diff --git a/contrib/postgres_fdw/expected/postgres_fdw.out b/contrib/postgres_fdw/expected/postgres_fdw.out
index 683d641fa7..80239faf21 100644
--- a/contrib/postgres_fdw/expected/postgres_fdw.out
+++ b/contrib/postgres_fdw/expected/postgres_fdw.out
@@ -1979,28 +1979,62 @@ SELECT t1.c1 FROM ft1 t1 WHERE NOT EXISTS (SELECT 1 FROM ft2 t2 WHERE t1.c1 = t2
119
(10 rows)
--- CROSS JOIN, not pushed down
+-- CROSS JOIN, not pushed down. For this query, essential optimization is top-N
+-- sort. But it can't be processed at remote side, because we never do LIMIT
+-- push down. Assuming that sorting is not worth it to push down, CROSS JOIN
+-- is also not pushed down in order to transfer less tuples over network.
EXPLAIN (VERBOSE, COSTS OFF)
-SELECT t1.c1, t2.c1 FROM ft1 t1 CROSS JOIN ft2 t2 ORDER BY t1.c1, t2.c1 OFFSET 100 LIMIT 10;
- QUERY PLAN
----------------------------------------------------------------------
+SELECT t1.c3, t2.c3 FROM ft1 t1 CROSS JOIN ft2 t2 ORDER BY t1.c3, t2.c3 OFFSET 100 LIMIT 10;
+ QUERY PLAN
+------------------------------------------------------------------
Limit
- Output: t1.c1, t2.c1
+ Output: t1.c3, t2.c3
-> Sort
- Output: t1.c1, t2.c1
- Sort Key: t1.c1, t2.c1
+ Output: t1.c3, t2.c3
+ Sort Key: t1.c3, t2.c3
-> Nested Loop
- Output: t1.c1, t2.c1
+ Output: t1.c3, t2.c3
-> Foreign Scan on public.ft1 t1
- Output: t1.c1
- Remote SQL: SELECT "C 1" FROM "S 1"."T 1"
+ Output: t1.c3
+ Remote SQL: SELECT c3 FROM "S 1"."T 1"
-> Materialize
- Output: t2.c1
+ Output: t2.c3
-> Foreign Scan on public.ft2 t2
- Output: t2.c1
- Remote SQL: SELECT "C 1" FROM "S 1"."T 1"
+ Output: t2.c3
+ Remote SQL: SELECT c3 FROM "S 1"."T 1"
(15 rows)
+SELECT t1.c3, t2.c3 FROM ft1 t1 CROSS JOIN ft2 t2 ORDER BY t1.c3, t2.c3 OFFSET 100 LIMIT 10;
+ c3 | c3
+-------+-------
+ 00001 | 00101
+ 00001 | 00102
+ 00001 | 00103
+ 00001 | 00104
+ 00001 | 00105
+ 00001 | 00106
+ 00001 | 00107
+ 00001 | 00108
+ 00001 | 00109
+ 00001 | 00110
+(10 rows)
+
+-- CROSS JOIN, pushed down. Unlike previous query, remote side is able to
+-- return tuples in given order without full sort, but using index scan and
+-- incremental sort. This is much cheaper than full sort on local side, even
+-- despite we don't know LIMIT on remote side.
+EXPLAIN (VERBOSE, COSTS OFF)
+SELECT t1.c1, t2.c1 FROM ft1 t1 CROSS JOIN ft2 t2 ORDER BY t1.c1, t2.c1 OFFSET 100 LIMIT 10;
+ QUERY PLAN
+-------------------------------------------------------------------------------------------------------------------------------------------------------------------
+ Limit
+ Output: t1.c1, t2.c1
+ -> Foreign Scan
+ Output: t1.c1, t2.c1
+ Relations: (public.ft1 t1) INNER JOIN (public.ft2 t2)
+ Remote SQL: SELECT r1."C 1", r2."C 1" FROM ("S 1"."T 1" r1 INNER JOIN "S 1"."T 1" r2 ON (TRUE)) ORDER BY r1."C 1" ASC NULLS LAST, r2."C 1" ASC NULLS LAST
+(6 rows)
+
SELECT t1.c1, t2.c1 FROM ft1 t1 CROSS JOIN ft2 t2 ORDER BY t1.c1, t2.c1 OFFSET 100 LIMIT 10;
c1 | c1
----+-----
diff --git a/contrib/postgres_fdw/sql/postgres_fdw.sql b/contrib/postgres_fdw/sql/postgres_fdw.sql
index 3c3c5c705f..c324394942 100644
--- a/contrib/postgres_fdw/sql/postgres_fdw.sql
+++ b/contrib/postgres_fdw/sql/postgres_fdw.sql
@@ -508,7 +508,17 @@ SELECT t1.c1 FROM ft1 t1 WHERE EXISTS (SELECT 1 FROM ft2 t2 WHERE t1.c1 = t2.c1)
EXPLAIN (VERBOSE, COSTS OFF)
SELECT t1.c1 FROM ft1 t1 WHERE NOT EXISTS (SELECT 1 FROM ft2 t2 WHERE t1.c1 = t2.c2) ORDER BY t1.c1 OFFSET 100 LIMIT 10;
SELECT t1.c1 FROM ft1 t1 WHERE NOT EXISTS (SELECT 1 FROM ft2 t2 WHERE t1.c1 = t2.c2) ORDER BY t1.c1 OFFSET 100 LIMIT 10;
--- CROSS JOIN, not pushed down
+-- CROSS JOIN, not pushed down. For this query, essential optimization is top-N
+-- sort. But it can't be processed at remote side, because we never do LIMIT
+-- push down. Assuming that sorting is not worth it to push down, CROSS JOIN
+-- is also not pushed down in order to transfer less tuples over network.
+EXPLAIN (VERBOSE, COSTS OFF)
+SELECT t1.c3, t2.c3 FROM ft1 t1 CROSS JOIN ft2 t2 ORDER BY t1.c3, t2.c3 OFFSET 100 LIMIT 10;
+SELECT t1.c3, t2.c3 FROM ft1 t1 CROSS JOIN ft2 t2 ORDER BY t1.c3, t2.c3 OFFSET 100 LIMIT 10;
+-- CROSS JOIN, pushed down. Unlike previous query, remote side is able to
+-- return tuples in given order without full sort, but using index scan and
+-- incremental sort. This is much cheaper than full sort on local side, even
+-- despite we don't know LIMIT on remote side.
EXPLAIN (VERBOSE, COSTS OFF)
SELECT t1.c1, t2.c1 FROM ft1 t1 CROSS JOIN ft2 t2 ORDER BY t1.c1, t2.c1 OFFSET 100 LIMIT 10;
SELECT t1.c1, t2.c1 FROM ft1 t1 CROSS JOIN ft2 t2 ORDER BY t1.c1, t2.c1 OFFSET 100 LIMIT 10;
diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index e4a01699e4..fdcdc6683f 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -3553,6 +3553,20 @@ ANY num_sync (
+ enable_incrementalsort (boolean)
+
+ enable_incrementalsort configuration parameter
+
+
+
+
+ Enables or disables the query planner's use of incremental sort
+ steps. The default is on.
+
+
+
+
enable_indexscan (boolean)
diff --git a/src/backend/commands/explain.c b/src/backend/commands/explain.c
index 79e6985d0d..6cf5f8bad1 100644
--- a/src/backend/commands/explain.c
+++ b/src/backend/commands/explain.c
@@ -80,6 +80,8 @@ static void show_upper_qual(List *qual, const char *qlabel,
ExplainState *es);
static void show_sort_keys(SortState *sortstate, List *ancestors,
ExplainState *es);
+static void show_incremental_sort_keys(IncrementalSortState *incrsortstate,
+ List *ancestors, ExplainState *es);
static void show_merge_append_keys(MergeAppendState *mstate, List *ancestors,
ExplainState *es);
static void show_agg_keys(AggState *astate, List *ancestors,
@@ -93,7 +95,7 @@ static void show_grouping_set_keys(PlanState *planstate,
static void show_group_keys(GroupState *gstate, List *ancestors,
ExplainState *es);
static void show_sort_group_keys(PlanState *planstate, const char *qlabel,
- int nkeys, AttrNumber *keycols,
+ int nkeys, int nPresortedKeys, AttrNumber *keycols,
Oid *sortOperators, Oid *collations, bool *nullsFirst,
List *ancestors, ExplainState *es);
static void show_sortorder_options(StringInfo buf, Node *sortexpr,
@@ -101,6 +103,8 @@ static void show_sortorder_options(StringInfo buf, Node *sortexpr,
static void show_tablesample(TableSampleClause *tsc, PlanState *planstate,
List *ancestors, ExplainState *es);
static void show_sort_info(SortState *sortstate, ExplainState *es);
+static void show_incremental_sort_info(IncrementalSortState *incrsortstate,
+ ExplainState *es);
static void show_hash_info(HashState *hashstate, ExplainState *es);
static void show_tidbitmap_info(BitmapHeapScanState *planstate,
ExplainState *es);
@@ -1011,6 +1015,9 @@ ExplainNode(PlanState *planstate, List *ancestors,
case T_Sort:
pname = sname = "Sort";
break;
+ case T_IncrementalSort:
+ pname = sname = "Incremental Sort";
+ break;
case T_Group:
pname = sname = "Group";
break;
@@ -1611,6 +1618,12 @@ ExplainNode(PlanState *planstate, List *ancestors,
show_sort_keys(castNode(SortState, planstate), ancestors, es);
show_sort_info(castNode(SortState, planstate), es);
break;
+ case T_IncrementalSort:
+ show_incremental_sort_keys(castNode(IncrementalSortState, planstate),
+ ancestors, es);
+ show_incremental_sort_info(castNode(IncrementalSortState, planstate),
+ es);
+ break;
case T_MergeAppend:
show_merge_append_keys(castNode(MergeAppendState, planstate),
ancestors, es);
@@ -1936,14 +1949,37 @@ static void
show_sort_keys(SortState *sortstate, List *ancestors, ExplainState *es)
{
Sort *plan = (Sort *) sortstate->ss.ps.plan;
+ int skipCols;
+
+ if (IsA(plan, IncrementalSort))
+ skipCols = ((IncrementalSort *) plan)->skipCols;
+ else
+ skipCols = 0;
show_sort_group_keys((PlanState *) sortstate, "Sort Key",
- plan->numCols, plan->sortColIdx,
+ plan->numCols, skipCols, plan->sortColIdx,
plan->sortOperators, plan->collations,
plan->nullsFirst,
ancestors, es);
}
+/*
+ * Show the sort keys for a IncrementalSort node.
+ */
+static void
+show_incremental_sort_keys(IncrementalSortState *incrsortstate,
+ List *ancestors, ExplainState *es)
+{
+ IncrementalSort *plan = (IncrementalSort *) incrsortstate->ss.ps.plan;
+
+ show_sort_group_keys((PlanState *) incrsortstate, "Sort Key",
+ plan->sort.numCols, plan->skipCols,
+ plan->sort.sortColIdx,
+ plan->sort.sortOperators, plan->sort.collations,
+ plan->sort.nullsFirst,
+ ancestors, es);
+}
+
/*
* Likewise, for a MergeAppend node.
*/
@@ -1954,7 +1990,7 @@ show_merge_append_keys(MergeAppendState *mstate, List *ancestors,
MergeAppend *plan = (MergeAppend *) mstate->ps.plan;
show_sort_group_keys((PlanState *) mstate, "Sort Key",
- plan->numCols, plan->sortColIdx,
+ plan->numCols, 0, plan->sortColIdx,
plan->sortOperators, plan->collations,
plan->nullsFirst,
ancestors, es);
@@ -1978,7 +2014,7 @@ show_agg_keys(AggState *astate, List *ancestors,
show_grouping_sets(outerPlanState(astate), plan, ancestors, es);
else
show_sort_group_keys(outerPlanState(astate), "Group Key",
- plan->numCols, plan->grpColIdx,
+ plan->numCols, 0, plan->grpColIdx,
NULL, NULL, NULL,
ancestors, es);
@@ -2047,7 +2083,7 @@ show_grouping_set_keys(PlanState *planstate,
if (sortnode)
{
show_sort_group_keys(planstate, "Sort Key",
- sortnode->numCols, sortnode->sortColIdx,
+ sortnode->numCols, 0, sortnode->sortColIdx,
sortnode->sortOperators, sortnode->collations,
sortnode->nullsFirst,
ancestors, es);
@@ -2104,7 +2140,7 @@ show_group_keys(GroupState *gstate, List *ancestors,
/* The key columns refer to the tlist of the child plan */
ancestors = lcons(gstate, ancestors);
show_sort_group_keys(outerPlanState(gstate), "Group Key",
- plan->numCols, plan->grpColIdx,
+ plan->numCols, 0, plan->grpColIdx,
NULL, NULL, NULL,
ancestors, es);
ancestors = list_delete_first(ancestors);
@@ -2117,13 +2153,14 @@ show_group_keys(GroupState *gstate, List *ancestors,
*/
static void
show_sort_group_keys(PlanState *planstate, const char *qlabel,
- int nkeys, AttrNumber *keycols,
+ int nkeys, int nPresortedKeys, AttrNumber *keycols,
Oid *sortOperators, Oid *collations, bool *nullsFirst,
List *ancestors, ExplainState *es)
{
Plan *plan = planstate->plan;
List *context;
List *result = NIL;
+ List *resultPresorted = NIL;
StringInfoData sortkeybuf;
bool useprefix;
int keyno;
@@ -2163,9 +2200,13 @@ show_sort_group_keys(PlanState *planstate, const char *qlabel,
nullsFirst[keyno]);
/* Emit one property-list item per sort key */
result = lappend(result, pstrdup(sortkeybuf.data));
+ if (keyno < nPresortedKeys)
+ resultPresorted = lappend(resultPresorted, exprstr);
}
ExplainPropertyList(qlabel, result, es);
+ if (nPresortedKeys > 0)
+ ExplainPropertyList("Presorted Key", resultPresorted, es);
}
/*
@@ -2373,6 +2414,95 @@ show_sort_info(SortState *sortstate, ExplainState *es)
}
}
+/*
+ * If it's EXPLAIN ANALYZE, show tuplesort stats for a incremental sort node
+ */
+static void
+show_incremental_sort_info(IncrementalSortState *incrsortstate,
+ ExplainState *es)
+{
+ if (es->analyze && incrsortstate->sort_Done &&
+ incrsortstate->tuplesortstate != NULL)
+ {
+ Tuplesortstate *state = (Tuplesortstate *) incrsortstate->tuplesortstate;
+ TuplesortInstrumentation stats;
+ const char *sortMethod;
+ const char *spaceType;
+ long spaceUsed;
+
+ tuplesort_get_stats(state, &stats);
+ sortMethod = tuplesort_method_name(stats.sortMethod);
+ spaceType = tuplesort_space_type_name(stats.spaceType);
+ spaceUsed = stats.spaceUsed;
+
+ if (es->format == EXPLAIN_FORMAT_TEXT)
+ {
+ appendStringInfoSpaces(es->str, es->indent * 2);
+ appendStringInfo(es->str, "Sort Method: %s %s: %ldkB\n",
+ sortMethod, spaceType, spaceUsed);
+ appendStringInfoSpaces(es->str, es->indent * 2);
+ appendStringInfo(es->str, "Sort Groups: %ld\n",
+ incrsortstate->groupsCount);
+ }
+ else
+ {
+ ExplainPropertyText("Sort Method", sortMethod, es);
+ ExplainPropertyLong("Sort Space Used", spaceUsed, es);
+ ExplainPropertyText("Sort Space Type", spaceType, es);
+ ExplainPropertyLong("Sort Groups: %ld",
+ incrsortstate->groupsCount, es);
+ }
+ }
+
+ if (incrsortstate->shared_info != NULL)
+ {
+ int n;
+ bool opened_group = false;
+
+ for (n = 0; n < incrsortstate->shared_info->num_workers; n++)
+ {
+ TuplesortInstrumentation *sinstrument;
+ const char *sortMethod;
+ const char *spaceType;
+ long spaceUsed;
+ int64 groupsCount;
+
+ sinstrument = &incrsortstate->shared_info->sinfo[n].sinstrument;
+ groupsCount = incrsortstate->shared_info->sinfo[n].groupsCount;
+ if (sinstrument->sortMethod == SORT_TYPE_STILL_IN_PROGRESS)
+ continue; /* ignore any unfilled slots */
+ sortMethod = tuplesort_method_name(sinstrument->sortMethod);
+ spaceType = tuplesort_space_type_name(sinstrument->spaceType);
+ spaceUsed = sinstrument->spaceUsed;
+
+ if (es->format == EXPLAIN_FORMAT_TEXT)
+ {
+ appendStringInfoSpaces(es->str, es->indent * 2);
+ appendStringInfo(es->str,
+ "Worker %d: Sort Method: %s %s: %ldkB Groups: %ld\n",
+ n, sortMethod, spaceType, spaceUsed, groupsCount);
+ }
+ else
+ {
+ if (!opened_group)
+ {
+ ExplainOpenGroup("Workers", "Workers", false, es);
+ opened_group = true;
+ }
+ ExplainOpenGroup("Worker", NULL, true, es);
+ ExplainPropertyInteger("Worker Number", n, es);
+ ExplainPropertyText("Sort Method", sortMethod, es);
+ ExplainPropertyLong("Sort Space Used", spaceUsed, es);
+ ExplainPropertyText("Sort Space Type", spaceType, es);
+ ExplainPropertyLong("Sort Groups", groupsCount, es);
+ ExplainCloseGroup("Worker", NULL, true, es);
+ }
+ }
+ if (opened_group)
+ ExplainCloseGroup("Workers", "Workers", false, es);
+ }
+}
+
/*
* Show information on hash buckets/batches.
