
return plan;
}
+/*
+ * set_indexonlyscan_references
+ * Do set_plan_references processing on an IndexOnlyScan
+ *
+ * This is unlike the handling of a plain IndexScan because we have to
+ * convert Vars referencing the heap into Vars referencing the index.
+ * We can use the fix_upper_expr machinery for that, by working from a
+ * targetlist describing the index columns.
+ */
+static Plan *
+set_indexonlyscan_references(PlannerInfo *root,
+ IndexOnlyScan *plan,
+ int rtoffset)
+{
+ indexed_tlist *index_itlist;
+
+ index_itlist = build_tlist_index(plan->indextlist);
+
+ plan->scan.scanrelid += rtoffset;
+ plan->scan.plan.targetlist = (List *)
+ fix_upper_expr(root,
+ (Node *) plan->scan.plan.targetlist,
+ index_itlist,
+ INDEX_VAR,
+ rtoffset);
+ plan->scan.plan.qual = (List *)
+ fix_upper_expr(root,
+ (Node *) plan->scan.plan.qual,
+ index_itlist,
+ INDEX_VAR,
+ rtoffset);
+ /* indexqual is already transformed to reference index columns */
+ plan->indexqual = fix_scan_list(root, plan->indexqual, rtoffset);
+ /* indexorderby is already transformed to reference index columns */
+ plan->indexorderby = fix_scan_list(root, plan->indexorderby, rtoffset);
+ /* indextlist must NOT be transformed to reference index columns */
+ plan->indextlist = fix_scan_list(root, plan->indextlist, rtoffset);
+
+ pfree(index_itlist);
+
+ return (Plan *) plan;
+}
+
/*
* set_subqueryscan_references
* Do set_plan_references processing on a SubqueryScan
Assert(var->varlevelsup == 0);
/*
- * We should not see any Vars marked INNER or OUTER.
+ * We should not see any Vars marked INNER_VAR or OUTER_VAR. But an
+ * indexqual expression could contain INDEX_VAR Vars.
*/
- Assert(var->varno != INNER);
- Assert(var->varno != OUTER);
- var->varno += context->rtoffset;
+ Assert(var->varno != INNER_VAR);
+ Assert(var->varno != OUTER_VAR);
+ if (!IS_SPECIAL_VARNO(var->varno))
+ var->varno += context->rtoffset;
if (var->varnoold > 0)
var->varnoold += context->rtoffset;
return (Node *) var;
{
CurrentOfExpr *cexpr = (CurrentOfExpr *) copyObject(node);
- Assert(cexpr->cvarno != INNER);
- Assert(cexpr->cvarno != OUTER);
- cexpr->cvarno += context->rtoffset;
+ Assert(cexpr->cvarno != INNER_VAR);
+ Assert(cexpr->cvarno != OUTER_VAR);
+ if (!IS_SPECIAL_VARNO(cexpr->cvarno))
+ cexpr->cvarno += context->rtoffset;
return (Node *) cexpr;
}
if (IsA(node, PlaceHolderVar))
/*
* set_join_references
* Modify the target list and quals of a join node to reference its
- * subplans, by setting the varnos to OUTER or INNER and setting attno
- * values to the result domain number of either the corresponding outer
- * or inner join tuple item. Also perform opcode lookup for these
+ * subplans, by setting the varnos to OUTER_VAR or INNER_VAR and setting
+ * attno values to the result domain number of either the corresponding
+ * outer or inner join tuple item. Also perform opcode lookup for these
* expressions. and add regclass OIDs to root->glob->relationOids.
*/
static void
nlp->paramval = (Var *) fix_upper_expr(root,
(Node *) nlp->paramval,
outer_itlist,
+ OUTER_VAR,
rtoffset);
}
}
search_indexed_tlist_for_sortgroupref((Node *) tle->expr,
tle->ressortgroupref,
subplan_itlist,
- OUTER);
+ OUTER_VAR);
if (!newexpr)
newexpr = fix_upper_expr(root,
(Node *) tle->expr,
subplan_itlist,
+ OUTER_VAR,
rtoffset);
}
else
newexpr = fix_upper_expr(root,
(Node *) tle->expr,
subplan_itlist,
+ OUTER_VAR,
rtoffset);
tle = flatCopyTargetEntry(tle);
tle->expr = (Expr *) newexpr;
fix_upper_expr(root,
(Node *) plan->qual,
subplan_itlist,
+ OUTER_VAR,
rtoffset);
pfree(subplan_itlist);
/*
* set_dummy_tlist_references
* Replace the targetlist of an upper-level plan node with a simple
- * list of OUTER references to its child.
+ * list of OUTER_VAR references to its child.
*
* This is used for plan types like Sort and Append that don't evaluate
* their targetlists. Although the executor doesn't care at all what's in
Var *oldvar = (Var *) tle->expr;
Var *newvar;
- newvar = makeVar(OUTER,
+ newvar = makeVar(OUTER_VAR,
tle->resno,
exprType((Node *) oldvar),
exprTypmod((Node *) oldvar),
* relation target lists. Also perform opcode lookup and add
* regclass OIDs to root->glob->relationOids.
