Disable materializing strategy of the planner in look-a-like tests.

It is just because of difference in behaviour of different versions of PGPro executor. In some versions it can disable unnecessary repeatable scans of a materialize node. XXX: Could we solve a problem by improvement of AQO logic?

Author: danolivo

expected/look_a_like.out

@@ -2,6 +2,7 @@ CREATE EXTENSION aqo;
 SET aqo.join_threshold = 0;
 SET aqo.mode = 'learn';
 SET aqo.show_details = 'on';
+SET enable_material = 'off';
 DROP TABLE IF EXISTS a,b CASCADE;
 NOTICE: table "a" does not exist, skipping
 NOTICE: table "b" does not exist, skipping
@@ -38,65 +39,60 @@ WHERE str NOT LIKE 'Query Identifier%';
 JOINS: 0
 (8 rows)
 
--- cardinality 100 in the first Seq Scan on a
 SELECT str AS result
 FROM expln('
 SELECT x FROM A,B WHERE x = 5 AND A.x = B.y;') AS str
-WHERE str NOT LIKE 'Query Identifier%';
-result
-------------------------------------------------------------
+WHERE str NOT LIKE 'Query Identifier%'
+; -- Find cardinality for SCAN A(x=5) from a neigur class, created by the
+result
+--------------------------------------------------------
 Nested Loop (actual rows=10000 loops=1)
 AQO not used
 Output: a.x
--> Seq Scan on public.a (actual rows=100 loops=1)
+-> Seq Scan on public.b (actual rows=100 loops=1)
+AQO not used
+Output: b.y
+Filter: (b.y = 5)
+Rows Removed by Filter: 900
+-> Seq Scan on public.a (actual rows=100 loops=100)
 AQO: rows=100, error=0%
 Output: a.x
 Filter: (a.x = 5)
 Rows Removed by Filter: 900
--> Materialize (actual rows=100 loops=100)
-AQO not used
-Output: b.y
--> Seq Scan on public.b (actual rows=100 loops=1)
-AQO not used
-Output: b.y
-Filter: (b.y = 5)
-Rows Removed by Filter: 900
 Using aqo: true
 AQO mode: LEARN
 JOINS: 0
-(19 rows)
+(16 rows)
 
--- cardinality 100 in Nesteed Loop in the first Seq Scan on a
+-- query, executed above.
 SELECT str AS result
 FROM expln('
 SELECT x, sum(x) FROM A,B WHERE y = 5 AND A.x = B.y group by(x);') AS str
-WHERE str NOT LIKE 'Query Identifier%';
-result
-------------------------------------------------------------------
+WHERE str NOT LIKE 'Query Identifier%'
+; -- Find the JOIN cardinality from a neigur class.
+result
+--------------------------------------------------------------
 GroupAggregate (actual rows=1 loops=1)
 AQO not used
 Output: a.x, sum(a.x)
 Group Key: a.x
 -> Nested Loop (actual rows=10000 loops=1)
-AQO not used
+AQO: rows=10000, error=0%
 Output: a.x
 -> Seq Scan on public.a (actual rows=100 loops=1)
 AQO: rows=100, error=0%
 Output: a.x
 Filter: (a.x = 5)
 Rows Removed by Filter: 900
--> Materialize (actual rows=100 loops=100)
+-> Seq Scan on public.b (actual rows=100 loops=100)
 AQO: rows=100, error=0%
 Output: b.y
--> Seq Scan on public.b (actual rows=100 loops=1)
-AQO: rows=100, error=0%
-Output: b.y
-Filter: (b.y = 5)
-Rows Removed by Filter: 900
+Filter: (b.y = 5)
+Rows Removed by Filter: 900
 Using aqo: true
 AQO mode: LEARN
 JOINS: 1
-(23 rows)
+(20 rows)
 
 -- cardinality 100 in the first Seq Scan on a
 SELECT str AS result
@@ -176,37 +172,38 @@ SELECT str AS result
 FROM expln('
 SELECT x FROM A,B where x < 10 and y > 10 group by(x);') AS str
 WHERE str NOT LIKE 'Query Identifier%' and str NOT LIKE '%Memory%';
-result
-----------------------------------------------------------------
+result
+----------------------------------------------------------
 HashAggregate (actual rows=0 loops=1)
 AQO not used
 Output: a.x
 Group Key: a.x
 -> Nested Loop (actual rows=0 loops=1)
 AQO not used
 Output: a.x
--> Seq Scan on public.a (actual rows=1000 loops=1)
-AQO: rows=1000, error=0%
+-> Seq Scan on public.b (actual rows=0 loops=1)
+AQO not used
+Output: b.y
+Filter: (b.y > 10)
+Rows Removed by Filter: 1000
+-> Seq Scan on public.a (never executed)
+AQO: rows=1000
 Output: a.x
 Filter: (a.x < 10)
--> Materialize (actual rows=0 loops=1000)
-AQO not used
--> Seq Scan on public.b (actual rows=0 loops=1)
-AQO not used
-Filter: (b.y > 10)
-Rows Removed by Filter: 1000
 Using aqo: true
 AQO mode: LEARN
 JOINS: 1
-(20 rows)
+(19 rows)
 
