mariadb/storage/tokudb/mysql-test/tokudb_bugs/r/2548.result
Sergei Golubchik 642aa4366d clustering == covering
tell the optimizer that every TokuDB "clustering" index is the "covering" index
in the MariaDB optimizer sense.
2013-09-09 14:00:06 +02:00

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1.1 KiB
Text

SET DEFAULT_STORAGE_ENGINE = 'tokudb';
DROP TABLE IF EXISTS foo;
create table foo (a int, b int, c int, primary key (a), key (b) clustering=yes);
replace into foo values (1,10,100), (2,20,200), (1,10,1000);
explain select * from foo;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE foo index NULL b 5 NULL 2 Using index
select * from foo;
a b c
1 10 1000
2 20 200
explain select * from foo order by b desc;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE foo index NULL b 5 NULL 2 Using index
select * from foo order by b desc;
a b c
2 20 200
1 10 1000
insert ignore into foo values (3,30,300), (1,10,1);
Warnings:
Warning 1062 Duplicate entry '1' for key 'PRIMARY'
explain select * from foo;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE foo index NULL b 5 NULL 3 Using index
select * from foo;
a b c
1 10 1000
2 20 200
3 30 300
explain select * from foo order by b desc;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE foo index NULL b 5 NULL 3 Using index
select * from foo order by b desc;
a b c
3 30 300
2 20 200
1 10 1000
drop table foo;