*
- * This is used in two different scenarios: a normal join clause, where
- * all the Vars in the clause *must* be replaced by OUTER or INNER references;
- * and a RETURNING clause, which may contain both Vars of the target relation
- * and Vars of other relations. In the latter case we want to replace the
- * other-relation Vars by OUTER references, while leaving target Vars alone.
+ * This is used in two different scenarios: a normal join clause, where all
+ * the Vars in the clause *must* be replaced by OUTER_VAR or INNER_VAR
+ * references; and a RETURNING clause, which may contain both Vars of the
+ * target relation and Vars of other relations. In the latter case we want
+ * to replace the other-relation Vars by OUTER_VAR references, while leaving
+ * target Vars alone.
*
* For a normal join, acceptable_rel should be zero so that any failure to
* match a Var will be reported as an error. For the RETURNING case, pass
/* First look for the var in the input tlists */
newvar = search_indexed_tlist_for_var(var,
context->outer_itlist,
- OUTER,
+ OUTER_VAR,
context->rtoffset);
if (newvar)
return (Node *) newvar;
{
newvar = search_indexed_tlist_for_var(var,
context->inner_itlist,
- INNER,
+ INNER_VAR,
context->rtoffset);
if (newvar)
return (Node *) newvar;
{
newvar = search_indexed_tlist_for_non_var((Node *) phv,
context->outer_itlist,
- OUTER);
+ OUTER_VAR);
if (newvar)
return (Node *) newvar;
}
{
newvar = search_indexed_tlist_for_non_var((Node *) phv,
context->inner_itlist,
- INNER);
+ INNER_VAR);
if (newvar)
return (Node *) newvar;
}
{
newvar = search_indexed_tlist_for_non_var(node,
context->outer_itlist,
- OUTER);
+ OUTER_VAR);
if (newvar)
return (Node *) newvar;
}
{
newvar = search_indexed_tlist_for_non_var(node,
context->inner_itlist,
- INNER);
+ INNER_VAR);
if (newvar)
return (Node *) newvar;
}
* root->glob->relationOids.
*
* This is used to fix up target and qual expressions of non-join upper-level
- * plan nodes.
+ * plan nodes, as well as index-only scan nodes.
*
* An error is raised if no matching var can be found in the subplan tlist
* --- so this routine should only be applied to nodes whose subplans'
* subplan tlist is just a flattened list of Vars.)
*
* 'node': the tree to be fixed (a target item or qual)
- * 'subplan_itlist': indexed target list for subplan
+ * 'subplan_itlist': indexed target list for subplan (or index)
+ * 'newvarno': varno to use for Vars referencing tlist elements
* 'rtoffset': how much to increment varnoold by
*
* The resulting tree is a copy of the original in which all Var nodes have
- * varno = OUTER, varattno = resno of corresponding subplan target.
+ * varno = newvarno, varattno = resno of corresponding targetlist element.
* The original tree is not modified.
*/
static Node *
fix_upper_expr(PlannerInfo *root,
Node *node,
indexed_tlist *subplan_itlist,
+ Index newvarno,
int rtoffset)
{
fix_upper_expr_context context;
context.root = root;
context.subplan_itlist = subplan_itlist;
+ context.newvarno = newvarno;
context.rtoffset = rtoffset;
return fix_upper_expr_mutator(node, &context);
}
newvar = search_indexed_tlist_for_var(var,
context->subplan_itlist,
- OUTER,
+ context->newvarno,
context->rtoffset);
if (!newvar)
elog(ERROR, "variable not found in subplan target list");
{
newvar = search_indexed_tlist_for_non_var((Node *) phv,
context->subplan_itlist,
- OUTER);
+ context->newvarno);
if (newvar)
return (Node *) newvar;
}
{
newvar = search_indexed_tlist_for_non_var(node,
context->subplan_itlist,
- OUTER);
+ context->newvarno);
if (newvar)
return (Node *) newvar;
}
* table should be left alone, however (the executor will evaluate them
* using the actual heap tuple, after firing triggers if any). In the
* adjusted RETURNING list, result-table Vars will still have their
- * original varno, but Vars for other rels will have varno OUTER.
+ * original varno, but Vars for other rels will have varno OUTER_VAR.
*
* We also must perform opcode lookup and add regclass OIDs to
* root->glob->relationOids.
context.paramids = bms_add_members(context.paramids, scan_params);
break;
+ case T_IndexOnlyScan:
+ finalize_primnode((Node *) ((IndexOnlyScan *) plan)->indexqual,
+ &context);
+ finalize_primnode((Node *) ((IndexOnlyScan *) plan)->indexorderby,
+ &context);
+
+ /*
+ * we need not look at indextlist, since it cannot contain Params.
