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create table test_table (id int, random_data varchar(36), static_int int, static_varchar varchar(10));
insert into test_table(id, random_data, static_int, static_varchar)
select id, random_data, 42, 'Hello'
from (
with recursive data_generator(id, random_data) as (
select 1 as id, uuid() as random_data
union all
select id + 1, uuid() from data_generator where id < 1000
)
select * from data_generator
) as a;
commit;
analyze table test_table;
Table Op Msg_type Msg_text
test.test_table analyze status OK
explain select * from (select id, lead(id) over(order by id) next_id from test_table order by id) a limit 10;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY <derived2> ALL NULL NULL NULL NULL 1000
2 DERIVED test_table ALL NULL NULL NULL NULL 1000 Using temporary; Using filesort
select * from (select id, lead(id) over(order by id) next_id from test_table order by id) a limit 10;
id next_id
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drop table if exists test_table;
create table test_table (id int, random_data varchar(36), static_int int, static_varchar varchar(10));
insert into test_table(id, random_data, static_int, static_varchar)
select id, random_data, 42, 'Hello'
from (
with recursive data_generator(id, random_data) as (
select 1 as id, uuid() as random_data
union all
select id + 1, uuid() from data_generator where id < 100000
)
select * from data_generator
) as a;
commit;
analyze table test_table;
Table Op Msg_type Msg_text
test.test_table analyze status OK
explain select * from (select id, lead(id) over(order by id) next_id from test_table order by id) a limit 10;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY <derived2> ALL NULL NULL NULL NULL 100000
2 DERIVED test_table ALL NULL NULL NULL NULL 100000 Using temporary; Using filesort
flush status;
select * from (select id, lead(id) over(order by id) next_id from test_table order by id) a limit 10;
id next_id
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select variable_name,
case when variable_value > 0 then 'WITH PASSES' else 'NO PASSES' end
from information_schema.session_status
where variable_name like 'Sort_merge_passes';
variable_name case when variable_value > 0 then 'WITH PASSES' else 'NO PASSES' end
SORT_MERGE_PASSES WITH PASSES
drop table test_table;
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