mariadb/mysql-test/main/desc_index_min_max.test

--echo #
--echo # MDEV-27576 Use DESC indexes for MIN/MAX optimization
--echo #
--source include/have_sequence.inc
--source include/have_innodb.inc

create or replace table t1 (a int, key(a desc)) engine=innodb;
insert into t1 select seq * 2 from seq_1_to_100 order by rand(1);

let $query=
select max(a) from t1;
eval explain $query;
eval $query;

let $query=
select min(a) from t1;
eval explain $query;
eval $query;

let $query=
select max(a) from t1 where a < 100;
eval explain $query;
eval $query;

let $query=
select min(a) from t1 where a > 100;
eval explain $query;
eval $query;

let $query=
select max(a) from t1 where a <= 100;
eval explain $query;
eval $query;

let $query=
select min(a) from t1 where a >= 100;
eval explain $query;
eval $query;

let $query=
select max(a) from t1 where a <= 99;
eval explain $query;
eval $query;

let $query=
select min(a) from t1 where a >= 99;
eval explain $query;
eval $query;

# the other side

let $query=
select max(a) from t1 where a > 100;
eval explain $query;
eval $query;

let $query=
select max(a) from t1 where a > 1000;
eval explain $query;
eval $query;

let $query=
select min(a) from t1 where a < 100;
eval explain $query;
eval $query;

let $query=
select min(a) from t1 where a < 0;
eval explain $query;
eval $query;

let $query=
select max(a) from t1 where a >= 100;
eval explain $query;
eval $query;

let $query=
select max(a) from t1 where a >= 1000;
eval explain $query;
eval $query;

let $query=
select min(a) from t1 where a <= 100;
eval explain $query;
eval $query;

let $query=
select min(a) from t1 where a <= 0;
eval explain $query;
eval $query;

let $query=
select max(a) from t1 where a >= 99;
eval explain $query;
eval $query;

let $query=
select min(a) from t1 where a <= 99;
eval explain $query;
eval $query;

# double reversion
let $query=
select max(200 - a) from t1;
replace_result 101 100;
eval explain $query;
eval $query;

let $query=
select min(200 - a) from t1;
replace_result 101 100;
eval explain $query;
eval $query;

# more complex key situations
create or replace table t1 (a int, b int, key(a desc, b asc)) engine=innodb;
insert into t1 select seq * 2, seq * 2 from seq_1_to_100 order by rand(1);

let $query=
select max(a) from t1;
eval explain $query;
eval $query;

let $query=
select min(a) from t1;
eval explain $query;
eval $query;

create or replace table t1 (a int, b int, key(a asc), key (b desc)) engine=innodb;
insert into t1 select seq * 2, seq * 2 from seq_1_to_100 order by rand(1);

let $query=
select max(b) from t1;
eval explain $query;
eval $query;

let $query=
select min(b) from t1;
eval explain $query;
eval $query;

create or replace table t1 (a int, b int, key (b desc)) engine=innodb;
insert into t1 select seq * 2, seq * 2 from seq_1_to_100 order by rand(1);

let $query=
select max(b) from t1;
eval explain $query;
eval $query;

let $query=
select min(b) from t1;
eval explain $query;
eval $query;

# float example in the comment
CREATE OR REPLACE TABLE t1 (a FLOAT, KEY (a DESC));
INSERT INTO t1 VALUES (0.1234),(0.6789);
let $query=
SELECT MAX(a) FROM t1 WHERE a <= 0.6789;
eval explain $query;
eval $query;

# Cleanup
drop table t1;
--echo #
--echo # end of test 11.4
--echo #