+ */
+ context.paramids = bms_add_members(context.paramids, scan_params);
+ break;
+
case T_BitmapIndexScan:
finalize_primnode((Node *) ((BitmapIndexScan *) plan)->indexqual,
&context);
indexscandir = NoMovementScanDirection;
}
- pathnode->path.pathtype = T_IndexScan;
+ pathnode->path.pathtype = indexonly ? T_IndexOnlyScan : T_IndexScan;
pathnode->path.parent = rel;
pathnode->path.pathkeys = pathkeys;
pathnode->isjoininner = (outer_rel != NULL);
pathnode->indexscandir = indexscandir;
- pathnode->indexonly = indexonly;
if (outer_rel != NULL)
{
#include "access/sysattr.h"
#include "access/transam.h"
#include "catalog/catalog.h"
+#include "catalog/heap.h"
#include "miscadmin.h"
#include "nodes/makefuncs.h"
#include "optimizer/clauses.h"
static List *get_relation_constraints(PlannerInfo *root,
Oid relationObjectId, RelOptInfo *rel,
bool include_notnull);
+static List *build_index_tlist(PlannerInfo *root, IndexOptInfo *index,
+ Relation heapRelation);
/*
ChangeVarNodes((Node *) info->indexprs, 1, varno, 0);
if (info->indpred && varno != 1)
ChangeVarNodes((Node *) info->indpred, 1, varno, 0);
+
+ /* Build targetlist using the completed indexprs data */
+ info->indextlist = build_index_tlist(root, info, relation);
+
info->predOK = false; /* set later in indxpath.c */
info->unique = index->indisunique;
info->hypothetical = false;
return tlist;
}
+/*
+ * build_index_tlist
+ *
+ * Build a targetlist representing the columns of the specified index.
+ * Each column is represented by a Var for the corresponding base-relation
+ * column, or an expression in base-relation Vars, as appropriate.
+ *
+ * There are never any dropped columns in indexes, so unlike
+ * build_physical_tlist, we need no failure case.
+ */
+static List *
+build_index_tlist(PlannerInfo *root, IndexOptInfo *index,
+ Relation heapRelation)
+{
+ List *tlist = NIL;
+ Index varno = index->rel->relid;
+ ListCell *indexpr_item;
+ int i;
+
+ indexpr_item = list_head(index->indexprs);
+ for (i = 0; i < index->ncolumns; i++)
+ {
+ int indexkey = index->indexkeys[i];
+ Expr *indexvar;
+
+ if (indexkey != 0)
+ {
+ /* simple column */
+ Form_pg_attribute att_tup;
+
+ if (indexkey < 0)
+ att_tup = SystemAttributeDefinition(indexkey,
+ heapRelation->rd_rel->relhasoids);
+ else
+ att_tup = heapRelation->rd_att->attrs[indexkey - 1];
+
+ indexvar = (Expr *) makeVar(varno,
+ indexkey,
+ att_tup->atttypid,
+ att_tup->atttypmod,
+ att_tup->attcollation,
+ 0);
+ }
+ else
+ {
+ /* expression column */
+ if (indexpr_item == NULL)
+ elog(ERROR, "wrong number of index expressions");
+ indexvar = (Expr *) lfirst(indexpr_item);
+ indexpr_item = lnext(indexpr_item);
+ }
+
+ tlist = lappend(tlist,
+ makeTargetEntry(indexvar,
+ i + 1,
+ NULL,
+ false));
+ }
+ if (indexpr_item != NULL)
+ elog(ERROR, "wrong number of index expressions");
+
+ return tlist;
+}
+
/*
* restriction_selectivity
*
* deparse_namespace list (since a plan tree never contains Vars with
* varlevelsup > 0). We store the PlanState node that is the immediate
* parent of the expression to be deparsed, as well as a list of that
- * PlanState's ancestors. In addition, we store the outer and inner
- * subplan nodes, whose targetlists are used to resolve OUTER and INNER Vars.
- * (Note: these could be derived on-the-fly from the planstate instead.)
+ * PlanState's ancestors. In addition, we store its outer and inner subplan
+ * state nodes, as well as their plan nodes' targetlists, and the indextlist
+ * if the current PlanState is an IndexOnlyScanState. (These fields could
+ * be derived on-the-fly from the current PlanState, but it seems notationally
+ * clearer to set them up as separate fields.)