*/
diff --git a/src/backend/executor/Makefile b/src/backend/executor/Makefile
index cc09895fa5..572aca05fb 100644
--- a/src/backend/executor/Makefile
+++ b/src/backend/executor/Makefile
@@ -24,8 +24,8 @@ OBJS = execAmi.o execCurrent.o execExpr.o execExprInterp.o \
nodeLimit.o nodeLockRows.o nodeGatherMerge.o \
nodeMaterial.o nodeMergeAppend.o nodeMergejoin.o nodeModifyTable.o \
nodeNestloop.o nodeProjectSet.o nodeRecursiveunion.o nodeResult.o \
- nodeSamplescan.o nodeSeqscan.o nodeSetOp.o nodeSort.o nodeUnique.o \
- nodeValuesscan.o \
+ nodeSamplescan.o nodeSeqscan.o nodeSetOp.o \
+ nodeSort.o nodeIncrementalSort.o nodeUnique.o nodeValuesscan.o \
nodeCtescan.o nodeNamedtuplestorescan.o nodeWorktablescan.o \
nodeGroup.o nodeSubplan.o nodeSubqueryscan.o nodeTidscan.o \
nodeForeignscan.o nodeWindowAgg.o tstoreReceiver.o tqueue.o spi.o \
diff --git a/src/backend/executor/execAmi.c b/src/backend/executor/execAmi.c
index 9e78421978..34e05330ea 100644
--- a/src/backend/executor/execAmi.c
+++ b/src/backend/executor/execAmi.c
@@ -31,6 +31,7 @@
#include "executor/nodeGroup.h"
#include "executor/nodeHash.h"
#include "executor/nodeHashjoin.h"
+#include "executor/nodeIncrementalSort.h"
#include "executor/nodeIndexonlyscan.h"
#include "executor/nodeIndexscan.h"
#include "executor/nodeLimit.h"
@@ -253,6 +254,10 @@ ExecReScan(PlanState *node)
ExecReScanSort((SortState *) node);
break;
+ case T_IncrementalSortState:
+ ExecReScanIncrementalSort((IncrementalSortState *) node);
+ break;
+
case T_GroupState:
ExecReScanGroup((GroupState *) node);
break;
@@ -525,8 +530,12 @@ ExecSupportsBackwardScan(Plan *node)
case T_CteScan:
case T_Material:
case T_Sort:
+ /* these don't evaluate tlist */
return true;
+ case T_IncrementalSort:
+ return false;
+
case T_LockRows:
case T_Limit:
return ExecSupportsBackwardScan(outerPlan(node));
diff --git a/src/backend/executor/execParallel.c b/src/backend/executor/execParallel.c
index f8b72ebab9..490d6dd76c 100644
--- a/src/backend/executor/execParallel.c
+++ b/src/backend/executor/execParallel.c
@@ -32,6 +32,7 @@
#include "executor/nodeForeignscan.h"
#include "executor/nodeHash.h"
#include "executor/nodeHashjoin.h"
+#include "executor/nodeIncrementalSort.h"
#include "executor/nodeIndexscan.h"
#include "executor/nodeIndexonlyscan.h"
#include "executor/nodeSeqscan.h"
@@ -280,6 +281,10 @@ ExecParallelEstimate(PlanState *planstate, ExecParallelEstimateContext *e)
/* even when not parallel-aware, for EXPLAIN ANALYZE */
ExecSortEstimate((SortState *) planstate, e->pcxt);
break;
+ case T_IncrementalSortState:
+ /* even when not parallel-aware */
+ ExecIncrementalSortEstimate((IncrementalSortState *) planstate, e->pcxt);
+ break;
default:
break;
@@ -493,6 +498,10 @@ ExecParallelInitializeDSM(PlanState *planstate,
/* even when not parallel-aware, for EXPLAIN ANALYZE */
ExecSortInitializeDSM((SortState *) planstate, d->pcxt);
break;
+ case T_IncrementalSortState:
+ /* even when not parallel-aware */
+ ExecIncrementalSortInitializeDSM((IncrementalSortState *) planstate, d->pcxt);
+ break;
default:
break;
@@ -918,6 +927,10 @@ ExecParallelReInitializeDSM(PlanState *planstate,
case T_SortState:
/* these nodes have DSM state, but no reinitialization is required */
break;
+ case T_IncrementalSortState:
+ /* even when not parallel-aware */
+ ExecIncrementalSortReInitializeDSM((IncrementalSortState *) planstate, pcxt);
+ break;
default:
break;
@@ -976,6 +989,9 @@ ExecParallelRetrieveInstrumentation(PlanState *planstate,
case T_SortState:
ExecSortRetrieveInstrumentation((SortState *) planstate);
break;
+ case T_IncrementalSortState:
+ ExecIncrementalSortRetrieveInstrumentation((IncrementalSortState *) planstate);
+ break;
case T_HashState:
ExecHashRetrieveInstrumentation((HashState *) planstate);
break;
@@ -1225,6 +1241,11 @@ ExecParallelInitializeWorker(PlanState *planstate, ParallelWorkerContext *pwcxt)
/* even when not parallel-aware, for EXPLAIN ANALYZE */
ExecSortInitializeWorker((SortState *) planstate, pwcxt);
break;
+ case T_IncrementalSortState:
+ /* even when not parallel-aware */
+ ExecIncrementalSortInitializeWorker((IncrementalSortState *) planstate,
+ pwcxt);
+ break;
default:
break;
diff --git a/src/backend/executor/execProcnode.c b/src/backend/executor/execProcnode.c
index 43a27a9af2..17163448a3 100644
--- a/src/backend/executor/execProcnode.c
+++ b/src/backend/executor/execProcnode.c
@@ -88,6 +88,7 @@
#include "executor/nodeGroup.h"
#include "executor/nodeHash.h"
#include "executor/nodeHashjoin.h"
+#include "executor/nodeIncrementalSort.h"
#include "executor/nodeIndexonlyscan.h"
#include "executor/nodeIndexscan.h"
#include "executor/nodeLimit.h"
@@ -314,6 +315,11 @@ ExecInitNode(Plan *node, EState *estate, int eflags)
estate, eflags);
break;
+ case T_IncrementalSort:
+ result = (PlanState *) ExecInitIncrementalSort((IncrementalSort *) node,
+ estate, eflags);
+ break;
+
case T_Group:
result = (PlanState *) ExecInitGroup((Group *) node,
estate, eflags);
@@ -695,6 +701,10 @@ ExecEndNode(PlanState *node)
ExecEndSort((SortState *) node);
break;
+ case T_IncrementalSortState:
+ ExecEndIncrementalSort((IncrementalSortState *) node);
+ break;
+
case T_GroupState:
ExecEndGroup((GroupState *) node);
break;
diff --git a/src/backend/executor/nodeAgg.c b/src/backend/executor/nodeAgg.c
index 46ee880415..30855c3fe7 100644
--- a/src/backend/executor/nodeAgg.c
+++ b/src/backend/executor/nodeAgg.c
@@ -667,6 +667,7 @@ initialize_phase(AggState *aggstate, int newphase)
sortnode->collations,
sortnode->nullsFirst,
work_mem,
+ false,
false);
}
@@ -754,7 +755,7 @@ initialize_aggregate(AggState *aggstate, AggStatePerTrans pertrans,
pertrans->sortOperators,
pertrans->sortCollations,
pertrans->sortNullsFirst,
- work_mem, false);
+ work_mem, false, false);
}
/*
diff --git a/src/backend/executor/nodeIncrementalSort.c b/src/backend/executor/nodeIncrementalSort.c
new file mode 100644
index 0000000000..a8e55e5e2d
--- /dev/null
+++ b/src/backend/executor/nodeIncrementalSort.c
@@ -0,0 +1,646 @@
+/*-------------------------------------------------------------------------
+ *
+ * nodeIncremenalSort.c
+ * Routines to handle incremental sorting of relations.
+ *
+ * DESCRIPTION
+ *
+ * Incremental sort is a specially optimized kind of multikey sort used
+ * when the input is already presorted by a prefix of the required keys
+ * list. Thus, when it's required to sort by (key1, key2 ... keyN) and
+ * result is already sorted by (key1, key2 ... keyM), M < N, we sort groups
+ * where values of (key1, key2 ... keyM) are equal.
+ *
+ * Consider the following example. We have input tuples consisting from
+ * two integers (x, y) already presorted by x, while it's required to
+ * sort them by x and y. Let input tuples be following.
+ *
+ * (1, 5)
+ * (1, 2)
+ * (2, 10)
+ * (2, 1)
+ * (2, 5)
+ * (3, 3)
+ * (3, 7)
+ *
+ * Incremental sort algorithm would sort by y following groups, which have
+ * equal x, individually:
+ * (1, 5) (1, 2)
+ * (2, 10) (2, 1) (2, 5)
+ * (3, 3) (3, 7)
+ *
+ * After sorting these groups and putting them altogether, we would get
+ * following tuple set which is actually sorted by x and y.
+ *
+ * (1, 2)
+ * (1, 5)
+ * (2, 1)
+ * (2, 5)
+ * (2, 10)
+ * (3, 3)
+ * (3, 7)
+ *
+ * Incremental sort is faster than full sort on large datasets. But
+ * the case of most huge benefit of incremental sort is queries with
+ * LIMIT because incremental sort can return first tuples without reading
+ * whole input dataset.
+ *
+ * Portions Copyright (c) 1996-2018, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ * src/backend/executor/nodeIncremenalSort.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "postgres.h"
+
+#include "access/htup_details.h"
+#include "executor/execdebug.h"
+#include "executor/nodeIncrementalSort.h"
+#include "miscadmin.h"
+#include "utils/lsyscache.h"
+#include "utils/tuplesort.h"
+
+/*
+ * Prepare information for skipKeys comparison.
+ */
+static void
+prepareSkipCols(IncrementalSortState *node)
+{
+ IncrementalSort *plannode = (IncrementalSort *) node->ss.ps.plan;
+ int skipCols,
+ i;
+
+ Assert(IsA(plannode, IncrementalSort));
+ skipCols = plannode->skipCols;
+
+ node->skipKeys = (SkipKeyData *) palloc(skipCols * sizeof(SkipKeyData));
+
+ for (i = 0; i < skipCols; i++)
+ {
+ Oid equalityOp, equalityFunc;
+ SkipKeyData *key;
+
+ key = &node->skipKeys[i];
+ key->attno = plannode->sort.sortColIdx[i];
+
+ equalityOp = get_equality_op_for_ordering_op(
+ plannode->sort.sortOperators[i], NULL);
+ if (!OidIsValid(equalityOp))
+ elog(ERROR, "missing equality operator for ordering operator %u",
+ plannode->sort.sortOperators[i]);
+
+ equalityFunc = get_opcode(equalityOp);
+ if (!OidIsValid(equalityFunc))
+ elog(ERROR, "missing function for operator %u", equalityOp);
+
+ /* Lookup the comparison function */
+ fmgr_info_cxt(equalityFunc, &key->flinfo, CurrentMemoryContext);
+
+ /* We can initialize the callinfo just once and re-use it */
+ InitFunctionCallInfoData(key->fcinfo, &key->flinfo, 2,
+ plannode->sort.collations[i], NULL, NULL);
+ key->fcinfo.argnull[0] = false;
+ key->fcinfo.argnull[1] = false;
+ }
+}
+
+/*
+ * Check if first "skipCols" sort values are equal.
