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danolivoAlena0704
danolivo
authored and
Alena0704
committed
Fix the bug with serialization machinery.
Change the AQO plan node behaviour: now we add such node also in the case when forced stat gathering option is enabled even in disabled mode. Also: 1. Do not add AQO info into an explain AQO sentence if AQO node isn't existed for the node. 2. Exclude node which aren't predicted by AQO from a cardinality error computation. Introduce 'parallel_workers' regression test.
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9 files changed

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-84
lines changed

9 files changed

+236
-84
lines changed

‎Makefile‎

Lines changed: 2 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -23,6 +23,7 @@ REGRESS = aqo_disabled \
2323
forced_stat_collection \
2424
unsupported \
2525
clean_aqo_data \
26+
parallel_workers \
2627
plancache \
2728
statement_timeout \
2829
temp_tables \
@@ -49,4 +50,4 @@ subdir = contrib/aqo
4950
top_builddir = ../..
5051
include $(top_builddir)/src/Makefile.global
5152
include $(top_srcdir)/contrib/contrib-global.mk
52-
endif
53+
endif

‎expected/feature_subspace.out‎

Lines changed: 2 additions & 5 deletions
Original file line numberDiff line numberDiff line change
@@ -29,19 +29,17 @@ WHERE str NOT LIKE '%Memory%';
2929
AQO not used
3030
Merge Cond: (a.x = b.x)
3131
-> Sort (actual rows=10 loops=1)
32-
AQO not used
3332
Sort Key: a.x
3433
-> Seq Scan on a (actual rows=10 loops=1)
3534
AQO not used
3635
-> Sort (actual rows=11 loops=1)
37-
AQO not used
3836
Sort Key: b.x
3937
-> Seq Scan on b (actual rows=100 loops=1)
4038
AQO not used
4139
Using aqo: true
4240
AQO mode: LEARN
4341
JOINS: 0
44-
(16 rows)
42+
(14 rows)
4543

4644
-- TODO: Using method of other classes neighbours we get a bad estimation.
4745
SELECT str AS result
@@ -56,13 +54,12 @@ WHERE str NOT LIKE '%Memory%';
5654
-> Seq Scan on b (actual rows=100 loops=1)
5755
AQO: rows=100, error=0%
5856
-> Hash (actual rows=10 loops=1)
59-
AQO not used
6057
-> Seq Scan on a (actual rows=10 loops=1)
6158
AQO: rows=10, error=0%
6259
Using aqo: true
6360
AQO mode: LEARN
6461
JOINS: 0
65-
(12 rows)
62+
(11 rows)
6663

6764
-- Look into the reason: two JOINs from different classes have the same FSS.
6865
SELECT to_char(d1.targets[1], 'FM999.00') AS target FROM aqo_data d1

‎expected/look_a_like.out‎

Lines changed: 2 additions & 5 deletions
Original file line numberDiff line numberDiff line change
@@ -148,15 +148,13 @@ WHERE str NOT LIKE 'Query Identifier%' and str NOT LIKE '%Memory%';
148148
Output: a.x, b.y
149149
Merge Cond: (a.x = b.y)
150150
-> Sort (actual rows=1000 loops=1)
151-
AQO not used
152151
Output: a.x
153152
Sort Key: a.x
154153
-> Seq Scan on public.a (actual rows=1000 loops=1)
155154
AQO: rows=1000, error=0%
156155
Output: a.x
157156
Filter: (a.x < 10)
158157
-> Sort (actual rows=99901 loops=1)
159-
AQO not used
160158
Output: b.y
161159
Sort Key: b.y
162160
-> Seq Scan on public.b (actual rows=1000 loops=1)
@@ -165,7 +163,7 @@ WHERE str NOT LIKE 'Query Identifier%' and str NOT LIKE '%Memory%';
165163
Using aqo: true
166164
AQO mode: LEARN
167165
JOINS: 0
168-
(22 rows)
166+
(20 rows)
169167