*/
typedef struct
{
/* Remaining fields are used only when deparsing a Plan tree: */
PlanState *planstate; /* immediate parent of current expression */
List *ancestors; /* ancestors of planstate */
- PlanState *outer_planstate; /* OUTER subplan state, or NULL if none */
- PlanState *inner_planstate; /* INNER subplan state, or NULL if none */
- Plan *outer_plan; /* OUTER subplan, or NULL if none */
- Plan *inner_plan; /* INNER subplan, or NULL if none */
+ PlanState *outer_planstate; /* outer subplan state, or NULL if none */
+ PlanState *inner_planstate; /* inner subplan state, or NULL if none */
+ List *outer_tlist; /* referent for OUTER_VAR Vars */
+ List *inner_tlist; /* referent for INNER_VAR Vars */
+ List *index_tlist; /* referent for INDEX_VAR Vars */
} deparse_namespace;
* deparse_context_for_planstate - Build deparse context for a plan
*
* When deparsing an expression in a Plan tree, we might have to resolve
- * OUTER or INNER references. To do this, the caller must provide the
- * parent PlanState node. Then OUTER and INNER references can be resolved
- * by drilling down into the left and right child plans.
+ * OUTER_VAR, INNER_VAR, or INDEX_VAR references. To do this, the caller must
+ * provide the parent PlanState node. Then OUTER_VAR and INNER_VAR references
+ * can be resolved by drilling down into the left and right child plans.
+ * Similarly, INDEX_VAR references can be resolved by reference to the
+ * indextlist given in the parent IndexOnlyScan node. (Note that we don't
+ * currently support deparsing of indexquals in regular IndexScan or
+ * BitmapIndexScan nodes; for those, we can only deparse the indexqualorig
+ * fields, which won't contain INDEX_VAR Vars.)
*
* Note: planstate really ought to be declared as "PlanState *", but we use
* "Node *" to avoid having to include execnodes.h in builtins.h.
*
* The plan's rangetable list must also be passed. We actually prefer to use
* the rangetable to resolve simple Vars, but the plan inputs are necessary
- * for Vars that reference expressions computed in subplan target lists.
+ * for Vars with special varnos.
*/
List *
deparse_context_for_planstate(Node *planstate, List *ancestors,
* set_deparse_planstate: set up deparse_namespace to parse subexpressions
* of a given PlanState node
*
- * This sets the planstate, outer_planstate, inner_planstate, outer_plan, and
- * inner_plan fields. Caller is responsible for adjusting the ancestors list
- * if necessary. Note that the rtable and ctes fields do not need to change
- * when shifting attention to different plan nodes in a single plan tree.
+ * This sets the planstate, outer_planstate, inner_planstate, outer_tlist,
+ * inner_tlist, and index_tlist fields. Caller is responsible for adjusting
+ * the ancestors list if necessary. Note that the rtable and ctes fields do
+ * not need to change when shifting attention to different plan nodes in a
+ * single plan tree.
*/
static void
set_deparse_planstate(deparse_namespace *dpns, PlanState *ps)
dpns->outer_planstate = outerPlanState(ps);
if (dpns->outer_planstate)
- dpns->outer_plan = dpns->outer_planstate->plan;
+ dpns->outer_tlist = dpns->outer_planstate->plan->targetlist;
else
- dpns->outer_plan = NULL;
+ dpns->outer_tlist = NIL;
/*
* For a SubqueryScan, pretend the subplan is INNER referent. (We don't
dpns->inner_planstate = innerPlanState(ps);
if (dpns->inner_planstate)
- dpns->inner_plan = dpns->inner_planstate->plan;
+ dpns->inner_tlist = dpns->inner_planstate->plan->targetlist;
else
- dpns->inner_plan = NULL;
+ dpns->inner_tlist = NIL;
+
+ /* index_tlist is set only if it's an IndexOnlyScan */
+ if (IsA(ps->plan, IndexOnlyScan))
+ dpns->index_tlist = ((IndexOnlyScan *) ps->plan)->indextlist;
+ else
+ dpns->index_tlist = NIL;
}
/*
* push_child_plan: temporarily transfer deparsing attention to a child plan
*
- * When expanding an OUTER or INNER reference, we must adjust the deparse
- * context in case the referenced expression itself uses OUTER/INNER. We
- * modify the top stack entry in-place to avoid affecting levelsup issues
- * (although in a Plan tree there really shouldn't be any).
+ * When expanding an OUTER_VAR or INNER_VAR reference, we must adjust the
+ * deparse context in case the referenced expression itself uses
+ * OUTER_VAR/INNER_VAR. We modify the top stack entry in-place to avoid
+ * affecting levelsup issues (although in a Plan tree there really shouldn't
+ * be any).
*
* Caller must provide a local deparse_namespace variable to save the
* previous state for pop_child_plan.
/*
* Currently we don't bother to adjust the ancestors list, because an
- * OUTER or INNER reference really shouldn't contain any Params that would
- * be set by the parent node itself. If we did want to adjust it,
- * lcons'ing dpns->planstate onto dpns->ancestors would be the appropriate
- * thing --- and pop_child_plan would need to undo the change to the list.
+ * OUTER_VAR or INNER_VAR reference really shouldn't contain any Params
+ * that would be set by the parent node itself. If we did want to adjust
+ * the list, lcons'ing dpns->planstate onto dpns->ancestors would be the
+ * appropriate thing --- and pop_child_plan would need to undo the change
+ * to the list.
