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danolivodanolivo
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Bugfix. inherent number of rows from parallel path , not from RelOptInfo.
1 parent 11be868 commit 91ab602

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3 files changed

+104
-13
lines changed

3 files changed

+104
-13
lines changed

‎contrib/tempscan/expected/basic.out

Lines changed: 79 additions & 6 deletions
Original file line numberDiff line numberDiff line change
@@ -31,14 +31,87 @@ SELECT count(*) FROM parallel_test;
3131
-- Should also utilise parallel workers like scanning of a plain table
3232
EXPLAIN (COSTS OFF)
3333
SELECT count(*) FROM parallel_test_tmp;
34-
QUERY PLAN
35-
----------------------------------------------------------
36-
Aggregate
34+
QUERY PLAN
35+
----------------------------------------------------------------
36+
Finalize Aggregate
3737
-> Gather
3838
Workers Planned: 1
39-
-> Custom Scan (nodeCustomTempScan)
40-
-> Parallel Seq Scan on parallel_test_tmp
41-
(5 rows)
39+
-> Partial Aggregate
40+
-> Custom Scan (nodeCustomTempScan)
41+
-> Parallel Seq Scan on parallel_test_tmp
42+
(6 rows)
43+
44+
-- Want to see here partial aggregate over parallel join
45+
EXPLAIN (COSTS OFF)
46+
SELECT count(*) FROM parallel_test t1 NATURAL JOIN parallel_test t2;
47+
QUERY PLAN
48+
---------------------------------------------------------------------
49+
Finalize Aggregate
50+
-> Gather
51+
Workers Planned: 1
52+
-> Partial Aggregate
53+
-> Parallel Hash Join
54+
Hash Cond: (t1.x = t2.x)
55+
-> Parallel Seq Scan on parallel_test t1
56+
-> Parallel Hash
57+
-> Parallel Seq Scan on parallel_test t2
58+
(9 rows)
59+
60+
EXPLAIN (COSTS OFF)
61+
SELECT count(*) FROM parallel_test_tmp t1 NATURAL JOIN parallel_test t2;
62+
QUERY PLAN
63+
-------------------------------------------------------------------------
64+
Finalize Aggregate
65+
-> Gather
66+
Workers Planned: 1
67+
-> Partial Aggregate
68+
-> Parallel Hash Join
69+
Hash Cond: (t1.x = t2.x)
70+
-> Custom Scan (nodeCustomTempScan)
71+
-> Parallel Seq Scan on parallel_test_tmp t1
72+
-> Parallel Hash
73+
-> Parallel Seq Scan on parallel_test t2
74+
(10 rows)
75+
76+
-- Just see how merge join manages custom parallel scan path
77+
SET enable_hashjoin = 'off';
78+
EXPLAIN (COSTS OFF)
79+
SELECT count(*) FROM parallel_test t1 NATURAL JOIN parallel_test t2;
80+
QUERY PLAN
81+
---------------------------------------------------------------------
82+
Finalize Aggregate
83+
-> Gather
84+
Workers Planned: 1
85+
-> Partial Aggregate
86+
-> Merge Join
87+
Merge Cond: (t1.x = t2.x)
88+
-> Sort
89+
Sort Key: t1.x
90+
-> Parallel Seq Scan on parallel_test t1
91+
-> Sort
92+
Sort Key: t2.x
93+
-> Seq Scan on parallel_test t2
94+
(12 rows)
95+
96+
EXPLAIN (COSTS OFF)
97+
SELECT count(*) FROM parallel_test_tmp t1 NATURAL JOIN parallel_test t2;
98+
QUERY PLAN
99+
-------------------------------------------------------------------------------
100+
Finalize Aggregate
101+
-> Gather
102+
Workers Planned: 1
103+
-> Partial Aggregate
104+
-> Merge Join
105+
Merge Cond: (t1.x = t2.x)
106+
-> Sort
107+
Sort Key: t1.x
108+
-> Custom Scan (nodeCustomTempScan)
109+
-> Parallel Seq Scan on parallel_test_tmp t1
110+
-> Sort
111+
Sort Key: t2.x
112+
-> Seq Scan on parallel_test t2
113+
(13 rows)
42114

115+
RESET enable_hashjoin;
43116
RESET tempscan.enable;
44117
DROP TABLE parallel_test, parallel_test_tmp;

‎contrib/tempscan/nodeCustomTempScan.c

Lines changed: 11 additions & 7 deletions
Original file line numberDiff line numberDiff line change
@@ -14,6 +14,7 @@
1414
#include "postgres.h"
1515