170168
-- cardinality 100 in Seq Scan on a and Seq Scan on b
171169
SELECT str AS result
@@ -215,7 +213,6 @@ WHERE str NOT LIKE 'Query Identifier%' and str NOT LIKE '%Memory%'
215213
Output: a.x
216214
Filter: (a.x < 10)
217215
-> Hash (actual rows=0 loops=1)
218-
AQO not used
219216
Output: b.y
220217
-> Seq Scan on public.b (actual rows=0 loops=1)
221218
AQO: rows=1, error=100%
@@ -225,7 +222,7 @@ WHERE str NOT LIKE 'Query Identifier%' and str NOT LIKE '%Memory%'
225222
Using aqo: true
226223
AQO mode: LEARN
227224
JOINS: 0
228-
(19 rows)
225+
(18 rows)
229226

230227
RESET enable_material;
231228
DROP TABLE a,b CASCADE;

‎expected/parallel_workers.out‎

Lines changed: 125 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,125 @@
1+
-- Specifically test AQO machinery for queries uses partial paths and executed
2+
-- with parallel workers.
3+
CREATE EXTENSION aqo;
4+
-- Utility tool. Allow to filter system-dependent strings from explain output.
5+
CREATE OR REPLACE FUNCTION expln(query_string text) RETURNS SETOF text AS $$
6+
BEGIN
7+
RETURN QUERY
8+
EXECUTE format('%s', query_string);
9+
RETURN;
10+
END;
11+
$$ LANGUAGE PLPGSQL;
12+
SET aqo.join_threshold = 0;
13+
SET aqo.mode = 'learn';
14+
SET aqo.show_details = true;
15+
-- Be generous with a number parallel workers to test the machinery
16+
SET max_parallel_workers = 64;
17+
SET max_parallel_workers_per_gather = 64;
18+
-- Enforce usage of parallel workers
19+
SET parallel_setup_cost = 0.1;
20+
SET parallel_tuple_cost = 0.0001;
21+
CREATE TABLE t AS (
22+
SELECT x AS id, repeat('a', 512) AS payload FROM generate_series(1, 1E5) AS x
23+
);
24+
ANALYZE t;
25+
-- Simple test. Check serialization machinery mostly.
26+
SELECT count(*) FROM t WHERE id % 100 = 0; -- Learning stage
27+
count
28+
-------
29+
1000
30+
(1 row)
31+
32+
SELECT str FROM expln('
33+
EXPLAIN (ANALYZE, COSTS OFF, TIMING OFF, SUMMARY OFF)
34+
SELECT count(*) FROM t WHERE id % 100 = 0;') AS str
35+
WHERE str NOT LIKE '%Worker%';
36+
str
37+
--------------------------------------------------------------------
38+
Finalize Aggregate (actual rows=1 loops=1)
39+
AQO not used
40+
-> Gather (actual rows=3 loops=1)
41+
AQO not used
42+
-> Partial Aggregate (actual rows=1 loops=3)
43+
AQO not used
44+
-> Parallel Seq Scan on t (actual rows=333 loops=3)
45+
AQO: rows=1000, error=0%
46+
Filter: ((id % '100'::numeric) = '0'::numeric)
47+
Rows Removed by Filter: 33000
48+
Using aqo: true
49+
AQO mode: LEARN
50+
JOINS: 0
51+
(13 rows)
52+
53+
-- More complex query just to provoke errors
54+
SELECT count(*) FROM
55+
(SELECT id FROM t WHERE id % 100 = 0 GROUP BY (id)) AS q1,
56+
(SELECT max(id) AS id, payload FROM t
57+
WHERE id % 101 = 0 GROUP BY (payload)) AS q2
58+
WHERE q1.id = q2.id; -- Learning stage
59+
count
60+
-------
61+
0
62+
(1 row)
63+
64+
-- XXX: Why grouping prediction isn't working here?
65+
SELECT str FROM expln('
66+
EXPLAIN (ANALYZE, COSTS OFF, TIMING OFF, SUMMARY OFF)
67+
SELECT count(*) FROM
68+
(SELECT id FROM t WHERE id % 100 = 0 GROUP BY (id)) AS q1,
69+
(SELECT max(id) AS id, payload FROM t
70+
WHERE id % 101 = 0 GROUP BY (payload)) AS q2
71+
WHERE q1.id = q2.id;') AS str
72+
WHERE str NOT LIKE '%Workers%' AND str NOT LIKE '%Sort Method%';
73+
str
74+
--------------------------------------------------------------------------------------------------
75+
Aggregate (actual rows=1 loops=1)
76+
AQO not used
77+
-> Merge Join (actual rows=0 loops=1)
78+
AQO not used
79+
Merge Cond: (q2.id = t_1.id)
80+
-> Sort (actual rows=1 loops=1)
81+
Sort Key: q2.id
82+
-> Subquery Scan on q2 (actual rows=1 loops=1)
83+
AQO not used
84+
-> Finalize GroupAggregate (actual rows=1 loops=1)
85+
AQO not used
86+
Group Key: t.payload
87+
-> Gather Merge (actual rows=3 loops=1)
88+
AQO not used
89+
-> Partial GroupAggregate (actual rows=1 loops=3)
90+
AQO not used
91+
Group Key: t.payload
92+
-> Sort (actual rows=330 loops=3)
93+
AQO not used
94+
Sort Key: t.payload
95+
-> Parallel Seq Scan on t (actual rows=330 loops=3)
96+
AQO: rows=991, error=0%
97+
Filter: ((id % '101'::numeric) = '0'::numeric)
98+
Rows Removed by Filter: 33003
99+
-> Group (actual rows=1000 loops=1)
100+
AQO not used
101+
Group Key: t_1.id
102+
-> Gather Merge (actual rows=1000 loops=1)
103+
AQO not used
104+
-> Group (actual rows=333 loops=3)
105+
AQO not used
106+
Group Key: t_1.id
107+
-> Sort (actual rows=333 loops=3)
108+
AQO not used
109+
Sort Key: t_1.id
110+
-> Parallel Seq Scan on t t_1 (actual rows=333 loops=3)
111+
AQO: rows=991, error=-1%
112+
Filter: ((id % '100'::numeric) = '0'::numeric)
113+
Rows Removed by Filter: 33000
114+
Using aqo: true
115+
AQO mode: LEARN
116+
JOINS: 1
117+
(42 rows)
118+
119+
RESET parallel_tuple_cost;
120+
RESET parallel_setup_cost;
121+
RESET max_parallel_workers;
122+
RESET max_parallel_workers_per_gather;
123+
DROP TABLE t;
124+
DROP FUNCTION expln;
125+
DROP EXTENSION aqo;

