1drop table if exists t; 2create table t (id int not null, x int not null, y int not null, primary key(id), key(x)) engine=tokudb; 3insert into t values (0,0,0),(1,1,1),(2,2,2),(3,2,3),(4,2,4); 4explain select x,id from t force index (x) where x=0 and id=0; 5id select_type table type possible_keys key key_len ref rows Extra 61 SIMPLE t const x x 8 const,const 1 Using index 7flush status; 8select x,id from t force index (x) where x=0 and id=0; 9x id 100 0 11show status like 'handler_read%'; 12Variable_name Value 13Handler_read_first 0 14Handler_read_key 1 15Handler_read_last 0 16Handler_read_next 0 17Handler_read_prev 0 18Handler_read_retry 0 19Handler_read_rnd 0 20Handler_read_rnd_deleted 0 21Handler_read_rnd_next 0 22explain select y,id from t force index (x) where x=0 and id=0; 23id select_type table type possible_keys key key_len ref rows Extra 241 SIMPLE t const x x 8 const,const 1 25flush status; 26select y,id from t force index (x) where x=0 and id=0; 27y id 280 0 29show status like 'handler_read%'; 30Variable_name Value 31Handler_read_first 0 32Handler_read_key 1 33Handler_read_last 0 34Handler_read_next 0 35Handler_read_prev 0 36Handler_read_retry 0 37Handler_read_rnd 0 38Handler_read_rnd_deleted 0 39Handler_read_rnd_next 0 40explain select x,id from t force index (x) where x=0 and id=1; 41id select_type table type possible_keys key key_len ref rows Extra 421 SIMPLE t const x x 8 const,const 1 Using index 43flush status; 44select x,id from t force index (x) where x=0 and id=1; 45x id 46show status like 'handler_read%'; 47Variable_name Value 48Handler_read_first 0 49Handler_read_key 1 50Handler_read_last 0 51Handler_read_next 0 52Handler_read_prev 0 53Handler_read_retry 0 54Handler_read_rnd 0 55Handler_read_rnd_deleted 0 56Handler_read_rnd_next 0 57explain select y,id from t force index (x)where x=0 and id=1; 58id select_type table type possible_keys key key_len ref rows Extra 591 SIMPLE t const x x 8 const,const 1 60flush status; 61select y,id from t force index(x) where x=0 and id=1; 62y id 63show status like 'handler_read%'; 64Variable_name Value 65Handler_read_first 0 66Handler_read_key 1 67Handler_read_last 0 68Handler_read_next 0 69Handler_read_prev 0 70Handler_read_retry 0 71Handler_read_rnd 0 72Handler_read_rnd_deleted 0 73Handler_read_rnd_next 0 74explain select x,id from t force index (x) where x=2 and id=3; 75id select_type table type possible_keys key key_len ref rows Extra 761 SIMPLE t const x x 8 const,const 1 Using index 77flush status; 78select x,id from t force index (x) where x=2 and id=3; 79x id 802 3 81show status like 'handler_read%'; 82Variable_name Value 83Handler_read_first 0 84Handler_read_key 1 85Handler_read_last 0 86Handler_read_next 0 87Handler_read_prev 0 88Handler_read_retry 0 89Handler_read_rnd 0 90Handler_read_rnd_deleted 0 91Handler_read_rnd_next 0 92explain select x,id from t force index (x) where x=2 and id=0; 93id select_type table type possible_keys key key_len ref rows Extra 941 SIMPLE t const x x 8 const,const 1 Using index 95flush status; 96select x,id from t force index (x) where x=2 and id=0; 97x id 98show status like 'handler_read%'; 99Variable_name Value 100Handler_read_first 0 101Handler_read_key 1 102Handler_read_last 0 103Handler_read_next 0 104Handler_read_prev 0 105Handler_read_retry 0 106Handler_read_rnd 0 107Handler_read_rnd_deleted 0 108Handler_read_rnd_next 0 109drop table t; 110