*/
/* Set attention on selected child */
* When expanding a Param reference, we must adjust the deparse context
* to match the plan node that contains the expression being printed;
* otherwise we'd fail if that expression itself contains a Param or
- * OUTER/INNER variables.
+ * OUTER_VAR/INNER_VAR/INDEX_VAR variable.
*
* The target ancestor is conveniently identified by the ListCell holding it
* in dpns->ancestors.
/*
* Try to find the relevant RTE in this rtable. In a plan tree, it's
- * likely that varno is OUTER or INNER, in which case we must dig down
- * into the subplans.
+ * likely that varno is OUTER_VAR or INNER_VAR, in which case we must dig
+ * down into the subplans, or INDEX_VAR, which is resolved similarly.
*/
if (var->varno >= 1 && var->varno <= list_length(dpns->rtable))
{
rte = rt_fetch(var->varno, dpns->rtable);
attnum = var->varattno;
}
- else if (var->varno == OUTER && dpns->outer_plan)
+ else if (var->varno == OUTER_VAR && dpns->outer_tlist)
{
TargetEntry *tle;
deparse_namespace save_dpns;
- tle = get_tle_by_resno(dpns->outer_plan->targetlist, var->varattno);
+ tle = get_tle_by_resno(dpns->outer_tlist, var->varattno);
if (!tle)
- elog(ERROR, "bogus varattno for OUTER var: %d", var->varattno);
+ elog(ERROR, "bogus varattno for OUTER_VAR var: %d", var->varattno);
Assert(netlevelsup == 0);
push_child_plan(dpns, dpns->outer_planstate, &save_dpns);
pop_child_plan(dpns, &save_dpns);
return NULL;
}
- else if (var->varno == INNER && dpns->inner_plan)
+ else if (var->varno == INNER_VAR && dpns->inner_tlist)
{
TargetEntry *tle;
deparse_namespace save_dpns;
- tle = get_tle_by_resno(dpns->inner_plan->targetlist, var->varattno);
+ tle = get_tle_by_resno(dpns->inner_tlist, var->varattno);
if (!tle)
- elog(ERROR, "bogus varattno for INNER var: %d", var->varattno);
+ elog(ERROR, "bogus varattno for INNER_VAR var: %d", var->varattno);
Assert(netlevelsup == 0);
push_child_plan(dpns, dpns->inner_planstate, &save_dpns);
pop_child_plan(dpns, &save_dpns);
return NULL;
}
+ else if (var->varno == INDEX_VAR && dpns->index_tlist)
+ {
+ TargetEntry *tle;
+
+ tle = get_tle_by_resno(dpns->index_tlist, var->varattno);
+ if (!tle)
+ elog(ERROR, "bogus varattno for INDEX_VAR var: %d", var->varattno);
+
+ Assert(netlevelsup == 0);
+
+ /*
+ * Force parentheses because our caller probably assumed a Var is a
+ * simple expression.
+ */
+ if (!IsA(tle->expr, Var))
+ appendStringInfoChar(buf, '(');
+ get_rule_expr((Node *) tle->expr, context, true);
+ if (!IsA(tle->expr, Var))
+ appendStringInfoChar(buf, ')');
+
+ return NULL;
+ }
else
{
elog(ERROR, "bogus varno: %d", var->varno);
* no alias. So in that case, drill down to the subplan and print the
* contents of the referenced tlist item. This works because in a plan
* tree, such Vars can only occur in a SubqueryScan or CteScan node, and
- * we'll have set dpns->inner_plan to reference the child plan node.
+ * we'll have set dpns->inner_planstate to reference the child plan node.
*/
if ((rte->rtekind == RTE_SUBQUERY || rte->rtekind == RTE_CTE) &&
attnum > list_length(rte->eref->colnames) &&
- dpns->inner_plan)
+ dpns->inner_planstate)
{
TargetEntry *tle;
deparse_namespace save_dpns;
- tle = get_tle_by_resno(dpns->inner_plan->targetlist, var->varattno);
+ tle = get_tle_by_resno(dpns->inner_tlist, var->varattno);
if (!tle)
elog(ERROR, "bogus varattno for subquery var: %d", var->varattno);
/*
* Try to find the relevant RTE in this rtable. In a plan tree, it's
- * likely that varno is OUTER or INNER, in which case we must dig down
- * into the subplans.
+ * likely that varno is OUTER_VAR or INNER_VAR, in which case we must dig
+ * down into the subplans, or INDEX_VAR, which is resolved similarly.