+ */
+static bool
+cmpSortSkipCols(IncrementalSortState *node, TupleTableSlot *a,
+ TupleTableSlot *b)
+{
+ int n, i;
+
+ Assert(IsA(node->ss.ps.plan, IncrementalSort));
+
+ n = ((IncrementalSort *) node->ss.ps.plan)->skipCols;
+
+ for (i = 0; i < n; i++)
+ {
+ Datum datumA, datumB, result;
+ bool isnullA, isnullB;
+ AttrNumber attno = node->skipKeys[i].attno;
+ SkipKeyData *key;
+
+ datumA = slot_getattr(a, attno, &isnullA);
+ datumB = slot_getattr(b, attno, &isnullB);
+
+ /* Special case for NULL-vs-NULL, else use standard comparison */
+ if (isnullA || isnullB)
+ {
+ if (isnullA == isnullB)
+ continue;
+ else
+ return false;
+ }
+
+ key = &node->skipKeys[i];
+
+ key->fcinfo.arg[0] = datumA;
+ key->fcinfo.arg[1] = datumB;
+
+ /* just for paranoia's sake, we reset isnull each time */
+ key->fcinfo.isnull = false;
+
+ result = FunctionCallInvoke(&key->fcinfo);
+
+ /* Check for null result, since caller is clearly not expecting one */
+ if (key->fcinfo.isnull)
+ elog(ERROR, "function %u returned NULL", key->flinfo.fn_oid);
+
+ if (!DatumGetBool(result))
+ return false;
+ }
+ return true;
+}
+
+/*
+ * Copying of tuples to the node->sampleSlot introduces some overhead. It's
+ * especially notable when groups are containing one or few tuples. In order
+ * to cope this problem we don't copy sample tuple before the group contains
+ * at least MIN_GROUP_SIZE of tuples. Surely, it might reduce efficiency of
+ * incremental sort, but it reduces the probability of regression.
+ */
+#define MIN_GROUP_SIZE 32
+
+/* ----------------------------------------------------------------
+ * ExecIncrementalSort
+ *
+ * Assuming that outer subtree returns tuple presorted by some prefix
+ * of target sort columns, performs incremental sort. It fetches
+ * groups of tuples where prefix sort columns are equal and sorts them
+ * using tuplesort. This approach allows to evade sorting of whole
+ * dataset. Besides taking less memory and being faster, it allows to
+ * start returning tuples before fetching full dataset from outer
+ * subtree.
+ *
+ * Conditions:
+ * -- none.
+ *
+ * Initial States:
+ * -- the outer child is prepared to return the first tuple.
+ * ----------------------------------------------------------------
+ */
+static TupleTableSlot *
+ExecIncrementalSort(PlanState *pstate)
+{
+ IncrementalSortState *node = castNode(IncrementalSortState, pstate);
+ EState *estate;
+ ScanDirection dir;
+ Tuplesortstate *tuplesortstate;
+ TupleTableSlot *slot;
+ IncrementalSort *plannode = (IncrementalSort *) node->ss.ps.plan;
+ PlanState *outerNode;
+ TupleDesc tupDesc;
+ int64 nTuples = 0;
+
+ /*
+ * get state info from node
+ */
+ SO1_printf("ExecIncrementalSort: %s\n",
+ "entering routine");
+
+ estate = node->ss.ps.state;
+ dir = estate->es_direction;
+ tuplesortstate = (Tuplesortstate *) node->tuplesortstate;
+
+ /*
+ * Return next tuple from sorted set if any.
+ */
+ if (node->sort_Done)
+ {
+ slot = node->ss.ps.ps_ResultTupleSlot;
+ if (tuplesort_gettupleslot(tuplesortstate,
+ ScanDirectionIsForward(dir),
+ false, slot, NULL) || node->finished)
+ return slot;
+ }
+
+ /*
+ * If first time through, read all tuples from outer plan and pass them to
+ * tuplesort.c. Subsequent calls just fetch tuples from tuplesort.
+ */
+
+ SO1_printf("ExecIncrementalSort: %s\n",
+ "sorting subplan");
+
+ /*
+ * Want to scan subplan in the forward direction while creating the
+ * sorted data.
+ */
+ estate->es_direction = ForwardScanDirection;
+
+ /*
+ * Initialize tuplesort module.
+ */
+ SO1_printf("ExecIncrementalSort: %s\n",
+ "calling tuplesort_begin");
+
+ outerNode = outerPlanState(node);
+ tupDesc = ExecGetResultType(outerNode);
+
+ if (node->tuplesortstate == NULL)
+ {
+ /*
+ * We are going to process the first group of presorted data.
+ * Initialize support structures for cmpSortSkipCols - already
+ * sorted columns.
+ */
+ prepareSkipCols(node);
+
+ /*
+ * Pass all the columns to tuplesort. We pass to tuple sort groups
+ * of at least MIN_GROUP_SIZE size. Thus, these groups doesn't
+ * necessary have equal value of the first column. We unlikely will
+ * have huge groups with incremental sort. Therefore usage of
+ * abbreviated keys would be likely a waste of time.
+ */
+ tuplesortstate = tuplesort_begin_heap(
+ tupDesc,
+ plannode->sort.numCols,
+ plannode->sort.sortColIdx,
+ plannode->sort.sortOperators,
+ plannode->sort.collations,
+ plannode->sort.nullsFirst,
+ work_mem,
+ false,
+ true);
+ node->tuplesortstate = (void *) tuplesortstate;
+ }
+ else
+ {
+ /* Next group of presorted data */
+ tuplesort_reset((Tuplesortstate *) node->tuplesortstate);
+ }
+ node->groupsCount++;
+
+ /* Calculate remaining bound for bounded sort */
+ if (node->bounded)
+ tuplesort_set_bound(tuplesortstate, node->bound - node->bound_Done);
+
+ /* Put saved tuple to tuplesort if any */
+ if (!TupIsNull(node->sampleSlot))
+ {
+ tuplesort_puttupleslot(tuplesortstate, node->sampleSlot);
+ ExecClearTuple(node->sampleSlot);
+ nTuples++;
+ }
+
+ /*
+ * Put next group of tuples where skipCols sort values are equal to
+ * tuplesort.
+ */
+ for (;;)
+ {
+ slot = ExecProcNode(outerNode);
+
+ if (TupIsNull(slot))
+ {
+ node->finished = true;
+ break;
+ }
+
+ /* Put next group of presorted data to the tuplesort */
+ if (nTuples < MIN_GROUP_SIZE)
+ {
+ tuplesort_puttupleslot(tuplesortstate, slot);
+
+ /* Save last tuple in minimal group */
+ if (nTuples == MIN_GROUP_SIZE - 1)
+ ExecCopySlot(node->sampleSlot, slot);
+ nTuples++;
+ }
+ else
+ {
+ /* Iterate while skip cols are the same as in saved tuple */
+ if (cmpSortSkipCols(node, node->sampleSlot, slot))
+ {
+ tuplesort_puttupleslot(tuplesortstate, slot);
+ nTuples++;
+ }
+ else
+ {
+ ExecCopySlot(node->sampleSlot, slot);
+ break;
+ }
+ }
+ }
+
+ /*
+ * Complete the sort.
+ */
+ tuplesort_performsort(tuplesortstate);
+
+ /*
+ * restore to user specified direction
+ */
+ estate->es_direction = dir;
+
+ /*
+ * finally set the sorted flag to true
+ */
+ node->sort_Done = true;
+ node->bounded_Done = node->bounded;
+ if (node->shared_info && node->am_worker)
+ {
+ TuplesortInstrumentation *si;
+
+ Assert(IsParallelWorker());
+ Assert(ParallelWorkerNumber <= node->shared_info->num_workers);
+ si = &node->shared_info->sinfo[ParallelWorkerNumber].sinstrument;
+ tuplesort_get_stats(tuplesortstate, si);
+ node->shared_info->sinfo[ParallelWorkerNumber].groupsCount =
+ node->groupsCount;
+ }
+
+ /*
+ * Adjust bound_Done with number of tuples we've actually sorted.
+ */
+ if (node->bounded)
+ {
+ if (node->finished)
+ node->bound_Done = node->bound;
+ else
+ node->bound_Done = Min(node->bound, node->bound_Done + nTuples);
+ }
+
+ SO1_printf("ExecIncrementalSort: %s\n", "sorting done");
+
+ SO1_printf("ExecIncrementalSort: %s\n",
+ "retrieving tuple from tuplesort");
+
+ /*
+ * Get the first or next tuple from tuplesort. Returns NULL if no more
+ * tuples.
+ */
+ slot = node->ss.ps.ps_ResultTupleSlot;
+ (void) tuplesort_gettupleslot(tuplesortstate,
+ ScanDirectionIsForward(dir),
+ false, slot, NULL);
+ return slot;
+}
+
+/* ----------------------------------------------------------------
+ * ExecInitIncrementalSort
+ *
+ * Creates the run-time state information for the sort node
+ * produced by the planner and initializes its outer subtree.
+ * ----------------------------------------------------------------
+ */
+IncrementalSortState *
+ExecInitIncrementalSort(IncrementalSort *node, EState *estate, int eflags)
+{
+ IncrementalSortState *incrsortstate;
+
+ SO1_printf("ExecInitIncrementalSort: %s\n",
+ "initializing sort node");
+
+ /*
+ * Incremental sort can't be used with either EXEC_FLAG_REWIND,
+ * EXEC_FLAG_BACKWARD or EXEC_FLAG_MARK, because we hold only current
+ * bucket in tuplesortstate.
+ */
+ Assert((eflags & (EXEC_FLAG_REWIND |
+ EXEC_FLAG_BACKWARD |
+ EXEC_FLAG_MARK)) == 0);
+
+ /*
+ * create state structure
+ */
+ incrsortstate = makeNode(IncrementalSortState);
+ incrsortstate->ss.ps.plan = (Plan *) node;
+ incrsortstate->ss.ps.state = estate;
+ incrsortstate->ss.ps.ExecProcNode = ExecIncrementalSort;
+
+ incrsortstate->bounded = false;
+ incrsortstate->sort_Done = false;
+ incrsortstate->finished = false;
+ incrsortstate->tuplesortstate = NULL;
+ incrsortstate->sampleSlot = NULL;
+ incrsortstate->bound_Done = 0;
+ incrsortstate->groupsCount = 0;
+ incrsortstate->skipKeys = NULL;
+
+ /*
+ * Miscellaneous initialization
+ *
+ * Sort nodes don't initialize their ExprContexts because they never call
+ * ExecQual or ExecProject.
+ */
+
+ /*
+ * tuple table initialization
+ *
+ * sort nodes only return scan tuples from their sorted relation.
+ */
+ ExecInitResultTupleSlot(estate, &incrsortstate->ss.ps);
+ ExecInitScanTupleSlot(estate, &incrsortstate->ss);
+
+ /*
+ * initialize child nodes
+ *
+ * We shield the child node from the need to support REWIND, BACKWARD, or
+ * MARK/RESTORE.
+ */
+ eflags &= ~(EXEC_FLAG_REWIND | EXEC_FLAG_BACKWARD | EXEC_FLAG_MARK);
+
+ outerPlanState(incrsortstate) = ExecInitNode(outerPlan(node), estate, eflags);
+
+ /*
+ * initialize tuple type. no need to initialize projection info because
+ * this node doesn't do projections.
+ */
+ ExecAssignResultTypeFromTL(&incrsortstate->ss.ps);
+ ExecAssignScanTypeFromOuterPlan(&incrsortstate->ss);
+ incrsortstate->ss.ps.ps_ProjInfo = NULL;
+
+ /* make standalone slot to store previous tuple from outer node */
+ incrsortstate->sampleSlot = MakeSingleTupleTableSlot(
+ ExecGetResultType(outerPlanState(incrsortstate)));
+
+ SO1_printf("ExecInitIncrementalSort: %s\n",
+ "sort node initialized");
+
+ return incrsortstate;
+}
+
+/* ----------------------------------------------------------------
+ * ExecEndIncrementalSort(node)
+ * ----------------------------------------------------------------
+ */
+void
+ExecEndIncrementalSort(IncrementalSortState *node)
+{
+ SO1_printf("ExecEndIncrementalSort: %s\n",
+ "shutting down sort node");
+
+ /*
+ * clean out the tuple table
+ */
+ ExecClearTuple(node->ss.ss_ScanTupleSlot);
+ /* must drop pointer to sort result tuple */
+ ExecClearTuple(node->ss.ps.ps_ResultTupleSlot);
+ /* must drop stanalone tuple slot from outer node */
+ ExecDropSingleTupleTableSlot(node->sampleSlot);
+
+ /*
+ * Release tuplesort resources
+ */
+ if (node->tuplesortstate != NULL)
+ tuplesort_end((Tuplesortstate *) node->tuplesortstate);
+ node->tuplesortstate = NULL;
+
+ /*
+ * shut down the subplan
+ */
+ ExecEndNode(outerPlanState(node));
+
+ SO1_printf("ExecEndIncrementalSort: %s\n",
+ "sort node shutdown");
+}
+
+void
+ExecReScanIncrementalSort(IncrementalSortState *node)
+{
+ PlanState *outerPlan = outerPlanState(node);
+
+ /*
+ * If we haven't sorted yet, just return. If outerplan's chgParam is not
+ * NULL then it will be re-scanned by ExecProcNode, else no reason to
+ * re-scan it at all.
+ */
+ if (!node->sort_Done)
+ return;
+
+ /* must drop pointer to sort result tuple */
+ ExecClearTuple(node->ss.ps.ps_ResultTupleSlot);
+
+ /*
+ * If subnode is to be rescanned then we forget previous sort results; we
+ * have to re-read the subplan and re-sort. Also must re-sort if the
+ * bounded-sort parameters changed or we didn't select randomAccess.
+ *
+ * Otherwise we can just rewind and rescan the sorted output.
+ */
+ node->sort_Done = false;
+ tuplesort_end((Tuplesortstate *) node->tuplesortstate);
+ node->tuplesortstate = NULL;
+ node->bound_Done = 0;
+
+ /*
+ * if chgParam of subnode is not null then plan will be re-scanned by
+ * first ExecProcNode.
+ */
+ if (outerPlan->chgParam == NULL)
+ ExecReScan(outerPlan);
+}
+
+/* ----------------------------------------------------------------
+ * Parallel Query Support
+ * ----------------------------------------------------------------
+ */
+
+/* ----------------------------------------------------------------
+ * ExecSortEstimate
+ *
+ * Estimate space required to propagate sort statistics.
+ * ----------------------------------------------------------------
+ */
+void
+ExecIncrementalSortEstimate(IncrementalSortState *node, ParallelContext *pcxt)
+{
+ Size size;
+
+ /* don't need this if not instrumenting or no workers */
+ if (!node->ss.ps.instrument || pcxt->nworkers == 0)
+ return;
+
+ size = mul_size(pcxt->nworkers, sizeof(IncrementalSortInfo));
+ size = add_size(size, offsetof(SharedIncrementalSortInfo, sinfo));
+ shm_toc_estimate_chunk(&pcxt->estimator, size);
+ shm_toc_estimate_keys(&pcxt->estimator, 1);
+}
+
+/* ----------------------------------------------------------------
+ * ExecSortInitializeDSM
+ *
+ * Initialize DSM space for sort statistics.
