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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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22
mysql-test/main/subselect_sj_jcl6.result
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@ -217,7 +217,7 @@ a b a b
insert into t1 select (A.a + 10 * B.a),1 from t0 A, t0 B;
explain extended select * from t1 where a in (select pk from t10 where pk<3);
id select_type table type possible_keys key key_len ref rows filtered Extra
1 PRIMARY t10 range PRIMARY PRIMARY 4 NULL 4 100.00 Using where; Using index
1 PRIMARY t10 range PRIMARY PRIMARY 4 NULL 3 100.00 Using where; Using index
1 PRIMARY t1 ALL NULL NULL NULL NULL 103 100.00 Using where; Using join buffer (flat, BNL join)
Warnings:
Note 1003 select `test`.`t1`.`a` AS `a`,`test`.`t1`.`b` AS `b` from `test`.`t10` join `test`.`t1` where `test`.`t1`.`a` = `test`.`t10`.`pk` and `test`.`t10`.`pk` < 3
@ -742,7 +742,7 @@ SELECT int_key FROM ot1
WHERE int_nokey IN (SELECT it2.int_key
FROM it1 LEFT JOIN it2 ON it2.datetime_key);
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY <subquery2> ALL distinct_key NULL NULL NULL 11
1 PRIMARY <subquery2> ALL distinct_key NULL NULL NULL 10
1 PRIMARY ot1 ALL NULL NULL NULL NULL 20 Using where; Using join buffer (flat, BNL join)
2 MATERIALIZED it1 index NULL int_key 4 NULL 2 Using index
2 MATERIALIZED it2 ALL int_key,datetime_key NULL NULL NULL 20 Using where; Using join buffer (flat, BNL join)
@ -3093,9 +3093,11 @@ set optimizer_switch= @tmp_mdev6859;
set @tmp_mdev12675=@@optimizer_switch;
set optimizer_switch=default;
create table t1 (a int) engine=myisam;
insert into t1 values (5),(3),(2),(7),(2),(5),(1);
insert into t1 values (3),(2),(7),(2),(1);
create table t2 (b int, index idx(b)) engine=myisam;
insert into t2 values (2),(3),(2),(1),(3),(4);
insert into t2 values (2),(3),(2),(1),(3),(4),(1),(2),(1),(2);
insert into t2 select b+10 from t2;
insert into t2 select b+10 from t2;
insert into t2 select b+10 from t2;
insert into t2 select b+10 from t2;
insert into t2 select b+10 from t2;
@ -3114,15 +3116,15 @@ test.t2 analyze status OK
explain
select a from t1, t2 where b between 1 and 2 and a in (select b from t2);
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY t1 ALL NULL NULL NULL NULL 7 Using where
1 PRIMARY t2 ref idx idx 5 test.t1.a 256 Using index; FirstMatch(t1)
1 PRIMARY t2 range idx idx 5 NULL 2 Using where; Using index; Using join buffer (flat, BNL join)
1 PRIMARY t1 ALL NULL NULL NULL NULL 5 Using where
1 PRIMARY t2 ref idx idx 5 test.t1.a 1463 Using index; FirstMatch(t1)
1 PRIMARY t2 range idx idx 5 NULL 5 Using where; Using index; Using join buffer (flat, BNL join)
explain
select a from t1 join t2 on b between 1 and 2 and a in (select b from t2);
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY t1 ALL NULL NULL NULL NULL 7 Using where
1 PRIMARY t2 ref idx idx 5 test.t1.a 256 Using index; FirstMatch(t1)
1 PRIMARY t2 range idx idx 5 NULL 2 Using where; Using index; Using join buffer (flat, BNL join)
1 PRIMARY t1 ALL NULL NULL NULL NULL 5 Using where
1 PRIMARY t2 ref idx idx 5 test.t1.a 1463 Using index; FirstMatch(t1)
1 PRIMARY t2 range idx idx 5 NULL 5 Using where; Using index; Using join buffer (flat, BNL join)
drop table t1,t2;
set optimizer_switch= @tmp_mdev12675;
#