*/
if (var->varno >= 1 && var->varno <= list_length(dpns->rtable))
{
rte = rt_fetch(var->varno, dpns->rtable);
attnum = var->varattno;
}
- else if (var->varno == OUTER && dpns->outer_plan)
+ else if (var->varno == OUTER_VAR && dpns->outer_tlist)
{
TargetEntry *tle;
deparse_namespace save_dpns;
const char *result;
- tle = get_tle_by_resno(dpns->outer_plan->targetlist, var->varattno);
+ tle = get_tle_by_resno(dpns->outer_tlist, var->varattno);
if (!tle)
- elog(ERROR, "bogus varattno for OUTER var: %d", var->varattno);
+ elog(ERROR, "bogus varattno for OUTER_VAR var: %d", var->varattno);
Assert(netlevelsup == 0);
push_child_plan(dpns, dpns->outer_planstate, &save_dpns);
pop_child_plan(dpns, &save_dpns);
return result;
}
- else if (var->varno == INNER && dpns->inner_plan)
+ else if (var->varno == INNER_VAR && dpns->inner_tlist)
{
TargetEntry *tle;
deparse_namespace save_dpns;
const char *result;
- tle = get_tle_by_resno(dpns->inner_plan->targetlist, var->varattno);
+ tle = get_tle_by_resno(dpns->inner_tlist, var->varattno);
if (!tle)
- elog(ERROR, "bogus varattno for INNER var: %d", var->varattno);
+ elog(ERROR, "bogus varattno for INNER_VAR var: %d", var->varattno);
Assert(netlevelsup == 0);
push_child_plan(dpns, dpns->inner_planstate, &save_dpns);
pop_child_plan(dpns, &save_dpns);
return result;
}
+ else if (var->varno == INDEX_VAR && dpns->index_tlist)
+ {
+ TargetEntry *tle;
+ const char *result;
+
+ tle = get_tle_by_resno(dpns->index_tlist, var->varattno);
+ if (!tle)
+ elog(ERROR, "bogus varattno for INDEX_VAR var: %d", var->varattno);
+
+ Assert(netlevelsup == 0);
+
+ result = get_name_for_var_field((Var *) tle->expr, fieldno,
+ levelsup, context);
+
+ return result;
+ }
else
{
elog(ERROR, "bogus varno: %d", var->varno);
deparse_namespace save_dpns;
const char *result;
- if (!dpns->inner_plan)
+ if (!dpns->inner_planstate)
elog(ERROR, "failed to find plan for subquery %s",
rte->eref->aliasname);
- tle = get_tle_by_resno(dpns->inner_plan->targetlist,
- attnum);
+ tle = get_tle_by_resno(dpns->inner_tlist, attnum);
if (!tle)
elog(ERROR, "bogus varattno for subquery var: %d",
attnum);
deparse_namespace save_dpns;
const char *result;
- if (!dpns->inner_plan)
+ if (!dpns->inner_planstate)
elog(ERROR, "failed to find plan for CTE %s",
rte->eref->aliasname);
- tle = get_tle_by_resno(dpns->inner_plan->targetlist,
- attnum);
+ tle = get_tle_by_resno(dpns->inner_tlist, attnum);
if (!tle)
elog(ERROR, "bogus varattno for subquery var: %d",
attnum);
Var *var = (Var *) tle->expr;
RangeTblEntry *rte;
- if (var->varno > 0 && var->varno < INNER &&
+ if (!IS_SPECIAL_VARNO(var->varno) &&
var->varattno == SelfItemPointerAttributeNumber)
{
rte = rt_fetch(var->varno, query->rtable);
--- /dev/null
+/*-------------------------------------------------------------------------
+ *
+ * nodeIndexonlyscan.h
+ *
+ *
+ *
+ * Portions Copyright (c) 1996-2011, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/include/executor/nodeIndexonlyscan.h
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef NODEINDEXONLYSCAN_H
+#define NODEINDEXONLYSCAN_H
+
+#include "nodes/execnodes.h"
+
+extern IndexOnlyScanState *ExecInitIndexOnlyScan(IndexOnlyScan *node, EState *estate, int eflags);
+extern TupleTableSlot *ExecIndexOnlyScan(IndexOnlyScanState *node);
+extern void ExecEndIndexOnlyScan(IndexOnlyScanState *node);
+extern void ExecIndexOnlyMarkPos(IndexOnlyScanState *node);
+extern void ExecIndexOnlyRestrPos(IndexOnlyScanState *node);
+extern void ExecReScanIndexOnlyScan(IndexOnlyScanState *node);
+
+#endif /* NODEINDEXONLYSCAN_H */
extern void ExecIndexRestrPos(IndexScanState *node);
extern void ExecReScanIndexScan(IndexScanState *node);
-/* routines exported to share code with nodeBitmapIndexscan.c */
+/*
+ * These routines are exported to share code with nodeIndexonlyscan.c and
+ * nodeBitmapIndexscan.c
+ */
extern void ExecIndexBuildScanKeys(PlanState *planstate, Relation index,
- Index scanrelid, List *quals, bool isorderby,
+ List *quals, bool isorderby,
ScanKey *scanKeys, int *numScanKeys,
IndexRuntimeKeyInfo **runtimeKeys, int *numRuntimeKeys,