+ * ----------------------------------------------------------------
+ */
+void
+ExecIncrementalSortInitializeDSM(IncrementalSortState *node, ParallelContext *pcxt)
+{
+ Size size;
+
+ /* don't need this if not instrumenting or no workers */
+ if (!node->ss.ps.instrument || pcxt->nworkers == 0)
+ return;
+
+ size = offsetof(SharedIncrementalSortInfo, sinfo)
+ + pcxt->nworkers * sizeof(IncrementalSortInfo);
+ node->shared_info = shm_toc_allocate(pcxt->toc, size);
+ /* ensure any unfilled slots will contain zeroes */
+ memset(node->shared_info, 0, size);
+ node->shared_info->num_workers = pcxt->nworkers;
+ shm_toc_insert(pcxt->toc, node->ss.ps.plan->plan_node_id,
+ node->shared_info);
+}
+
+/* ----------------------------------------------------------------
+ * ExecSortReInitializeDSM
+ *
+ * Reset shared state before beginning a fresh scan.
+ * ----------------------------------------------------------------
+ */
+void
+ExecIncrementalSortReInitializeDSM(IncrementalSortState *node, ParallelContext *pcxt)
+{
+ /* If there's any instrumentation space, clear it for next time */
+ if (node->shared_info != NULL)
+ {
+ memset(node->shared_info->sinfo, 0,
+ node->shared_info->num_workers * sizeof(IncrementalSortInfo));
+ }
+}
+
+/* ----------------------------------------------------------------
+ * ExecSortInitializeWorker
+ *
+ * Attach worker to DSM space for sort statistics.
+ * ----------------------------------------------------------------
+ */
+void
+ExecIncrementalSortInitializeWorker(IncrementalSortState *node, ParallelWorkerContext *pwcxt)
+{
+ node->shared_info =
+ shm_toc_lookup(pwcxt->toc, node->ss.ps.plan->plan_node_id, true);
+ node->am_worker = true;
+}
+
+/* ----------------------------------------------------------------
+ * ExecSortRetrieveInstrumentation
+ *
+ * Transfer sort statistics from DSM to private memory.
+ * ----------------------------------------------------------------
+ */
+void
+ExecIncrementalSortRetrieveInstrumentation(IncrementalSortState *node)
+{
+ Size size;
+ SharedIncrementalSortInfo *si;
+
+ if (node->shared_info == NULL)
+ return;
+
+ size = offsetof(SharedIncrementalSortInfo, sinfo)
+ + node->shared_info->num_workers * sizeof(IncrementalSortInfo);
+ si = palloc(size);
+ memcpy(si, node->shared_info, size);
+ node->shared_info = si;
+}
diff --git a/src/backend/executor/nodeSort.c b/src/backend/executor/nodeSort.c
index 9c68de8565..90c82af17f 100644
--- a/src/backend/executor/nodeSort.c
+++ b/src/backend/executor/nodeSort.c
@@ -93,7 +93,8 @@ ExecSort(PlanState *pstate)
plannode->collations,
plannode->nullsFirst,
work_mem,
- node->randomAccess);
+ node->randomAccess,
+ false);
if (node->bounded)
tuplesort_set_bound(tuplesortstate, node->bound);
node->tuplesortstate = (void *) tuplesortstate;
diff --git a/src/backend/nodes/copyfuncs.c b/src/backend/nodes/copyfuncs.c
index ddbbc79823..94d5ba0e41 100644
--- a/src/backend/nodes/copyfuncs.c
+++ b/src/backend/nodes/copyfuncs.c
@@ -919,6 +919,24 @@ _copyMaterial(const Material *from)
}
+/*
+ * CopySortFields
+ *
+ * This function copies the fields of the Sort node. It is used by
+ * all the copy functions for classes which inherit from Sort.
+ */
+static void
+CopySortFields(const Sort *from, Sort *newnode)
+{
+ CopyPlanFields((const Plan *) from, (Plan *) newnode);
+
+ COPY_SCALAR_FIELD(numCols);
+ COPY_POINTER_FIELD(sortColIdx, from->numCols * sizeof(AttrNumber));
+ COPY_POINTER_FIELD(sortOperators, from->numCols * sizeof(Oid));
+ COPY_POINTER_FIELD(collations, from->numCols * sizeof(Oid));
+ COPY_POINTER_FIELD(nullsFirst, from->numCols * sizeof(bool));
+}
+
/*
* _copySort
*/
@@ -930,13 +948,29 @@ _copySort(const Sort *from)
/*
* copy node superclass fields
*/
- CopyPlanFields((const Plan *) from, (Plan *) newnode);
+ CopySortFields(from, newnode);
- COPY_SCALAR_FIELD(numCols);
- COPY_POINTER_FIELD(sortColIdx, from->numCols * sizeof(AttrNumber));
- COPY_POINTER_FIELD(sortOperators, from->numCols * sizeof(Oid));
- COPY_POINTER_FIELD(collations, from->numCols * sizeof(Oid));
- COPY_POINTER_FIELD(nullsFirst, from->numCols * sizeof(bool));
+ return newnode;
+}
+
+
+/*
+ * _copyIncrementalSort
+ */
+static IncrementalSort *
+_copyIncrementalSort(const IncrementalSort *from)
+{
+ IncrementalSort *newnode = makeNode(IncrementalSort);
+
+ /*
+ * copy node superclass fields
+ */
+ CopySortFields((const Sort *) from, (Sort *) newnode);
+
+ /*
+ * copy remainder of node
+ */
+ COPY_SCALAR_FIELD(skipCols);
return newnode;
}
@@ -4817,6 +4851,9 @@ copyObjectImpl(const void *from)
case T_Sort:
retval = _copySort(from);
break;
+ case T_IncrementalSort:
+ retval = _copyIncrementalSort(from);
+ break;
case T_Group:
retval = _copyGroup(from);
break;
diff --git a/src/backend/nodes/outfuncs.c b/src/backend/nodes/outfuncs.c
index 5e72df137e..415a9e9b19 100644
--- a/src/backend/nodes/outfuncs.c
+++ b/src/backend/nodes/outfuncs.c
@@ -870,12 +870,10 @@ _outMaterial(StringInfo str, const Material *node)
}
static void
-_outSort(StringInfo str, const Sort *node)
+_outSortInfo(StringInfo str, const Sort *node)
{
int i;
- WRITE_NODE_TYPE("SORT");
-
_outPlanInfo(str, (const Plan *) node);
WRITE_INT_FIELD(numCols);
@@ -897,6 +895,24 @@ _outSort(StringInfo str, const Sort *node)
appendStringInfo(str, " %s", booltostr(node->nullsFirst[i]));
}
+static void
+_outSort(StringInfo str, const Sort *node)
+{
+ WRITE_NODE_TYPE("SORT");
+
+ _outSortInfo(str, node);
+}
+
+static void
+_outIncrementalSort(StringInfo str, const IncrementalSort *node)
+{
+ WRITE_NODE_TYPE("INCREMENTALSORT");
+
+ _outSortInfo(str, (const Sort *) node);
+
+ WRITE_INT_FIELD(skipCols);
+}
+
static void
_outUnique(StringInfo str, const Unique *node)
{
@@ -3739,6 +3755,9 @@ outNode(StringInfo str, const void *obj)
case T_Sort:
_outSort(str, obj);
break;
+ case T_IncrementalSort:
+ _outIncrementalSort(str, obj);
+ break;
case T_Unique:
_outUnique(str, obj);
break;
diff --git a/src/backend/nodes/readfuncs.c b/src/backend/nodes/readfuncs.c
index 9925866b53..9f64d50103 100644
--- a/src/backend/nodes/readfuncs.c
+++ b/src/backend/nodes/readfuncs.c
@@ -2060,12 +2060,13 @@ _readMaterial(void)
}
/*
- * _readSort
+ * ReadCommonSort
+ * Assign the basic stuff of all nodes that inherit from Sort
*/
-static Sort *
-_readSort(void)
+static void
+ReadCommonSort(Sort *local_node)
{
- READ_LOCALS(Sort);
+ READ_TEMP_LOCALS();
ReadCommonPlan(&local_node->plan);
@@ -2074,6 +2075,32 @@ _readSort(void)
READ_OID_ARRAY(sortOperators, local_node->numCols);
READ_OID_ARRAY(collations, local_node->numCols);
READ_BOOL_ARRAY(nullsFirst, local_node->numCols);
+}
+
+/*
+ * _readSort
+ */
+static Sort *
+_readSort(void)
+{
+ READ_LOCALS_NO_FIELDS(Sort);
+
+ ReadCommonSort(local_node);
+
+ READ_DONE();
+}
+
+/*
+ * _readIncrementalSort
+ */
+static IncrementalSort *
+_readIncrementalSort(void)
+{
+ READ_LOCALS(IncrementalSort);
+
+ ReadCommonSort(&local_node->sort);
+
+ READ_INT_FIELD(skipCols);
READ_DONE();
}
@@ -2636,6 +2663,8 @@ parseNodeString(void)
return_value = _readMaterial();
else if (MATCH("SORT", 4))
return_value = _readSort();
+ else if (MATCH("INCREMENTALSORT", 15))
+ return_value = _readIncrementalSort();
else if (MATCH("GROUP", 5))
return_value = _readGroup();
else if (MATCH("AGG", 3))
diff --git a/src/backend/optimizer/path/allpaths.c b/src/backend/optimizer/path/allpaths.c
index 12a6ee4a22..e96c5fe137 100644
--- a/src/backend/optimizer/path/allpaths.c
+++ b/src/backend/optimizer/path/allpaths.c
@@ -3613,6 +3613,10 @@ print_path(PlannerInfo *root, Path *path, int indent)
ptype = "Sort";
subpath = ((SortPath *) path)->subpath;
break;
+ case T_IncrementalSortPath:
+ ptype = "IncrementalSort";
+ subpath = ((SortPath *) path)->subpath;
+ break;
case T_GroupPath:
ptype = "Group";
subpath = ((GroupPath *) path)->subpath;
diff --git a/src/backend/optimizer/path/costsize.c b/src/backend/optimizer/path/costsize.c
index 8679b14b29..fd0ba203d5 100644
--- a/src/backend/optimizer/path/costsize.c
+++ b/src/backend/optimizer/path/costsize.c
@@ -121,6 +121,7 @@ bool enable_indexonlyscan = true;
bool enable_bitmapscan = true;
bool enable_tidscan = true;
bool enable_sort = true;
+bool enable_incrementalsort = true;
bool enable_hashagg = true;
bool enable_nestloop = true;
bool enable_material = true;
@@ -1605,6 +1606,13 @@ cost_recursive_union(Path *runion, Path *nrterm, Path *rterm)
* Determines and returns the cost of sorting a relation, including
* the cost of reading the input data.
*
+ * Sort could be either full sort of relation or incremental sort when we already
+ * have data presorted by some of required pathkeys. In the second case
+ * we estimate number of groups which source data is divided to by presorted
+ * pathkeys. And then estimate cost of sorting each individual group assuming
+ * data is divided into group uniformly. Also, if LIMIT is specified then
+ * we have to pull from source and sort only some of total groups.
+ *
* If the total volume of data to sort is less than sort_mem, we will do
* an in-memory sort, which requires no I/O and about t*log2(t) tuple
* comparisons for t tuples.
@@ -1631,7 +1639,9 @@ cost_recursive_union(Path *runion, Path *nrterm, Path *rterm)
* work that has to be done to prepare the inputs to the comparison operators.
*
* 'pathkeys' is a list of sort keys
- * 'input_cost' is the total cost for reading the input data
+ * 'presorted_keys' is a number of pathkeys already presorted in given path
+ * 'input_startup_cost' is the startup cost for reading the input data
+ * 'input_total_cost' is the total cost for reading the input data
* 'tuples' is the number of tuples in the relation
* 'width' is the average tuple width in bytes
* 'comparison_cost' is the extra cost per comparison, if any
@@ -1647,19 +1657,28 @@ cost_recursive_union(Path *runion, Path *nrterm, Path *rterm)
*/
void
cost_sort(Path *path, PlannerInfo *root,
- List *pathkeys, Cost input_cost, double tuples, int width,
- Cost comparison_cost, int sort_mem,
+ List *pathkeys, int presorted_keys,
+ Cost input_startup_cost, Cost input_total_cost,
+ double tuples, int width, Cost comparison_cost, int sort_mem,
double limit_tuples)
{
- Cost startup_cost = input_cost;
- Cost run_cost = 0;
+ Cost startup_cost = input_startup_cost;
+ Cost run_cost = 0,
+ rest_cost,
+ group_cost,
+ input_run_cost = input_total_cost - input_startup_cost;
double input_bytes = relation_byte_size(tuples, width);
double output_bytes;
double output_tuples;
+ double num_groups,
+ group_input_bytes,
+ group_tuples;
long sort_mem_bytes = sort_mem * 1024L;
if (!enable_sort)
startup_cost += disable_cost;
+ if (!enable_incrementalsort)
+ presorted_keys = 0;
path->rows = tuples;
@@ -1685,13 +1704,50 @@ cost_sort(Path *path, PlannerInfo *root,
output_bytes = input_bytes;
}
- if (output_bytes > sort_mem_bytes)
+ /*
+ * Estimate number of groups which dataset is divided by presorted keys.
+ */
+ if (presorted_keys > 0)
+ {
+ List *presortedExprs = NIL;
+ ListCell *l;
+ int i = 0;
+
+ /* Extract presorted keys as list of expressions */
+ foreach(l, pathkeys)
+ {
+ PathKey *key = (PathKey *)lfirst(l);
+ EquivalenceMember *member = (EquivalenceMember *)
+ linitial(key->pk_eclass->ec_members);
+
+ presortedExprs = lappend(presortedExprs, member->em_expr);
+
+ i++;
+ if (i >= presorted_keys)
+ break;
+ }
+
+ /* Estimate number of groups with equal presorted keys */
+ num_groups = estimate_num_groups(root, presortedExprs, tuples, NULL);
+ }
+ else
+ {
+ num_groups = 1.0;
+ }
+
+ /*
+ * Estimate average cost of sorting of one group where presorted keys are
+ * equal.
