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73 lines
2.4 KiB
Text
73 lines
2.4 KiB
Text
create table test_table (id int, random_data varchar(36), static_int int, static_varchar varchar(10));
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insert into test_table(id, random_data, static_int, static_varchar)
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select id, random_data, 42, 'Hello'
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from (
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with recursive data_generator(id, random_data) as (
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select 1 as id, uuid() as random_data
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union all
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select id + 1, uuid() from data_generator where id < 1000
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)
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select * from data_generator
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) as a;
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commit;
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analyze table test_table;
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Table Op Msg_type Msg_text
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test.test_table analyze status Engine-independent statistics collected
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test.test_table analyze status OK
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explain select * from (select id, lead(id) over(order by id) next_id from test_table order by id) a limit 10;
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id select_type table type possible_keys key key_len ref rows Extra
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1 PRIMARY <derived2> ALL NULL NULL NULL NULL 1000
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2 DERIVED test_table ALL NULL NULL NULL NULL 1000 Using temporary; Using filesort
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select * from (select id, lead(id) over(order by id) next_id from test_table order by id) a limit 10;
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id next_id
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1 2
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2 3
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3 4
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4 5
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5 6
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6 7
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7 8
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8 9
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9 10
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10 11
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drop table if exists test_table;
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create table test_table (id int, random_data varchar(36), static_int int, static_varchar varchar(10));
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insert into test_table(id, random_data, static_int, static_varchar)
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select id, random_data, 42, 'Hello'
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from (
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with recursive data_generator(id, random_data) as (
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select 1 as id, uuid() as random_data
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union all
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select id + 1, uuid() from data_generator where id < 100000
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)
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select * from data_generator
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) as a;
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commit;
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analyze table test_table;
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Table Op Msg_type Msg_text
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test.test_table analyze status Engine-independent statistics collected
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test.test_table analyze status OK
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explain select * from (select id, lead(id) over(order by id) next_id from test_table order by id) a limit 10;
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id select_type table type possible_keys key key_len ref rows Extra
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1 PRIMARY <derived2> ALL NULL NULL NULL NULL 100000
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2 DERIVED test_table ALL NULL NULL NULL NULL 100000 Using temporary; Using filesort
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flush status;
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select * from (select id, lead(id) over(order by id) next_id from test_table order by id) a limit 10;
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id next_id
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1 2
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2 3
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3 4
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4 5
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5 6
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6 7
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7 8
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8 9
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9 10
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10 11
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select variable_name,
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case when variable_value > 0 then 'WITH PASSES' else 'NO PASSES' end
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from information_schema.session_status
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where variable_name like 'Sort_merge_passes';
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variable_name case when variable_value > 0 then 'WITH PASSES' else 'NO PASSES' end
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SORT_MERGE_PASSES WITH PASSES
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drop table test_table;
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