‎expected/unsupported.out‎

Lines changed: 3 additions & 5 deletions
Original file line numberDiff line numberDiff line change
@@ -375,7 +375,6 @@ SELECT count(*) FROM
375375
Filter: (x <> t_1.x)
376376
Rows Removed by Filter: 50
377377
-> Hash (actual rows=851 loops=1)
378-
AQO not used
379378
-> Seq Scan on t (actual rows=851 loops=1)
380379
AQO: rows=851, error=0%
381380
Filter: (((x % 3))::numeric < (SubPlan 1))
@@ -390,7 +389,7 @@ SELECT count(*) FROM
390389
Using aqo: true
391390
AQO mode: LEARN
392391
JOINS: 1
393-
(31 rows)
392+
(30 rows)
394393

395394
-- Two identical subplans in a clause
396395
EXPLAIN (ANALYZE, COSTS OFF, SUMMARY OFF, TIMING OFF)
@@ -543,12 +542,11 @@ WHERE str NOT LIKE '%Heap Blocks%' AND str NOT LIKE '%Query Identifier%';
543542
Filter: (t.x < 3)
544543
Rows Removed by Filter: 300
545544
-> Bitmap Index Scan on ind2 (actual rows=350 loops=1)
546-
AQO not used
547545
Index Cond: (mod(t.x, 3) = 1)
548546
Using aqo: true
549547
AQO mode: LEARN
550548
JOINS: 0
551-
(14 rows)
549+
(13 rows)
552550

553551
-- Best choice is ...
554552
ANALYZE t;
@@ -577,7 +575,7 @@ ORDER BY (md5(query_text),error) DESC;
577575
-------+------------------------------------------------------------------------------------------------
578576
0.768 | SELECT count(*) FROM (SELECT count(*) FROM t1 GROUP BY (x,y)) AS q1;
579577
0.070 | SELECT count(*) FROM (SELECT * FROM t GROUP BY (x) HAVING x > 3) AS q1;
580-
1.416 | SELECT count(*) FROM t WHERE x < 3 AND mod(x,3) = 1;
578+
0.000 | SELECT count(*) FROM t WHERE x < 3 AND mod(x,3) = 1;
581579
0.000 | SELECT * FROM +
582580
| (SELECT * FROM t WHERE x < 0) AS t0 +
583581
| JOIN +