+ */
+ group_input_bytes = input_bytes / num_groups;
+ group_tuples = tuples / num_groups;
+ if (output_bytes > sort_mem_bytes && group_input_bytes > sort_mem_bytes)
{
/*
* We'll have to use a disk-based sort of all the tuples
*/
- double npages = ceil(input_bytes / BLCKSZ);
- double nruns = input_bytes / sort_mem_bytes;
+ double npages = ceil(group_input_bytes / BLCKSZ);
+ double nruns = group_input_bytes / sort_mem_bytes;
double mergeorder = tuplesort_merge_order(sort_mem_bytes);
double log_runs;
double npageaccesses;
@@ -1701,7 +1757,7 @@ cost_sort(Path *path, PlannerInfo *root,
*
* Assume about N log2 N comparisons
*/
- startup_cost += comparison_cost * tuples * LOG2(tuples);
+ group_cost = comparison_cost * group_tuples * LOG2(group_tuples);
/* Disk costs */
@@ -1712,10 +1768,10 @@ cost_sort(Path *path, PlannerInfo *root,
log_runs = 1.0;
npageaccesses = 2.0 * npages * log_runs;
/* Assume 3/4ths of accesses are sequential, 1/4th are not */
- startup_cost += npageaccesses *
+ group_cost += npageaccesses *
(seq_page_cost * 0.75 + random_page_cost * 0.25);
}
- else if (tuples > 2 * output_tuples || input_bytes > sort_mem_bytes)
+ else if (group_tuples > 2 * output_tuples || group_input_bytes > sort_mem_bytes)
{
/*
* We'll use a bounded heap-sort keeping just K tuples in memory, for
@@ -1723,14 +1779,33 @@ cost_sort(Path *path, PlannerInfo *root,
* factor is a bit higher than for quicksort. Tweak it so that the
* cost curve is continuous at the crossover point.
*/
- startup_cost += comparison_cost * tuples * LOG2(2.0 * output_tuples);
+ group_cost = comparison_cost * group_tuples * LOG2(2.0 * output_tuples);
}
else
{
- /* We'll use plain quicksort on all the input tuples */
- startup_cost += comparison_cost * tuples * LOG2(tuples);
+ /*
+ * We'll use plain quicksort on all the input tuples. If it appears
+ * that we expect less than two tuples per sort group then assume
+ * logarithmic part of estimate to be 1.
+ */
+ if (group_tuples >= 2.0)
+ group_cost = comparison_cost * group_tuples * LOG2(group_tuples);
+ else
+ group_cost = comparison_cost * group_tuples;
}
+ /* Add per group cost of fetching tuples from input */
+ group_cost += input_run_cost / num_groups;
+
+ /*
+ * We've to sort first group to start output from node. Sorting rest of
+ * groups are required to return all the other tuples.
+ */
+ startup_cost += group_cost;
+ rest_cost = (num_groups * (output_tuples / tuples) - 1.0) * group_cost;
+ if (rest_cost > 0.0)
+ run_cost += rest_cost;
+
/*
* Also charge a small amount (arbitrarily set equal to operator cost) per
* extracted tuple. We don't charge cpu_tuple_cost because a Sort node
@@ -1741,6 +1816,20 @@ cost_sort(Path *path, PlannerInfo *root,
*/
run_cost += cpu_operator_cost * tuples;
+ /* Extra costs of incremental sort */
+ if (presorted_keys > 0)
+ {
+ /*
+ * In incremental sort case we also have to cost the detection of
+ * sort groups. This turns out to be one extra copy and comparison
+ * per tuple.
+ */
+ run_cost += (cpu_tuple_cost + comparison_cost) * tuples;
+
+ /* Cost of per group tuplesort reset */
+ run_cost += 2.0 * cpu_tuple_cost * num_groups;
+ }
+
path->startup_cost = startup_cost;
path->total_cost = startup_cost + run_cost;
}
@@ -2717,6 +2806,8 @@ initial_cost_mergejoin(PlannerInfo *root, JoinCostWorkspace *workspace,
cost_sort(&sort_path,
root,
outersortkeys,
+ pathkeys_common(outer_path->pathkeys, outersortkeys),
+ outer_path->startup_cost,
outer_path->total_cost,
outer_path_rows,
outer_path->pathtarget->width,
@@ -2743,6 +2834,8 @@ initial_cost_mergejoin(PlannerInfo *root, JoinCostWorkspace *workspace,
cost_sort(&sort_path,
root,
innersortkeys,
+ pathkeys_common(inner_path->pathkeys, innersortkeys),
+ inner_path->startup_cost,
inner_path->total_cost,
inner_path_rows,
inner_path->pathtarget->width,
diff --git a/src/backend/optimizer/path/pathkeys.c b/src/backend/optimizer/path/pathkeys.c
index ef58cff28d..329ba7b532 100644
--- a/src/backend/optimizer/path/pathkeys.c
+++ b/src/backend/optimizer/path/pathkeys.c
@@ -22,10 +22,12 @@
#include "nodes/nodeFuncs.h"
#include "nodes/plannodes.h"
#include "optimizer/clauses.h"
+#include "optimizer/cost.h"
#include "optimizer/pathnode.h"
#include "optimizer/paths.h"
#include "optimizer/tlist.h"
#include "utils/lsyscache.h"
+#include "utils/selfuncs.h"
static bool pathkey_is_redundant(PathKey *new_pathkey, List *pathkeys);
@@ -308,6 +310,33 @@ compare_pathkeys(List *keys1, List *keys2)
return PATHKEYS_EQUAL;
}
+
+/*
+ * pathkeys_common
+ * Returns length of longest common prefix of keys1 and keys2.
+ */
+int
+pathkeys_common(List *keys1, List *keys2)
+{
+ int n;
+ ListCell *key1,
+ *key2;
+ n = 0;
+
+ forboth(key1, keys1, key2, keys2)
+ {
+ PathKey *pathkey1 = (PathKey *) lfirst(key1);
+ PathKey *pathkey2 = (PathKey *) lfirst(key2);
+
+ if (pathkey1 != pathkey2)
+ return n;
+ n++;
+ }
+
+ return n;
+}
+
+
/*
* pathkeys_contained_in
* Common special case of compare_pathkeys: we just want to know
@@ -1488,26 +1517,42 @@ right_merge_direction(PlannerInfo *root, PathKey *pathkey)
* Count the number of pathkeys that are useful for meeting the
* query's requested output ordering.
*
- * Unlike merge pathkeys, this is an all-or-nothing affair: it does us
- * no good to order by just the first key(s) of the requested ordering.
- * So the result is always either 0 or list_length(root->query_pathkeys).
+ * Returns number of pathkeys that maches given argument. Others can be
+ * satisfied by incremental sort.
*/
-static int
-pathkeys_useful_for_ordering(PlannerInfo *root, List *pathkeys)
+int
+pathkeys_useful_for_ordering(List *query_pathkeys, List *pathkeys)
{
- if (root->query_pathkeys == NIL)
+ int n_common_pathkeys;
+
+ if (query_pathkeys == NIL)
return 0; /* no special ordering requested */
if (pathkeys == NIL)
return 0; /* unordered path */
- if (pathkeys_contained_in(root->query_pathkeys, pathkeys))
+ n_common_pathkeys = pathkeys_common(query_pathkeys, pathkeys);
+
+ if (enable_incrementalsort)
{
- /* It's useful ... or at least the first N keys are */
- return list_length(root->query_pathkeys);
+ /*
+ * Return the number of path keys in common, or 0 if there are none. Any
+ * first common pathkeys could be useful for ordering because we can use
+ * incremental sort.
+ */
+ return n_common_pathkeys;
+ }
+ else
+ {
+ /*
+ * When incremental sort is disabled, pathkeys are useful only when they
+ * do contain all the query pathkeys.
+ */
+ if (n_common_pathkeys == list_length(query_pathkeys))
+ return n_common_pathkeys;
+ else
+ return 0;
}
-
- return 0; /* path ordering not useful */
}
/*
@@ -1523,7 +1568,7 @@ truncate_useless_pathkeys(PlannerInfo *root,
int nuseful2;
nuseful = pathkeys_useful_for_merging(root, rel, pathkeys);
- nuseful2 = pathkeys_useful_for_ordering(root, pathkeys);
+ nuseful2 = pathkeys_useful_for_ordering(root->query_pathkeys, pathkeys);
if (nuseful2 > nuseful)
nuseful = nuseful2;
diff --git a/src/backend/optimizer/plan/createplan.c b/src/backend/optimizer/plan/createplan.c
index e599283d6b..133435f516 100644
--- a/src/backend/optimizer/plan/createplan.c
+++ b/src/backend/optimizer/plan/createplan.c
@@ -236,7 +236,7 @@ static MergeJoin *make_mergejoin(List *tlist,
Plan *lefttree, Plan *righttree,
JoinType jointype, bool inner_unique,
bool skip_mark_restore);
-static Sort *make_sort(Plan *lefttree, int numCols,
+static Sort *make_sort(Plan *lefttree, int numCols, int skipCols,
AttrNumber *sortColIdx, Oid *sortOperators,
Oid *collations, bool *nullsFirst);
static Plan *prepare_sort_from_pathkeys(Plan *lefttree, List *pathkeys,
@@ -252,10 +252,11 @@ static EquivalenceMember *find_ec_member_for_tle(EquivalenceClass *ec,
TargetEntry *tle,
Relids relids);
static Sort *make_sort_from_pathkeys(Plan *lefttree, List *pathkeys,
- Relids relids);
+ Relids relids, int skipCols);
static Sort *make_sort_from_groupcols(List *groupcls,
AttrNumber *grpColIdx,
- Plan *lefttree);
+ Plan *lefttree,
+ int skipCols);
static Material *make_material(Plan *lefttree);
static WindowAgg *make_windowagg(List *tlist, Index winref,
int partNumCols, AttrNumber *partColIdx, Oid *partOperators,
@@ -437,6 +438,7 @@ create_plan_recurse(PlannerInfo *root, Path *best_path, int flags)
(GatherPath *) best_path);
break;
case T_Sort:
+ case T_IncrementalSort:
plan = (Plan *) create_sort_plan(root,
(SortPath *) best_path,
flags);
@@ -1122,6 +1124,7 @@ create_merge_append_plan(PlannerInfo *root, MergeAppendPath *best_path)
Oid *sortOperators;
Oid *collations;
bool *nullsFirst;
+ int n_common_pathkeys;
/* Build the child plan */
/* Must insist that all children return the same tlist */
@@ -1156,9 +1159,11 @@ create_merge_append_plan(PlannerInfo *root, MergeAppendPath *best_path)
numsortkeys * sizeof(bool)) == 0);
/* Now, insert a Sort node if subplan isn't sufficiently ordered */
- if (!pathkeys_contained_in(pathkeys, subpath->pathkeys))
+ n_common_pathkeys = pathkeys_common(pathkeys, subpath->pathkeys);
+ if (n_common_pathkeys < list_length(pathkeys))
{
Sort *sort = make_sort(subplan, numsortkeys,
+ n_common_pathkeys,
sortColIdx, sortOperators,
collations, nullsFirst);
@@ -1508,6 +1513,7 @@ create_gather_merge_plan(PlannerInfo *root, GatherMergePath *best_path)
Plan *subplan;
List *pathkeys = best_path->path.pathkeys;
List *tlist = build_path_tlist(root, &best_path->path);
+ int n_common_pathkeys;
/* As with Gather, it's best to project away columns in the workers. */
subplan = create_plan_recurse(root, best_path->subpath, CP_EXACT_TLIST);
@@ -1537,12 +1543,16 @@ create_gather_merge_plan(PlannerInfo *root, GatherMergePath *best_path)
/* Now, insert a Sort node if subplan isn't sufficiently ordered */
- if (!pathkeys_contained_in(pathkeys, best_path->subpath->pathkeys))
+ n_common_pathkeys = pathkeys_common(pathkeys, best_path->subpath->pathkeys);
+ if (n_common_pathkeys < list_length(pathkeys))
+ {
subplan = (Plan *) make_sort(subplan, gm_plan->numCols,
+ n_common_pathkeys,
gm_plan->sortColIdx,
gm_plan->sortOperators,
gm_plan->collations,
gm_plan->nullsFirst);
+ }
/* Now insert the subplan under GatherMerge. */
gm_plan->plan.lefttree = subplan;
@@ -1655,6 +1665,7 @@ create_sort_plan(PlannerInfo *root, SortPath *best_path, int flags)
{
Sort *plan;
Plan *subplan;
+ int n_common_pathkeys;
/*
* We don't want any excess columns in the sorted tuples, so request a
@@ -1664,7 +1675,13 @@ create_sort_plan(PlannerInfo *root, SortPath *best_path, int flags)
subplan = create_plan_recurse(root, best_path->subpath,
flags | CP_SMALL_TLIST);
- plan = make_sort_from_pathkeys(subplan, best_path->path.pathkeys, NULL);
+ if (IsA(best_path, IncrementalSortPath))
+ n_common_pathkeys = ((IncrementalSortPath *) best_path)->skipCols;
+ else
+ n_common_pathkeys = 0;
+
+ plan = make_sort_from_pathkeys(subplan, best_path->path.pathkeys,
+ NULL, n_common_pathkeys);
copy_generic_path_info(&plan->plan, (Path *) best_path);
@@ -1908,7 +1925,8 @@ create_groupingsets_plan(PlannerInfo *root, GroupingSetsPath *best_path)
sort_plan = (Plan *)
make_sort_from_groupcols(rollup->groupClause,
new_grpColIdx,
- subplan);
+ subplan,
+ 0);
}
if (!rollup->is_hashed)
@@ -3848,10 +3866,15 @@ create_mergejoin_plan(PlannerInfo *root,
*/
if (best_path->outersortkeys)
{
+ Sort *sort;
+ int n_common_pathkeys;
Relids outer_relids = outer_path->parent->relids;
- Sort *sort = make_sort_from_pathkeys(outer_plan,
- best_path->outersortkeys,
- outer_relids);
+
+ n_common_pathkeys = pathkeys_common(best_path->outersortkeys,
+ best_path->jpath.outerjoinpath->pathkeys);
+
+ sort = make_sort_from_pathkeys(outer_plan, best_path->outersortkeys,
+ outer_relids, n_common_pathkeys);
label_sort_with_costsize(root, sort, -1.0);
outer_plan = (Plan *) sort;
@@ -3862,10 +3885,15 @@ create_mergejoin_plan(PlannerInfo *root,
if (best_path->innersortkeys)
{
+ Sort *sort;
+ int n_common_pathkeys;
Relids inner_relids = inner_path->parent->relids;
- Sort *sort = make_sort_from_pathkeys(inner_plan,
- best_path->innersortkeys,
- inner_relids);
+
+ n_common_pathkeys = pathkeys_common(best_path->innersortkeys,
+ best_path->jpath.innerjoinpath->pathkeys);
+
+ sort = make_sort_from_pathkeys(inner_plan, best_path->innersortkeys,
+ inner_relids, n_common_pathkeys);
label_sort_with_costsize(root, sort, -1.0);
inner_plan = (Plan *) sort;
@@ -4927,8 +4955,13 @@ label_sort_with_costsize(PlannerInfo *root, Sort *plan, double limit_tuples)
{
Plan *lefttree = plan->plan.lefttree;
Path sort_path; /* dummy for result of cost_sort */
+ int skip_cols = 0;
+
+ if (IsA(plan, IncrementalSort))
+ skip_cols = ((IncrementalSort *) plan)->skipCols;
- cost_sort(&sort_path, root, NIL,
+ cost_sort(&sort_path, root, NIL, skip_cols,
+ lefttree->startup_cost,
lefttree->total_cost,
lefttree->plan_rows,
lefttree->plan_width,
@@ -5519,13 +5552,31 @@ make_mergejoin(List *tlist,
* nullsFirst arrays already.
