mirror of
https://github.com/MariaDB/server.git
synced 2025-10-31 15:50:51 +03:00
699291a8e6
- Make the range-et-al optimizer produce E(#table records after table
condition is applied),
- Make the join optimizer use this value,
- Add "filtered" column to EXPLAIN EXTENDED to show
fraction of records left after table condition is applied
- Adjust test results, add comments
12 lines
438 B
Plaintext
12 lines
438 B
Plaintext
drop table if exists t1;
|
|
create table t1(n int not null, key(n)) delay_key_write = 1;
|
|
select count(distinct n) from t1;
|
|
count(distinct n)
|
|
100
|
|
explain extended select count(distinct n) from t1;
|
|
id select_type table type possible_keys key key_len ref rows filtered Extra
|
|
1 SIMPLE t1 index NULL n 4 NULL 200 100.00 Using index
|
|
Warnings:
|
|
Note 1003 select count(distinct `test`.`t1`.`n`) AS `count(distinct n)` from `test`.`t1`
|
|
drop table t1;
|