‎path_utils.c‎

Lines changed: 20 additions & 16 deletions
Original file line numberDiff line numberDiff line change
@@ -63,9 +63,7 @@ create_aqo_plan_node()
6363

6464
/*
6565
* Extract an AQO node from the plan private field.
66-
* If no one node was found, return pointer to the default value or allocate new
67-
* node (with default value) according to 'create' field.
68-
* Can't return NULL value at all.
66+
* If no one node was found, return pointer to the default value or return NULL.
6967
*/
7068
AQOPlanNode *
7169
get_aqo_plan_node(Plan *plan, bool create)
@@ -90,7 +88,7 @@ get_aqo_plan_node(Plan *plan, bool create)
9088
if (node == NULL)
9189
{
9290
if (!create)
93-
return &DefaultAQOPlanNode;
91+
return NULL;
9492

9593
node = create_aqo_plan_node();
9694
plan->ext_nodes = lappend(plan->ext_nodes, node);
@@ -481,9 +479,14 @@ is_appropriate_path(Path *path)
481479
}
482480

483481
/*
484-
* Converts path info into plan node for collecting it after query execution.
482+
* Add AQO data into the plan node, if necessary.
483+
*
484+
* The necesssary case is when AQO is learning on this query, used for a
485+
* prediction (and we will need the data to show prediction error at the end) or
486+
* just to gather a plan statistics.
485487
* Don't switch here to any AQO-specific memory contexts, because we should
486-
* store AQO prediction in the same context, as the plan.
488+
* store AQO prediction in the same context, as the plan. So, explicitly free
489+
* all unneeded data.
487490
*/
488491
void
489492
aqo_create_plan_hook(PlannerInfo *root, Path *src, Plan **dest)
@@ -495,7 +498,8 @@ aqo_create_plan_hook(PlannerInfo *root, Path *src, Plan **dest)
495498
if (prev_create_plan_hook)
496499
prev_create_plan_hook(root, src, dest);
497500

498-
if (!query_context.use_aqo && !query_context.learn_aqo)
501+
if (!query_context.use_aqo && !query_context.learn_aqo &&
502+
!query_context.collect_stat)
499503
return;
500504

501505
is_join_path = (src->type == T_NestPath || src->type == T_MergePath ||
@@ -552,6 +556,11 @@ aqo_create_plan_hook(PlannerInfo *root, Path *src, Plan **dest)
552556
}
553557
else
554558
{
559+
/*
560+
* In the case of forced stat gathering AQO must store fss as well as
561+
* parallel divisor. Negative predicted cardinality field will be a sign
562+
* that it is not a prediction, just statistics.
563+
*/
555564
node->prediction = src->parent->predicted_cardinality;
556565
node->fss = src->parent->fss_hash;
557566
}
@@ -624,11 +633,6 @@ AQOnodeOut(struct StringInfoData *str, const struct ExtensibleNode *enode)
624633
{
625634
AQOPlanNode *node = (AQOPlanNode *) enode;
626635

627-
node->had_path = false;
628-
node->jointype = 0;
629-
node->parallel_divisor = 1.0;
630-
node->was_parametrized = false;
631-
632636
/* For Adaptive optimization DEBUG purposes */
633637
WRITE_INT_FIELD(fss);
634638
WRITE_FLOAT_FIELD(prediction, "%.0f");
@@ -676,10 +680,10 @@ AQOnodeRead(struct ExtensibleNode *enode)
676680
const char *token;
677681
int length;
678682

679-
READ_BOOL_FIELD(had_path);
680-
READ_ENUM_FIELD(jointype, JoinType);
681-
READ_FLOAT_FIELD(parallel_divisor);
682-
READ_BOOL_FIELD(was_parametrized);
683+
local_node->had_path = false;
684+
local_node->jointype = 0;
685+
local_node->parallel_divisor = 1.0;
686+
local_node->was_parametrized = false;
683687

684688
local_node->rels = palloc0(sizeof(RelSortOut));
685689
local_node->clauses = NIL;

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