*/
static Sort *
-make_sort(Plan *lefttree, int numCols,
+make_sort(Plan *lefttree, int numCols, int skipCols,
AttrNumber *sortColIdx, Oid *sortOperators,
Oid *collations, bool *nullsFirst)
{
- Sort *node = makeNode(Sort);
- Plan *plan = &node->plan;
+ Sort *node;
+ Plan *plan;
+
+ /* Always use regular sort node when enable_incrementalsort = false */
+ if (!enable_incrementalsort)
+ skipCols = 0;
+
+ if (skipCols == 0)
+ {
+ node = makeNode(Sort);
+ }
+ else
+ {
+ IncrementalSort *incrementalSort;
+
+ incrementalSort = makeNode(IncrementalSort);
+ node = &incrementalSort->sort;
+ incrementalSort->skipCols = skipCols;
+ }
+ plan = &node->plan;
plan->targetlist = lefttree->targetlist;
plan->qual = NIL;
plan->lefttree = lefttree;
@@ -5858,9 +5909,11 @@ find_ec_member_for_tle(EquivalenceClass *ec,
* 'lefttree' is the node which yields input tuples
* 'pathkeys' is the list of pathkeys by which the result is to be sorted
* 'relids' is the set of relations required by prepare_sort_from_pathkeys()
+ * 'skipCols' is the number of presorted columns in input tuples
*/
static Sort *
-make_sort_from_pathkeys(Plan *lefttree, List *pathkeys, Relids relids)
+make_sort_from_pathkeys(Plan *lefttree, List *pathkeys,
+ Relids relids, int skipCols)
{
int numsortkeys;
AttrNumber *sortColIdx;
@@ -5880,7 +5933,7 @@ make_sort_from_pathkeys(Plan *lefttree, List *pathkeys, Relids relids)
&nullsFirst);
/* Now build the Sort node */
- return make_sort(lefttree, numsortkeys,
+ return make_sort(lefttree, numsortkeys, skipCols,
sortColIdx, sortOperators,
collations, nullsFirst);
}
@@ -5923,7 +5976,7 @@ make_sort_from_sortclauses(List *sortcls, Plan *lefttree)
numsortkeys++;
}
- return make_sort(lefttree, numsortkeys,
+ return make_sort(lefttree, numsortkeys, 0,
sortColIdx, sortOperators,
collations, nullsFirst);
}
@@ -5944,7 +5997,8 @@ make_sort_from_sortclauses(List *sortcls, Plan *lefttree)
static Sort *
make_sort_from_groupcols(List *groupcls,
AttrNumber *grpColIdx,
- Plan *lefttree)
+ Plan *lefttree,
+ int skipCols)
{
List *sub_tlist = lefttree->targetlist;
ListCell *l;
@@ -5977,7 +6031,7 @@ make_sort_from_groupcols(List *groupcls,
numsortkeys++;
}
- return make_sort(lefttree, numsortkeys,
+ return make_sort(lefttree, numsortkeys, skipCols,
sortColIdx, sortOperators,
collations, nullsFirst);
}
@@ -6633,6 +6687,7 @@ is_projection_capable_plan(Plan *plan)
case T_Hash:
case T_Material:
case T_Sort:
+ case T_IncrementalSort:
case T_Unique:
case T_SetOp:
case T_LockRows:
diff --git a/src/backend/optimizer/plan/planagg.c b/src/backend/optimizer/plan/planagg.c
index 95cbffbd69..308f60beac 100644
--- a/src/backend/optimizer/plan/planagg.c
+++ b/src/backend/optimizer/plan/planagg.c
@@ -44,6 +44,7 @@
#include "parser/parse_clause.h"
#include "rewrite/rewriteManip.h"
#include "utils/lsyscache.h"
+#include "utils/selfuncs.h"
#include "utils/syscache.h"
diff --git a/src/backend/optimizer/plan/planner.c b/src/backend/optimizer/plan/planner.c
index 7b52dadd81..3842271245 100644
--- a/src/backend/optimizer/plan/planner.c
+++ b/src/backend/optimizer/plan/planner.c
@@ -3849,14 +3849,14 @@ create_grouping_paths(PlannerInfo *root,
foreach(lc, input_rel->partial_pathlist)
{
Path *path = (Path *) lfirst(lc);
- bool is_sorted;
+ int n_useful_pathkeys;
- is_sorted = pathkeys_contained_in(root->group_pathkeys,
- path->pathkeys);
- if (path == cheapest_partial_path || is_sorted)
+ n_useful_pathkeys = pathkeys_useful_for_ordering(
+ root->group_pathkeys, path->pathkeys);
+ if (path == cheapest_partial_path || n_useful_pathkeys > 0)
{
/* Sort the cheapest partial path, if it isn't already */
- if (!is_sorted)
+ if (n_useful_pathkeys < list_length(root->group_pathkeys))
path = (Path *) create_sort_path(root,
grouped_rel,
path,
@@ -3929,14 +3929,14 @@ create_grouping_paths(PlannerInfo *root,
foreach(lc, input_rel->pathlist)
{
Path *path = (Path *) lfirst(lc);
- bool is_sorted;
+ int n_useful_pathkeys;
- is_sorted = pathkeys_contained_in(root->group_pathkeys,
- path->pathkeys);
- if (path == cheapest_path || is_sorted)
+ n_useful_pathkeys = pathkeys_useful_for_ordering(
+ root->group_pathkeys, path->pathkeys);
+ if (path == cheapest_path || n_useful_pathkeys > 0)
{
/* Sort the cheapest-total path if it isn't already sorted */
- if (!is_sorted)
+ if (n_useful_pathkeys < list_length(root->group_pathkeys))
path = (Path *) create_sort_path(root,
grouped_rel,
path,
@@ -5003,13 +5003,13 @@ create_ordered_paths(PlannerInfo *root,
foreach(lc, input_rel->pathlist)
{
Path *path = (Path *) lfirst(lc);
- bool is_sorted;
+ int n_useful_pathkeys;
- is_sorted = pathkeys_contained_in(root->sort_pathkeys,
- path->pathkeys);
- if (path == cheapest_input_path || is_sorted)
+ n_useful_pathkeys = pathkeys_useful_for_ordering(root->sort_pathkeys,
+ path->pathkeys);
+ if (path == cheapest_input_path || n_useful_pathkeys > 0)
{
- if (!is_sorted)
+ if (n_useful_pathkeys < list_length(root->sort_pathkeys))
{
/* An explicit sort here can take advantage of LIMIT */
path = (Path *) create_sort_path(root,
@@ -6139,8 +6139,9 @@ plan_cluster_use_sort(Oid tableOid, Oid indexOid)
/* Estimate the cost of seq scan + sort */
seqScanPath = create_seqscan_path(root, rel, NULL, 0);
- cost_sort(&seqScanAndSortPath, root, NIL,
- seqScanPath->total_cost, rel->tuples, rel->reltarget->width,
+ cost_sort(&seqScanAndSortPath, root, NIL, 0,
+ seqScanPath->startup_cost, seqScanPath->total_cost,
+ rel->tuples, rel->reltarget->width,
comparisonCost, maintenance_work_mem, -1.0);
/* Estimate the cost of index scan */
diff --git a/src/backend/optimizer/plan/setrefs.c b/src/backend/optimizer/plan/setrefs.c
index 4617d12cb9..be520e6086 100644
--- a/src/backend/optimizer/plan/setrefs.c
+++ b/src/backend/optimizer/plan/setrefs.c
@@ -642,6 +642,7 @@ set_plan_refs(PlannerInfo *root, Plan *plan, int rtoffset)
case T_Hash:
case T_Material:
case T_Sort:
+ case T_IncrementalSort:
case T_Unique:
case T_SetOp:
diff --git a/src/backend/optimizer/plan/subselect.c b/src/backend/optimizer/plan/subselect.c
index 46367cba63..616ad1a474 100644
--- a/src/backend/optimizer/plan/subselect.c
+++ b/src/backend/optimizer/plan/subselect.c
@@ -2782,6 +2782,7 @@ finalize_plan(PlannerInfo *root, Plan *plan,
case T_Hash:
case T_Material:
case T_Sort:
+ case T_IncrementalSort:
case T_Unique:
case T_SetOp:
case T_Group:
diff --git a/src/backend/optimizer/prep/prepunion.c b/src/backend/optimizer/prep/prepunion.c
index 5a08e75ad5..eb95ca4c5e 100644
--- a/src/backend/optimizer/prep/prepunion.c
+++ b/src/backend/optimizer/prep/prepunion.c
@@ -983,7 +983,8 @@ choose_hashed_setop(PlannerInfo *root, List *groupClauses,
sorted_p.startup_cost = input_path->startup_cost;
sorted_p.total_cost = input_path->total_cost;
/* XXX cost_sort doesn't actually look at pathkeys, so just pass NIL */
- cost_sort(&sorted_p, root, NIL, sorted_p.total_cost,
+ cost_sort(&sorted_p, root, NIL, 0,
+ sorted_p.startup_cost, sorted_p.total_cost,
input_path->rows, input_path->pathtarget->width,
0.0, work_mem, -1.0);
cost_group(&sorted_p, root, numGroupCols, dNumGroups,
diff --git a/src/backend/optimizer/util/pathnode.c b/src/backend/optimizer/util/pathnode.c
index 7df8761710..9c6f910f14 100644
--- a/src/backend/optimizer/util/pathnode.c
+++ b/src/backend/optimizer/util/pathnode.c
@@ -105,7 +105,7 @@ compare_path_costs(Path *path1, Path *path2, CostSelector criterion)
}
/*
- * compare_path_fractional_costs
+ * compare_fractional_path_costs
* Return -1, 0, or +1 according as path1 is cheaper, the same cost,
* or more expensive than path2 for fetching the specified fraction
* of the total tuples.
@@ -1356,12 +1356,13 @@ create_merge_append_path(PlannerInfo *root,
foreach(l, subpaths)
{
Path *subpath = (Path *) lfirst(l);
+ int n_common_pathkeys = pathkeys_common(pathkeys, subpath->pathkeys);
pathnode->path.rows += subpath->rows;
pathnode->path.parallel_safe = pathnode->path.parallel_safe &&
subpath->parallel_safe;
- if (pathkeys_contained_in(pathkeys, subpath->pathkeys))
+ if (n_common_pathkeys == list_length(pathkeys))
{
/* Subpath is adequately ordered, we won't need to sort it */
input_startup_cost += subpath->startup_cost;
@@ -1375,6 +1376,8 @@ create_merge_append_path(PlannerInfo *root,
cost_sort(&sort_path,
root,
pathkeys,
+ n_common_pathkeys,
+ subpath->startup_cost,
subpath->total_cost,
subpath->parent->tuples,
subpath->pathtarget->width,
@@ -1622,7 +1625,8 @@ create_unique_path(PlannerInfo *root, RelOptInfo *rel, Path *subpath,
/*
* Estimate cost for sort+unique implementation
*/
- cost_sort(&sort_path, root, NIL,
+ cost_sort(&sort_path, root, NIL, 0,
+ subpath->startup_cost,
subpath->total_cost,
rel->rows,
subpath->pathtarget->width,
@@ -1715,6 +1719,7 @@ create_gather_merge_path(PlannerInfo *root, RelOptInfo *rel, Path *subpath,
GatherMergePath *pathnode = makeNode(GatherMergePath);
Cost input_startup_cost = 0;
Cost input_total_cost = 0;
+ int n_common_pathkeys;
Assert(subpath->parallel_safe);
Assert(pathkeys);
@@ -1731,7 +1736,9 @@ create_gather_merge_path(PlannerInfo *root, RelOptInfo *rel, Path *subpath,
pathnode->path.pathtarget = target ? target : rel->reltarget;
pathnode->path.rows += subpath->rows;
- if (pathkeys_contained_in(pathkeys, subpath->pathkeys))
+ n_common_pathkeys = pathkeys_common(pathkeys, subpath->pathkeys);
+
+ if (n_common_pathkeys == list_length(pathkeys))
{
/* Subpath is adequately ordered, we won't need to sort it */
input_startup_cost += subpath->startup_cost;
@@ -1745,6 +1752,8 @@ create_gather_merge_path(PlannerInfo *root, RelOptInfo *rel, Path *subpath,
cost_sort(&sort_path,
root,
pathkeys,
+ n_common_pathkeys,
+ subpath->startup_cost,
subpath->total_cost,
subpath->rows,
subpath->pathtarget->width,
@@ -2604,9 +2613,31 @@ create_sort_path(PlannerInfo *root,
List *pathkeys,
double limit_tuples)
{
- SortPath *pathnode = makeNode(SortPath);
+ SortPath *pathnode;
+ int n_common_pathkeys;
+
+ if (enable_incrementalsort)
+ n_common_pathkeys = pathkeys_common(subpath->pathkeys, pathkeys);
+ else
+ n_common_pathkeys = 0;
+
+ if (n_common_pathkeys == 0)
+ {
+ pathnode = makeNode(SortPath);
+ pathnode->path.pathtype = T_Sort;
+ }
+ else
+ {
+ IncrementalSortPath *incpathnode;
+
+ incpathnode = makeNode(IncrementalSortPath);
+ pathnode = &incpathnode->spath;
+ pathnode->path.pathtype = T_IncrementalSort;
+ incpathnode->skipCols = n_common_pathkeys;
+ }
+
+ Assert(n_common_pathkeys < list_length(pathkeys));
- pathnode->path.pathtype = T_Sort;
pathnode->path.parent = rel;
/* Sort doesn't project, so use source path's pathtarget */
pathnode->path.pathtarget = subpath->pathtarget;
@@ -2620,7 +2651,9 @@ create_sort_path(PlannerInfo *root,
pathnode->subpath = subpath;
- cost_sort(&pathnode->path, root, pathkeys,
+ cost_sort(&pathnode->path, root,
+ pathkeys, n_common_pathkeys,
+ subpath->startup_cost,
subpath->total_cost,
subpath->rows,
subpath->pathtarget->width,
@@ -2932,7 +2965,8 @@ create_groupingsets_path(PlannerInfo *root,
else
{
/* Account for cost of sort, but don't charge input cost again */
- cost_sort(&sort_path, root, NIL,
+ cost_sort(&sort_path, root, NIL, 0,
+ 0.0,
0.0,
subpath->rows,
subpath->pathtarget->width,
diff --git a/src/backend/utils/adt/orderedsetaggs.c b/src/backend/utils/adt/orderedsetaggs.c
index 79dbfd1a05..e3e984b3da 100644
--- a/src/backend/utils/adt/orderedsetaggs.c
+++ b/src/backend/utils/adt/orderedsetaggs.c
@@ -291,7 +291,8 @@ ordered_set_startup(FunctionCallInfo fcinfo, bool use_tuples)
qstate->sortCollations,
qstate->sortNullsFirsts,
work_mem,
- qstate->rescan_needed);
+ qstate->rescan_needed,
+ false);
else
osastate->sortstate = tuplesort_begin_datum(qstate->sortColType,
qstate->sortOperator,
diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c
index fcc8323f62..4726bee850 100644
--- a/src/backend/utils/adt/selfuncs.c
+++ b/src/backend/utils/adt/selfuncs.c
@@ -3714,6 +3714,42 @@ estimate_num_groups(PlannerInfo *root, List *groupExprs, double input_rows,
return numdistinct;
}
+/*
+ * estimate_pathkeys_groups - Estimate number of groups which dataset is
+ * divided to by pathkeys.