IndexArrayKeyInfo **arrayKeys, int *numArrayKeys);
* RuntimeContext expr context for evaling runtime Skeys
* RelationDesc index relation descriptor
* ScanDesc index scan descriptor
- * VMBuffer buffer in use for visibility map testing, if any
* ----------------
*/
typedef struct IndexScanState
ExprContext *iss_RuntimeContext;
Relation iss_RelationDesc;
IndexScanDesc iss_ScanDesc;
- Buffer iss_VMBuffer;
} IndexScanState;
+/* ----------------
+ * IndexOnlyScanState information
+ *
+ * indexqual execution state for indexqual expressions
+ * ScanKeys Skey structures for index quals
+ * NumScanKeys number of ScanKeys
+ * OrderByKeys Skey structures for index ordering operators
+ * NumOrderByKeys number of OrderByKeys
+ * RuntimeKeys info about Skeys that must be evaluated at runtime
+ * NumRuntimeKeys number of RuntimeKeys
+ * RuntimeKeysReady true if runtime Skeys have been computed
+ * RuntimeContext expr context for evaling runtime Skeys
+ * RelationDesc index relation descriptor
+ * ScanDesc index scan descriptor
+ * VMBuffer buffer in use for visibility map testing, if any
+ * ----------------
+ */
+typedef struct IndexOnlyScanState
+{
+ ScanState ss; /* its first field is NodeTag */
+ List *indexqual;
+ ScanKey ioss_ScanKeys;
+ int ioss_NumScanKeys;
+ ScanKey ioss_OrderByKeys;
+ int ioss_NumOrderByKeys;
+ IndexRuntimeKeyInfo *ioss_RuntimeKeys;
+ int ioss_NumRuntimeKeys;
+ bool ioss_RuntimeKeysReady;
+ ExprContext *ioss_RuntimeContext;
+ Relation ioss_RelationDesc;
+ IndexScanDesc ioss_ScanDesc;
+ Buffer ioss_VMBuffer;
+} IndexOnlyScanState;
+
/* ----------------
* BitmapIndexScanState information
*
T_Scan,
T_SeqScan,
T_IndexScan,
+ T_IndexOnlyScan,
T_BitmapIndexScan,
T_BitmapHeapScan,
T_TidScan,
T_ScanState,
T_SeqScanState,
T_IndexScanState,
+ T_IndexOnlyScanState,
T_BitmapIndexScanState,
T_BitmapHeapScanState,
T_TidScanState,
*
* indexqual has the same form, but the expressions have been commuted if
* necessary to put the indexkeys on the left, and the indexkeys are replaced
- * by Var nodes identifying the index columns (varattno is the index column
- * position, not the base table's column, even though varno is for the base
- * table). This is a bit hokey ... would be cleaner to use a special-purpose
- * node type that could not be mistaken for a regular Var. But it will do
- * for now.
+ * by Var nodes identifying the index columns (their varno is INDEX_VAR and
+ * their varattno is the index column number).
*
* indexorderbyorig is similarly the original form of any ORDER BY expressions
* that are being implemented by the index, while indexorderby is modified to
* (Note these fields are used for amcanorderbyop cases, not amcanorder cases.)
*
* indexorderdir specifies the scan ordering, for indexscans on amcanorder
- * indexes (for other indexes it should be "don't care"). indexonly specifies
- * an index-only scan, for indexscans on amcanreturn indexes.
+ * indexes (for other indexes it should be "don't care").
* ----------------
*/
typedef struct IndexScan
List *indexorderby; /* list of index ORDER BY exprs */
List *indexorderbyorig; /* the same in original form */
ScanDirection indexorderdir; /* forward or backward or don't care */
- bool indexonly; /* attempt to skip heap fetches? */
} IndexScan;
+/* ----------------
+ * index-only scan node
+ *
+ * IndexOnlyScan is very similar to IndexScan, but it specifies an
+ * index-only scan, in which the data comes from the index not the heap.
+ * Because of this, *all* Vars in the plan node's targetlist, qual, and
+ * index expressions reference index columns and have varno = INDEX_VAR.
+ * Hence we do not need separate indexqualorig and indexorderbyorig lists,
+ * since their contents would be equivalent to indexqual and indexorderby.
+ *
+ * To help EXPLAIN interpret the index Vars for display, we provide
+ * indextlist, which represents the contents of the index as a targetlist
+ * with one TLE per index column. Vars appearing in this list reference
+ * the base table, and this is the only field in the plan node that may
+ * contain such Vars.