--- cardinality 1000 Hash Cond: (a.x = b.y) and 1 Seq Scan on b
--- this cardinality is wrong because we take it from bad neibours (previous query).
--- clause y > 10 give count of rows with the same clauses.
+--
+-- TODO:
+-- Not executed case. What could we do better here?
+--
 SELECT str AS result
 FROM expln('
 SELECT x,y FROM A,B WHERE x < 10 and y > 10 AND A.x = B.y;') AS str
-WHERE str NOT LIKE 'Query Identifier%' and str NOT LIKE '%Memory%';
+WHERE str NOT LIKE 'Query Identifier%' and str NOT LIKE '%Memory%'
+;
 result
 ----------------------------------------------------------
 Hash Join (actual rows=0 loops=1)
@@ -230,6 +227,7 @@ WHERE str NOT LIKE 'Query Identifier%' and str NOT LIKE '%Memory%';
 JOINS: 0
 (19 rows)
 
+RESET enable_material;
 DROP TABLE a,b CASCADE;
 SELECT true FROM aqo_reset();
 ?column?

sql/look_a_like.sql

@@ -3,6 +3,8 @@ SET aqo.join_threshold = 0;
 SET aqo.mode = 'learn';
 SET aqo.show_details = 'on';
 
+SET enable_material = 'off';
+
 DROP TABLE IF EXISTS a,b CASCADE;
 CREATE TABLE a (x int);
 INSERT INTO a (x) SELECT mod(ival,10) FROM generate_series(1,1000) As ival;
@@ -28,16 +30,20 @@ SELECT str AS result
 FROM expln('
 SELECT x FROM A where x = 5;') AS str
 WHERE str NOT LIKE 'Query Identifier%';
--- cardinality 100 in the first Seq Scan on a
+
 SELECT str AS result
 FROM expln('
 SELECT x FROM A,B WHERE x = 5 AND A.x = B.y;') AS str
-WHERE str NOT LIKE 'Query Identifier%';
--- cardinality 100 in Nesteed Loop in the first Seq Scan on a
+WHERE str NOT LIKE 'Query Identifier%'
+; -- Find cardinality for SCAN A(x=5) from a neigur class, created by the
+-- query, executed above.
+
 SELECT str AS result
 FROM expln('
 SELECT x, sum(x) FROM A,B WHERE y = 5 AND A.x = B.y group by(x);') AS str
-WHERE str NOT LIKE 'Query Identifier%';
+WHERE str NOT LIKE 'Query Identifier%'
+; -- Find the JOIN cardinality from a neigur class.
+
 -- cardinality 100 in the first Seq Scan on a
 SELECT str AS result
 FROM expln('
@@ -61,14 +67,18 @@ SELECT str AS result
 FROM expln('
 SELECT x FROM A,B where x < 10 and y > 10 group by(x);') AS str
 WHERE str NOT LIKE 'Query Identifier%' and str NOT LIKE '%Memory%';
--- cardinality 1000 Hash Cond: (a.x = b.y) and 1 Seq Scan on b
--- this cardinality is wrong because we take it from bad neibours (previous query).
--- clause y > 10 give count of rows with the same clauses.
+
+--
+-- TODO:
+-- Not executed case. What could we do better here?
+--
 SELECT str AS result
 FROM expln('
 SELECT x,y FROM A,B WHERE x < 10 and y > 10 AND A.x = B.y;') AS str
-WHERE str NOT LIKE 'Query Identifier%' and str NOT LIKE '%Memory%';
+WHERE str NOT LIKE 'Query Identifier%' and str NOT LIKE '%Memory%'
+;
 
+RESET enable_material;
 DROP TABLE a,b CASCADE;
 SELECT true FROM aqo_reset();
-DROP EXTENSION aqo CASCADE;
+DROP EXTENSION aqo CASCADE;