+ *
+ * Returns an array of group numbers. i'th element of array is number of groups
+ * which first i pathkeys divides dataset into. Actually is a convenience
+ * wrapper over estimate_num_groups().
+ */
+double *
+estimate_pathkeys_groups(List *pathkeys, PlannerInfo *root, double tuples)
+{
+ ListCell *l;
+ List *groupExprs = NIL;
+ double *result;
+ int i;
+
+ /*
+ * Get number of groups for each prefix of pathkeys.
+ */
+ i = 0;
+ result = (double *) palloc(sizeof(double) * list_length(pathkeys));
+ foreach(l, pathkeys)
+ {
+ PathKey *key = (PathKey *)lfirst(l);
+ EquivalenceMember *member = (EquivalenceMember *)
+ linitial(key->pk_eclass->ec_members);
+
+ groupExprs = lappend(groupExprs, member->em_expr);
+
+ result[i] = estimate_num_groups(root, groupExprs, tuples, NULL);
+ i++;
+ }
+
+ return result;
+}
+
/*
* Estimate hash bucket statistics when the specified expression is used
* as a hash key for the given number of buckets.
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index 72f6be329e..bea4f00421 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -857,6 +857,15 @@ static struct config_bool ConfigureNamesBool[] =
true,
NULL, NULL, NULL
},
+ {
+ {"enable_incrementalsort", PGC_USERSET, QUERY_TUNING_METHOD,
+ gettext_noop("Enables the planner's use of incremental sort steps."),
+ NULL
+ },
+ &enable_incrementalsort,
+ true,
+ NULL, NULL, NULL
+ },
{
{"enable_hashagg", PGC_USERSET, QUERY_TUNING_METHOD,
gettext_noop("Enables the planner's use of hashed aggregation plans."),
diff --git a/src/backend/utils/sort/tuplesort.c b/src/backend/utils/sort/tuplesort.c
index eecc66cafa..0265da312b 100644
--- a/src/backend/utils/sort/tuplesort.c
+++ b/src/backend/utils/sort/tuplesort.c
@@ -231,6 +231,13 @@ struct Tuplesortstate
int64 allowedMem; /* total memory allowed, in bytes */
int maxTapes; /* number of tapes (Knuth's T) */
int tapeRange; /* maxTapes-1 (Knuth's P) */
+ int64 maxSpace; /* maximum amount of space occupied among sort
+ of groups, either in-memory or on-disk */
+ bool maxSpaceOnDisk; /* true when maxSpace is value for on-disk
+ space, false when it's value for in-memory
+ space */
+ TupSortStatus maxSpaceStatus; /* sort status when maxSpace was reached */
+ MemoryContext maincontext;
MemoryContext sortcontext; /* memory context holding most sort data */
MemoryContext tuplecontext; /* sub-context of sortcontext for tuple data */
LogicalTapeSet *tapeset; /* logtape.c object for tapes in a temp file */
@@ -573,6 +580,9 @@ static void writetup_datum(Tuplesortstate *state, int tapenum,
static void readtup_datum(Tuplesortstate *state, SortTuple *stup,
int tapenum, unsigned int len);
static void free_sort_tuple(Tuplesortstate *state, SortTuple *stup);
+static void tuplesort_free(Tuplesortstate *state, bool delete);
+static void tuplesort_updatemax(Tuplesortstate *state);
+
/*
* Special versions of qsort just for SortTuple objects. qsort_tuple() sorts
@@ -607,18 +617,27 @@ static Tuplesortstate *
tuplesort_begin_common(int workMem, bool randomAccess)
{
Tuplesortstate *state;
+ MemoryContext maincontext;
MemoryContext sortcontext;
MemoryContext tuplecontext;
MemoryContext oldcontext;
/*
- * Create a working memory context for this sort operation. All data
- * needed by the sort will live inside this context.
+ * Memory context surviving tuplesort_reset. This memory context holds
+ * data which is useful to keep while sorting multiple similar batches.
*/
- sortcontext = AllocSetContextCreate(CurrentMemoryContext,
+ maincontext = AllocSetContextCreate(CurrentMemoryContext,
"TupleSort main",
ALLOCSET_DEFAULT_SIZES);
+ /*
+ * Create a working memory context for one sort operation. The content of
+ * this context is deleted by tuplesort_reset.
+ */
+ sortcontext = AllocSetContextCreate(maincontext,
+ "TupleSort sort",
+ ALLOCSET_DEFAULT_SIZES);
+
/*
* Caller tuple (e.g. IndexTuple) memory context.
*
@@ -636,7 +655,7 @@ tuplesort_begin_common(int workMem, bool randomAccess)
* Make the Tuplesortstate within the per-sort context. This way, we
* don't need a separate pfree() operation for it at shutdown.
*/
- oldcontext = MemoryContextSwitchTo(sortcontext);
+ oldcontext = MemoryContextSwitchTo(maincontext);
state = (Tuplesortstate *) palloc0(sizeof(Tuplesortstate));
@@ -654,6 +673,7 @@ tuplesort_begin_common(int workMem, bool randomAccess)
state->availMem = state->allowedMem;
state->sortcontext = sortcontext;
state->tuplecontext = tuplecontext;
+ state->maincontext = maincontext;
state->tapeset = NULL;
state->memtupcount = 0;
@@ -694,13 +714,14 @@ tuplesort_begin_heap(TupleDesc tupDesc,
int nkeys, AttrNumber *attNums,
Oid *sortOperators, Oid *sortCollations,
bool *nullsFirstFlags,
- int workMem, bool randomAccess)
+ int workMem, bool randomAccess,
+ bool skipAbbrev)
{
Tuplesortstate *state = tuplesort_begin_common(workMem, randomAccess);
MemoryContext oldcontext;
int i;
- oldcontext = MemoryContextSwitchTo(state->sortcontext);
+ oldcontext = MemoryContextSwitchTo(state->maincontext);
AssertArg(nkeys > 0);
@@ -742,7 +763,7 @@ tuplesort_begin_heap(TupleDesc tupDesc,
sortKey->ssup_nulls_first = nullsFirstFlags[i];
sortKey->ssup_attno = attNums[i];
/* Convey if abbreviation optimization is applicable in principle */
- sortKey->abbreviate = (i == 0);
+ sortKey->abbreviate = (i == 0) && !skipAbbrev;
PrepareSortSupportFromOrderingOp(sortOperators[i], sortKey);
}
@@ -773,7 +794,7 @@ tuplesort_begin_cluster(TupleDesc tupDesc,
Assert(indexRel->rd_rel->relam == BTREE_AM_OID);
- oldcontext = MemoryContextSwitchTo(state->sortcontext);
+ oldcontext = MemoryContextSwitchTo(state->maincontext);
#ifdef TRACE_SORT
if (trace_sort)
@@ -864,7 +885,7 @@ tuplesort_begin_index_btree(Relation heapRel,
MemoryContext oldcontext;
int i;
- oldcontext = MemoryContextSwitchTo(state->sortcontext);
+ oldcontext = MemoryContextSwitchTo(state->maincontext);
#ifdef TRACE_SORT
if (trace_sort)
@@ -939,7 +960,7 @@ tuplesort_begin_index_hash(Relation heapRel,
Tuplesortstate *state = tuplesort_begin_common(workMem, randomAccess);
MemoryContext oldcontext;
- oldcontext = MemoryContextSwitchTo(state->sortcontext);
+ oldcontext = MemoryContextSwitchTo(state->maincontext);
#ifdef TRACE_SORT
if (trace_sort)
@@ -981,7 +1002,7 @@ tuplesort_begin_datum(Oid datumType, Oid sortOperator, Oid sortCollation,
int16 typlen;
bool typbyval;
- oldcontext = MemoryContextSwitchTo(state->sortcontext);
+ oldcontext = MemoryContextSwitchTo(state->maincontext);
#ifdef TRACE_SORT
if (trace_sort)
@@ -1092,16 +1113,12 @@ tuplesort_set_bound(Tuplesortstate *state, int64 bound)
}
/*
- * tuplesort_end
- *
- * Release resources and clean up.
+ * tuplesort_free
*
- * NOTE: after calling this, any pointers returned by tuplesort_getXXX are
- * pointing to garbage. Be careful not to attempt to use or free such
- * pointers afterwards!
+ * Internal routine for freeing resources of tuplesort.
*/
-void
-tuplesort_end(Tuplesortstate *state)
+static void
+tuplesort_free(Tuplesortstate *state, bool delete)
{
/* context swap probably not needed, but let's be safe */
MemoryContext oldcontext = MemoryContextSwitchTo(state->sortcontext);
@@ -1160,7 +1177,98 @@ tuplesort_end(Tuplesortstate *state)
* Free the per-sort memory context, thereby releasing all working memory,
* including the Tuplesortstate struct itself.
*/
- MemoryContextDelete(state->sortcontext);
+ if (delete)
+ {
+ MemoryContextDelete(state->maincontext);
+ }
+ else
+ {
+ MemoryContextResetOnly(state->sortcontext);
+ MemoryContextResetOnly(state->tuplecontext);
+ }
+}
+
+/*
+ * tuplesort_end
+ *
+ * Release resources and clean up.
+ *
+ * NOTE: after calling this, any pointers returned by tuplesort_getXXX are
+ * pointing to garbage. Be careful not to attempt to use or free such
+ * pointers afterwards!
+ */
+void
+tuplesort_end(Tuplesortstate *state)
+{
+ tuplesort_free(state, true);
+}
+
+/*
+ * tuplesort_updatemax
+ *
+ * Update maximum resource usage statistics.
+ */
+static void
+tuplesort_updatemax(Tuplesortstate *state)
+{
+ int64 spaceUsed;
+ bool spaceUsedOnDisk;
+
+ /*
+ * Note: it might seem we should provide both memory and disk usage for a
+ * disk-based sort. However, the current code doesn't track memory space
+ * accurately once we have begun to return tuples to the caller (since we
+ * don't account for pfree's the caller is expected to do), so we cannot
+ * rely on availMem in a disk sort. This does not seem worth the overhead
+ * to fix. Is it worth creating an API for the memory context code to
+ * tell us how much is actually used in sortcontext?
+ */
+ if (state->tapeset)
+ {
+ spaceUsedOnDisk = true;
+ spaceUsed = LogicalTapeSetBlocks(state->tapeset) * BLCKSZ;
+ }
+ else
+ {
+ spaceUsedOnDisk = false;
+ spaceUsed = state->allowedMem - state->availMem;
+ }
+
+ if (spaceUsed > state->maxSpace)
+ {
+ state->maxSpace = spaceUsed;
+ state->maxSpaceOnDisk = spaceUsedOnDisk;
+ state->maxSpaceStatus = state->status;
+ }
+}
+
+/*
+ * tuplesort_reset
+ *
+ * Reset the tuplesort. Reset all the data in the tuplesort, but leave the
+ * meta-information in. After tuplesort_reset, tuplesort is ready to start
+ * a new sort. It allows evade recreation of tuple sort (and save resources)
+ * when sorting multiple small batches.
+ */
+void
+tuplesort_reset(Tuplesortstate *state)
+{
+ tuplesort_updatemax(state);
+ tuplesort_free(state, false);
+ state->status = TSS_INITIAL;
+ state->memtupcount = 0;
+ state->boundUsed = false;
+ state->tapeset = NULL;
+ state->currentRun = 0;
+ state->result_tape = -1;
+ state->bounded = false;
+ state->availMem = state->allowedMem;
+ state->lastReturnedTuple = NULL;
+ state->slabAllocatorUsed = false;
+ state->slabMemoryBegin = NULL;
+ state->slabMemoryEnd = NULL;
+ state->slabFreeHead = NULL;
+ USEMEM(state, GetMemoryChunkSpace(state->memtuples));
}
/*
@@ -2944,18 +3052,15 @@ tuplesort_get_stats(Tuplesortstate *state,
* to fix. Is it worth creating an API for the memory context code to
* tell us how much is actually used in sortcontext?
*/
- if (state->tapeset)
- {
+ tuplesort_updatemax(state);
+
+ if (state->maxSpaceOnDisk)
stats->spaceType = SORT_SPACE_TYPE_DISK;
- stats->spaceUsed = LogicalTapeSetBlocks(state->tapeset) * (BLCKSZ / 1024);
- }
else
- {
stats->spaceType = SORT_SPACE_TYPE_MEMORY;
- stats->spaceUsed = (state->allowedMem - state->availMem + 1023) / 1024;
- }
+ stats->spaceUsed = (state->maxSpace + 1023) / 1024;
- switch (state->status)
+ switch (state->maxSpaceStatus)
{
case TSS_SORTEDINMEM:
if (state->boundUsed)
diff --git a/src/include/executor/nodeIncrementalSort.h b/src/include/executor/nodeIncrementalSort.h
new file mode 100644
index 0000000000..a9b562843d
--- /dev/null
+++ b/src/include/executor/nodeIncrementalSort.h
@@ -0,0 +1,31 @@
+/*-------------------------------------------------------------------------
+ *
+ * nodeIncrementalSort.h
+ *
+ *
+ *
+ * Portions Copyright (c) 1996-2018, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/include/executor/nodeIncrementalSort.h
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef NODEINCREMENTALSORT_H
+#define NODEINCREMENTALSORT_H
+
+#include "access/parallel.h"
+#include "nodes/execnodes.h"
+
+extern IncrementalSortState *ExecInitIncrementalSort(IncrementalSort *node, EState *estate, int eflags);
+extern void ExecEndIncrementalSort(IncrementalSortState *node);
+extern void ExecReScanIncrementalSort(IncrementalSortState *node);
+
+/* parallel instrumentation support */
+extern void ExecIncrementalSortEstimate(IncrementalSortState *node, ParallelContext *pcxt);
+extern void ExecIncrementalSortInitializeDSM(IncrementalSortState *node, ParallelContext *pcxt);
+extern void ExecIncrementalSortReInitializeDSM(IncrementalSortState *node, ParallelContext *pcxt);
+extern void ExecIncrementalSortInitializeWorker(IncrementalSortState *node, ParallelWorkerContext *pcxt);
+extern void ExecIncrementalSortRetrieveInstrumentation(IncrementalSortState *node);
+
+#endif /* NODEINCREMENTALSORT_H */
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 2a4f7407a1..4180f57e88 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -1754,6 +1754,20 @@ typedef struct MaterialState
Tuplestorestate *tuplestorestate;
} MaterialState;
+
+/* ----------------
+ * When performing sorting by multiple keys input dataset could be already
+ * presorted by some prefix of these keys. We call them "skip keys".
