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MDEV-16188 Use in-memory PK filters built from range index scans

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This patch contains a full implementation of the optimization
that allows to use in-memory rowid / primary filters built for range  
conditions over indexes. In many cases usage of such filters reduce  
the number of disk seeks spent for fetching table rows.

In this implementation the choice of what possible filter to be applied  
(if any) is made purely on cost-based considerations.

This implementation re-achitectured the partial implementation of
the feature pushed by Galina Shalygina in the commit
8d5a11122c.

Besides this patch contains a better implementation of the generic  
handler function handler::multi_range_read_info_const() that
takes into account gaps between ranges when calculating the cost of
range index scans. It also contains some corrections of the
implementation of the handler function records_in_range() for MyISAM.

This patch supports the feature for InnoDB and MyISAM.
This commit is contained in:
Igor Babaev 2019-02-03 14:56:12 -08:00
commit 658128af43
190 changed files with 5644 additions and 1976 deletions
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12
mysql-test/main/subselect_no_semijoin.result
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@ -3104,13 +3104,17 @@ create table t1(a int, primary key (a));
insert into t1 values (10);
create table t2 (a int primary key, b varchar(32), c int, unique key b(c, b));
insert into t2(a, c, b) values (1,10,'359'), (2,10,'35988'), (3,10,'35989');
insert into t2(a, c, b) values (4,10,'360'), (5,10,'35998'), (6,10,'35999');
analyze table t1;
Table Op Msg_type Msg_text
test.t1 analyze status OK
explain SELECT sql_no_cache t1.a, r.a, r.b FROM t1 LEFT JOIN t2 r
ON r.a = (SELECT t2.a FROM t2 WHERE t2.c = t1.a AND t2.b <= '359899'
ORDER BY t2.c DESC, t2.b DESC LIMIT 1) WHERE t1.a = 10;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY t1 system PRIMARY NULL NULL NULL 1
1 PRIMARY r const PRIMARY PRIMARY 4 const 1
2 SUBQUERY t2 range b b 40 NULL 2 Using where
2 SUBQUERY t2 range b b 40 NULL 3 Using where
SELECT sql_no_cache t1.a, r.a, r.b FROM t1 LEFT JOIN t2 r
ON r.a = (SELECT t2.a FROM t2 WHERE t2.c = t1.a AND t2.b <= '359899'
ORDER BY t2.c DESC, t2.b DESC LIMIT 1) WHERE t1.a = 10;
@ -3122,7 +3126,7 @@ ON r.a = (SELECT t2.a FROM t2 WHERE t2.c = t1.a AND t2.b <= '359899'
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY t1 system PRIMARY NULL NULL NULL 1
1 PRIMARY r const PRIMARY PRIMARY 4 const 1
2 SUBQUERY t2 range b b 40 NULL 2 Using index condition
2 SUBQUERY t2 range b b 40 NULL 3 Using index condition
SELECT sql_no_cache t1.a, r.a, r.b FROM t1 LEFT JOIN t2 r
ON r.a = (SELECT t2.a FROM t2 WHERE t2.c = t1.a AND t2.b <= '359899'
ORDER BY t2.c, t2.b LIMIT 1) WHERE t1.a = 10;
@ -3707,7 +3711,7 @@ ORDER BY t1.t DESC LIMIT 1);
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY t2 system NULL NULL NULL NULL 1
1 PRIMARY t1 index NULL PRIMARY 13 NULL 11 Using where; Using index
2 SUBQUERY t1 range PRIMARY PRIMARY 13 NULL 5 Using where; Using index
2 SUBQUERY t1 range PRIMARY PRIMARY 13 NULL 6 Using where; Using index
SELECT * FROM t1,t2
WHERE t1.t = (SELECT t1.t FROM t1
WHERE t1.t < t2.t AND t1.i2=1 AND t2.i1=t1.i1
@ -4973,7 +4977,7 @@ UNIQUE KEY b (b,c),
KEY c (c),
KEY b_2 (b)
);
INSERT INTO t3 VALUES (1,1,1), (2,32,1);
INSERT INTO t3 VALUES (1,1,1), (2,32,1), (3,33,1), (4,34,2);
explain
SELECT t1.a, (SELECT 1 FROM t2 WHERE t2.b=t3.c AND t2.c=t1.a ORDER BY t2.d LIMIT 1) AS incorrect FROM t1, t3 WHERE t3.b=t1.a;
id select_type table type possible_keys key key_len ref rows Extra