+ * ----------------
+ */
+typedef struct IndexOnlyScan
+{
+ Scan scan;
+ Oid indexid; /* OID of index to scan */
+ List *indexqual; /* list of index quals (usually OpExprs) */
+ List *indexorderby; /* list of index ORDER BY exprs */
+ List *indextlist; /* TargetEntry list describing index's cols */
+ ScanDirection indexorderdir; /* forward or backward or don't care */
+} IndexOnlyScan;
+
/* ----------------
* bitmap index scan node
*
* Note: during parsing/planning, varnoold/varoattno are always just copies
* of varno/varattno. At the tail end of planning, Var nodes appearing in
* upper-level plan nodes are reassigned to point to the outputs of their
- * subplans; for example, in a join node varno becomes INNER or OUTER and
- * varattno becomes the index of the proper element of that subplan's target
- * list. But varnoold/varoattno continue to hold the original values.
+ * subplans; for example, in a join node varno becomes INNER_VAR or OUTER_VAR
+ * and varattno becomes the index of the proper element of that subplan's
+ * target list. But varnoold/varoattno continue to hold the original values.
* The code doesn't really need varnoold/varoattno, but they are very useful
* for debugging and interpreting completed plans, so we keep them around.
*/
-#define INNER 65000
-#define OUTER 65001
+#define INNER_VAR 65000 /* reference to inner subplan */
+#define OUTER_VAR 65001 /* reference to outer subplan */
+#define INDEX_VAR 65002 /* reference to index column */
+#define IS_SPECIAL_VARNO(varno) ((varno) >= INNER_VAR)
+
+/* Symbols for the indexes of the special RTE entries in rules */
#define PRS2_OLD_VARNO 1
#define PRS2_NEW_VARNO 2
{
Expr xpr;
Index varno; /* index of this var's relation in the range
- * table (could also be INNER or OUTER) */
+ * table, or INNER_VAR/OUTER_VAR/INDEX_VAR */
AttrNumber varattno; /* attribute number of this var, or zero for
* all */
Oid vartype; /* pg_type OID for the type of this var */
* The indexprs and indpred expressions have been run through
* prepqual.c and eval_const_expressions() for ease of matching to
* WHERE clauses. indpred is in implicit-AND form.
+ *
+ * indextlist is a TargetEntry list representing the index columns.
+ * It provides an equivalent base-relation Var for each simple column,
+ * and links to the matching indexprs element for each expression column.
*/
typedef struct IndexOptInfo
{
List *indexprs; /* expressions for non-simple index columns */
List *indpred; /* predicate if a partial index, else NIL */
+ List *indextlist; /* targetlist representing index columns */
+
bool predOK; /* true if predicate matches query */
bool unique; /* true if a unique index */
bool hypothetical; /* true if index doesn't really exist */
/*----------
* IndexPath represents an index scan over a single index.
*
+ * This struct is used for both regular indexscans and index-only scans;
+ * path.pathtype is T_IndexScan or T_IndexOnlyScan to show which is meant.
+ *
* 'indexinfo' is the index to be scanned.
*
* 'indexclauses' is a list of index qualification clauses, with implicit
* NoMovementScanDirection for an indexscan, but the planner wants to
* distinguish ordered from unordered indexes for building pathkeys.)
*
- * 'indexonly' is TRUE for an index-only scan, that is, the index's access
- * method has amcanreturn = TRUE and we only need columns available from the
- * index.
- *
* 'indextotalcost' and 'indexselectivity' are saved in the IndexPath so that
* we need not recompute them when considering using the same index in a
* bitmap index/heap scan (see BitmapHeapPath). The costs of the IndexPath
- * itself represent the costs of an IndexScan plan type.
+ * itself represent the costs of an IndexScan or IndexOnlyScan plan type.
*
* 'rows' is the estimated result tuple count for the indexscan. This
* is the same as path.parent->rows for a simple indexscan, but it is
List *indexorderbys;
bool isjoininner;
ScanDirection indexscandir;
- bool indexonly;
Cost indextotalcost;
Selectivity indexselectivity;
double rows; /* estimated number of result tuples */
* The individual indexscans are represented by IndexPath nodes, and any
* logic on top of them is represented by a tree of BitmapAndPath and
* BitmapOrPath nodes. Notice that we can use the same IndexPath node both
- * to represent a regular IndexScan plan, and as the child of a BitmapHeapPath
- * that represents scanning the same index using a BitmapIndexScan. The
- * startup_cost and total_cost figures of an IndexPath always represent the
- * costs to use it as a regular IndexScan. The costs of a BitmapIndexScan
- * can be computed using the IndexPath's indextotalcost and indexselectivity.
+ * to represent a regular (or index-only) index scan plan, and as the child
+ * of a BitmapHeapPath that represents scanning the same index using a
+ * BitmapIndexScan. The startup_cost and total_cost figures of an IndexPath
+ * always represent the costs to use it as a regular (or index-only)
+ * IndexScan. The costs of a BitmapIndexScan can be computed using the
+ * IndexPath's indextotalcost and indexselectivity.
*
* BitmapHeapPaths can be nestloop inner indexscans. The isjoininner and
* rows fields serve the same purpose as for plain IndexPaths.
projects / postgresql / commitdiff