+ * SkipKeyData represents information about one such key.
+ * ----------------
+ */
+typedef struct SkipKeyData
+{
+ FmgrInfo flinfo; /* comparison function info */
+ FunctionCallInfoData fcinfo; /* comparison function call info */
+ OffsetNumber attno; /* attribute number in tuple */
+} SkipKeyData;
+
/* ----------------
* Shared memory container for per-worker sort information
* ----------------
@@ -1782,6 +1796,44 @@ typedef struct SortState
SharedSortInfo *shared_info; /* one entry per worker */
} SortState;
+/* ----------------
+ * Shared memory container for per-worker incremental sort information
+ * ----------------
+ */
+typedef struct IncrementalSortInfo
+{
+ TuplesortInstrumentation sinstrument;
+ int64 groupsCount;
+} IncrementalSortInfo;
+
+typedef struct SharedIncrementalSortInfo
+{
+ int num_workers;
+ IncrementalSortInfo sinfo[FLEXIBLE_ARRAY_MEMBER];
+} SharedIncrementalSortInfo;
+
+/* ----------------
+ * IncrementalSortState information
+ * ----------------
+ */
+typedef struct IncrementalSortState
+{
+ ScanState ss; /* its first field is NodeTag */
+ bool bounded; /* is the result set bounded? */
+ int64 bound; /* if bounded, how many tuples are needed */
+ bool sort_Done; /* sort completed yet? */
+ bool finished; /* fetching tuples from outer node
+ is finished ? */
+ bool bounded_Done; /* value of bounded we did the sort with */
+ int64 bound_Done; /* value of bound we did the sort with */
+ void *tuplesortstate; /* private state of tuplesort.c */
+ SkipKeyData *skipKeys; /* keys, dataset is presorted by */
+ int64 groupsCount; /* number of groups with equal skip keys */
+ TupleTableSlot *sampleSlot; /* slot for sample tuple of sort group */
+ bool am_worker; /* are we a worker? */
+ SharedIncrementalSortInfo *shared_info; /* one entry per worker */
+} IncrementalSortState;
+
/* ---------------------
* GroupState information
* ---------------------
diff --git a/src/include/nodes/nodes.h b/src/include/nodes/nodes.h
index 2eb3d6d371..b6a9d6c597 100644
--- a/src/include/nodes/nodes.h
+++ b/src/include/nodes/nodes.h
@@ -73,6 +73,7 @@ typedef enum NodeTag
T_HashJoin,
T_Material,
T_Sort,
+ T_IncrementalSort,
T_Group,
T_Agg,
T_WindowAgg,
@@ -125,6 +126,7 @@ typedef enum NodeTag
T_HashJoinState,
T_MaterialState,
T_SortState,
+ T_IncrementalSortState,
T_GroupState,
T_AggState,
T_WindowAggState,
@@ -240,6 +242,7 @@ typedef enum NodeTag
T_ProjectionPath,
T_ProjectSetPath,
T_SortPath,
+ T_IncrementalSortPath,
T_GroupPath,
T_UpperUniquePath,
T_AggPath,
diff --git a/src/include/nodes/plannodes.h b/src/include/nodes/plannodes.h
index 74e9fb5f7b..033ec416fe 100644
--- a/src/include/nodes/plannodes.h
+++ b/src/include/nodes/plannodes.h
@@ -750,6 +750,17 @@ typedef struct Sort
bool *nullsFirst; /* NULLS FIRST/LAST directions */
} Sort;
+
+/* ----------------
+ * incremental sort node
+ * ----------------
+ */
+typedef struct IncrementalSort
+{
+ Sort sort;
+ int skipCols; /* number of presorted columns */
+} IncrementalSort;
+
/* ---------------
* group node -
* Used for queries with GROUP BY (but no aggregates) specified.
diff --git a/src/include/nodes/relation.h b/src/include/nodes/relation.h
index 71689b8ed6..0d072fd7c3 100644
--- a/src/include/nodes/relation.h
+++ b/src/include/nodes/relation.h
@@ -1513,6 +1513,16 @@ typedef struct SortPath
Path *subpath; /* path representing input source */
} SortPath;
+/*
+ * IncrementalSortPath
+ */
+typedef struct IncrementalSortPath
+{
+ SortPath spath;
+ int skipCols;
+} IncrementalSortPath;
+
+
/*
* GroupPath represents grouping (of presorted input)
*
diff --git a/src/include/optimizer/cost.h b/src/include/optimizer/cost.h
index d2fff76653..45cfbee724 100644
--- a/src/include/optimizer/cost.h
+++ b/src/include/optimizer/cost.h
@@ -61,6 +61,7 @@ extern bool enable_indexonlyscan;
extern bool enable_bitmapscan;
extern bool enable_tidscan;
extern bool enable_sort;
+extern bool enable_incrementalsort;
extern bool enable_hashagg;
extern bool enable_nestloop;
extern bool enable_material;
@@ -105,8 +106,9 @@ extern void cost_namedtuplestorescan(Path *path, PlannerInfo *root,
RelOptInfo *baserel, ParamPathInfo *param_info);
extern void cost_recursive_union(Path *runion, Path *nrterm, Path *rterm);
extern void cost_sort(Path *path, PlannerInfo *root,
- List *pathkeys, Cost input_cost, double tuples, int width,
- Cost comparison_cost, int sort_mem,
+ List *pathkeys, int presorted_keys,
+ Cost input_startup_cost, Cost input_total_cost,
+ double tuples, int width, Cost comparison_cost, int sort_mem,
double limit_tuples);
extern void cost_append(AppendPath *path);
extern void cost_merge_append(Path *path, PlannerInfo *root,
diff --git a/src/include/optimizer/paths.h b/src/include/optimizer/paths.h
index 0072b7aa0d..d6b8841d33 100644
--- a/src/include/optimizer/paths.h
+++ b/src/include/optimizer/paths.h
@@ -188,6 +188,7 @@ typedef enum
extern PathKeysComparison compare_pathkeys(List *keys1, List *keys2);
extern bool pathkeys_contained_in(List *keys1, List *keys2);
+extern int pathkeys_common(List *keys1, List *keys2);
extern Path *get_cheapest_path_for_pathkeys(List *paths, List *pathkeys,
Relids required_outer,
CostSelector cost_criterion,
@@ -226,6 +227,7 @@ extern List *select_outer_pathkeys_for_merge(PlannerInfo *root,
extern List *make_inner_pathkeys_for_merge(PlannerInfo *root,
List *mergeclauses,
List *outer_pathkeys);
+extern int pathkeys_useful_for_ordering(List *query_pathkeys, List *pathkeys);
extern List *truncate_useless_pathkeys(PlannerInfo *root,
RelOptInfo *rel,
List *pathkeys);
diff --git a/src/include/utils/selfuncs.h b/src/include/utils/selfuncs.h
index 299c9f846a..43e8ef20dc 100644
--- a/src/include/utils/selfuncs.h
+++ b/src/include/utils/selfuncs.h
@@ -206,6 +206,9 @@ extern void mergejoinscansel(PlannerInfo *root, Node *clause,
extern double estimate_num_groups(PlannerInfo *root, List *groupExprs,
double input_rows, List **pgset);
+extern double *estimate_pathkeys_groups(List *pathkeys, PlannerInfo *root,
+ double tuples);
+
extern void estimate_hash_bucket_stats(PlannerInfo *root,
Node *hashkey, double nbuckets,
Selectivity *mcv_freq,
diff --git a/src/include/utils/tuplesort.h b/src/include/utils/tuplesort.h
index 5d57c503ab..9a5b7f8d3c 100644
--- a/src/include/utils/tuplesort.h
+++ b/src/include/utils/tuplesort.h
@@ -90,7 +90,8 @@ extern Tuplesortstate *tuplesort_begin_heap(TupleDesc tupDesc,
int nkeys, AttrNumber *attNums,
Oid *sortOperators, Oid *sortCollations,
bool *nullsFirstFlags,
- int workMem, bool randomAccess);
+ int workMem, bool randomAccess,
+ bool skipAbbrev);
extern Tuplesortstate *tuplesort_begin_cluster(TupleDesc tupDesc,
Relation indexRel,
int workMem, bool randomAccess);
@@ -134,6 +135,8 @@ extern bool tuplesort_skiptuples(Tuplesortstate *state, int64 ntuples,
extern void tuplesort_end(Tuplesortstate *state);
+extern void tuplesort_reset(Tuplesortstate *state);
+
extern void tuplesort_get_stats(Tuplesortstate *state,
TuplesortInstrumentation *stats);
extern const char *tuplesort_method_name(TuplesortMethod m);
diff --git a/src/test/isolation/expected/drop-index-concurrently-1.out b/src/test/isolation/expected/drop-index-concurrently-1.out
index 75dff56bc4..e11fb617b5 100644
--- a/src/test/isolation/expected/drop-index-concurrently-1.out
+++ b/src/test/isolation/expected/drop-index-concurrently-1.out
@@ -19,9 +19,10 @@ Sort
step explains: EXPLAIN (COSTS OFF) EXECUTE getrow_seq;
QUERY PLAN
-Sort
+Incremental Sort
Sort Key: id, data
- -> Seq Scan on test_dc
+ Presorted Key: id
+ -> Index Scan using test_dc_pkey on test_dc
Filter: ((data)::text = '34'::text)
step select2: SELECT * FROM test_dc WHERE data=34 ORDER BY id,data;
id data
diff --git a/src/test/regress/expected/inherit.out b/src/test/regress/expected/inherit.out
index a79f891da7..0926650a0f 100644
--- a/src/test/regress/expected/inherit.out
+++ b/src/test/regress/expected/inherit.out
@@ -1517,6 +1517,7 @@ NOTICE: drop cascades to table matest1
set enable_seqscan = off;
set enable_indexscan = on;
set enable_bitmapscan = off;
+set enable_incrementalsort = off;
-- Check handling of duplicated, constant, or volatile targetlist items
explain (costs off)
SELECT thousand, tenthous FROM tenk1
@@ -1657,9 +1658,45 @@ FROM generate_series(1, 3) g(i);
{3,7,8,10,13,13,16,18,19,22}
(3 rows)
+set enable_incrementalsort = on;
+-- check incremental sort is used when enabled
+explain (costs off)
+SELECT thousand, tenthous FROM tenk1
+UNION ALL
+SELECT thousand, thousand FROM tenk1
+ORDER BY thousand, tenthous;
+ QUERY PLAN
+-------------------------------------------------------------------------
+ Merge Append
+ Sort Key: tenk1.thousand, tenk1.tenthous
+ -> Index Only Scan using tenk1_thous_tenthous on tenk1
+ -> Incremental Sort
+ Sort Key: tenk1_1.thousand, tenk1_1.thousand
+ Presorted Key: tenk1_1.thousand
+ -> Index Only Scan using tenk1_thous_tenthous on tenk1 tenk1_1
+(7 rows)
+
+explain (costs off)
+SELECT x, y FROM
+ (SELECT thousand AS x, tenthous AS y FROM tenk1 a
+ UNION ALL
+ SELECT unique2 AS x, unique2 AS y FROM tenk1 b) s
+ORDER BY x, y;
+ QUERY PLAN
+-------------------------------------------------------------
+ Merge Append
+ Sort Key: a.thousand, a.tenthous
+ -> Index Only Scan using tenk1_thous_tenthous on tenk1 a
+ -> Incremental Sort
+ Sort Key: b.unique2, b.unique2
+ Presorted Key: b.unique2
+ -> Index Only Scan using tenk1_unique2 on tenk1 b
+(7 rows)
+
reset enable_seqscan;
reset enable_indexscan;
reset enable_bitmapscan;
+reset enable_incrementalsort;
--
-- Check that constraint exclusion works correctly with partitions using
-- implicit constraints generated from the partition bound information.
diff --git a/src/test/regress/expected/sysviews.out b/src/test/regress/expected/sysviews.out
index c9c8f51e1c..898361d6b3 100644
--- a/src/test/regress/expected/sysviews.out
+++ b/src/test/regress/expected/sysviews.out
@@ -76,6 +76,7 @@ select name, setting from pg_settings where name like 'enable%';
enable_gathermerge | on
enable_hashagg | on
enable_hashjoin | on
+ enable_incrementalsort | on
enable_indexonlyscan | on
enable_indexscan | on
enable_material | on
@@ -87,7 +88,7 @@ select name, setting from pg_settings where name like 'enable%';
enable_seqscan | on
enable_sort | on
enable_tidscan | on
-(15 rows)
+(16 rows)
-- Test that the pg_timezone_names and pg_timezone_abbrevs views are
-- more-or-less working. We can't test their contents in any great detail
diff --git a/src/test/regress/sql/inherit.sql b/src/test/regress/sql/inherit.sql
index 2e42ae115d..7229997144 100644
--- a/src/test/regress/sql/inherit.sql
+++ b/src/test/regress/sql/inherit.sql
@@ -546,6 +546,7 @@ drop table matest0 cascade;
set enable_seqscan = off;
set enable_indexscan = on;
set enable_bitmapscan = off;
+set enable_incrementalsort = off;
-- Check handling of duplicated, constant, or volatile targetlist items
explain (costs off)
@@ -607,9 +608,26 @@ SELECT
ORDER BY f.i LIMIT 10)
FROM generate_series(1, 3) g(i);
+set enable_incrementalsort = on;
+
+-- check incremental sort is used when enabled
+explain (costs off)
+SELECT thousand, tenthous FROM tenk1
+UNION ALL
+SELECT thousand, thousand FROM tenk1
+ORDER BY thousand, tenthous;
+
+explain (costs off)
+SELECT x, y FROM
+ (SELECT thousand AS x, tenthous AS y FROM tenk1 a
+ UNION ALL
+ SELECT unique2 AS x, unique2 AS y FROM tenk1 b) s
+ORDER BY x, y;
+
reset enable_seqscan;
reset enable_indexscan;
reset enable_bitmapscan;
+reset enable_incrementalsort;
--
-- Check that constraint exclusion works correctly with partitions using