1616
#include "nodes/extensible.h"
17+
#include "optimizer/clauses.h"
1718
#include "optimizer/cost.h"
1819
#include "optimizer/pathnode.h"
1920
#include "optimizer/paths.h"
@@ -70,6 +71,7 @@ static CustomExecMethods exec_methods =
7071
};
7172

7273
static set_rel_pathlist_hook_type set_rel_pathlist_hook_next = NULL;
74+
7375
static bool tempscan_enable = false;
7476

7577
void _PG_init(void);
@@ -90,7 +92,7 @@ create_partial_tempscan_path(PlannerInfo *root, RelOptInfo *rel,
9092
pathnode->pathtype = T_CustomScan;
9193
pathnode->parent = rel;
9294
pathnode->pathtarget = rel->reltarget;
93-
pathnode->rows = rel->rows;
95+
pathnode->rows = path->rows; /* Don't use rel->rows! Remember semantics of this field in the parallel case */
9496

9597
/* XXX: Just for now */
9698
pathnode->param_info = NULL;
@@ -100,8 +102,8 @@ create_partial_tempscan_path(PlannerInfo *root, RelOptInfo *rel,
100102
pathnode->parallel_workers = path->parallel_workers;
101103

102104
/* DEBUGGING purposes only */
103-
pathnode->startup_cost = path->startup_cost / disable_cost;
104-
pathnode->total_cost = path->total_cost / disable_cost;
105+
pathnode->startup_cost = path->startup_cost /*/ disable_cost*/;
106+
pathnode->total_cost = path->total_cost /*/ disable_cost*/;
105107

106108
cpath->custom_paths = list_make1(path);
107109
cpath->custom_private = NIL;
@@ -213,21 +215,25 @@ try_partial_tempscan(PlannerInfo *root, RelOptInfo *rel, Index rti,
213215
if (set_rel_pathlist_hook_next)
214216
(*set_rel_pathlist_hook_next)(root, rel, rti, rte);
215217

216-
if (rel->consider_parallel)
218+
if (!tempscan_enable || rel->consider_parallel)
217219
return;
218220

219221
if (rte->rtekind != RTE_RELATION ||
220222
get_rel_persistence(rte->relid) != RELPERSISTENCE_TEMP)
221223
return;
222224

225+
/* HACK */
226+
if (!is_parallel_safe(root, (Node *) rel->baserestrictinfo) ||
227+
!is_parallel_safe(root, (Node *) rel->reltarget->exprs))
228+
return;
229+
223230
parallel_workers = compute_parallel_worker(rel, rel->pages, -1,
224231
max_parallel_workers_per_gather);
225232

226233
/* If any limit was set to zero, the user doesn't want a parallel scan. */
227234
if (parallel_workers <= 0)
228235
return;
229236

230-
/* HACK */
231237
rel->consider_parallel = true;
232238

233239
path = create_seqscan_path(root, rel, NULL, parallel_workers);
@@ -238,8 +244,6 @@ try_partial_tempscan(PlannerInfo *root, RelOptInfo *rel, Index rti,
238244
create_partial_tempscan_path(root, rel, path));
239245
}
240246

241-
if (!bms_equal(rel->relids, root->all_query_rels))
242-
rel->consider_parallel = false;
243247
Assert(IsA(linitial(rel->partial_pathlist), CustomPath));
244248
}
245249

‎contrib/tempscan/sql/basic.sql

Lines changed: 14 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -29,5 +29,19 @@ SELECT count(*) FROM parallel_test;
2929
EXPLAIN (COSTS OFF)
3030
SELECT count(*) FROM parallel_test_tmp;
3131

32+
-- Want to see here partial aggregate over parallel join
33+
EXPLAIN (COSTS OFF)
34+
SELECT count(*) FROM parallel_test t1 NATURAL JOIN parallel_test t2;
35+
EXPLAIN (COSTS OFF)
36+
SELECT count(*) FROM parallel_test_tmp t1 NATURAL JOIN parallel_test t2;
37+
38+
-- Just see how merge join manages custom parallel scan path
39+
SET enable_hashjoin = 'off';
40+
EXPLAIN (COSTS OFF)
41+
SELECT count(*) FROM parallel_test t1 NATURAL JOIN parallel_test t2;
42+
EXPLAIN (COSTS OFF)
43+
SELECT count(*) FROM parallel_test_tmp t1 NATURAL JOIN parallel_test t2;
44+
45+
RESET enable_hashjoin;
3246
RESET tempscan.enable;
3347
DROP TABLE parallel_test, parallel_test_tmp;

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