1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52
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SET DEFAULT_STORAGE_ENGINE = 'tokudb';
DROP TABLE IF EXISTS foo;
set session unique_checks=off;
create table foo (a int, b int, c int, primary key (a), key(b));
insert into foo values (1,10,100),(2,20,200),(3,30,300),(4,40,400),(5,50,500),(6,60,600);
explain select * from foo;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE foo ALL NULL NULL NULL NULL 6
select * from foo;
a b c
1 10 100
2 20 200
3 30 300
4 40 400
5 50 500
6 60 600
explain select b from foo;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE foo index NULL b 5 NULL 6 Using index
select b from foo;
b
10
20
30
40
50
60
replace into foo values (1,1,1);
explain select * from foo;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE foo ALL NULL NULL NULL NULL 6
select * from foo;
a b c
1 1 1
2 20 200
3 30 300
4 40 400
5 50 500
6 60 600
explain select b from foo;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE foo index NULL b 5 NULL 6 Using index
select b from foo;
b
1
20
30
40
50
60
set session unique_checks=on;
DROP TABLE foo;
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