31 lines
1.3 KiB
Plaintext
31 lines
1.3 KiB
Plaintext
set tidb_cost_model_version=1;
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drop table if exists t;
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create table t (id int, c1 timestamp);
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show columns from t;
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explain t;
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describe t;
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desc t;
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desc t c1;
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desc t id;
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drop table if exists t;
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create table t(id int primary key, a int, b int);
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set session tidb_hashagg_partial_concurrency = 1;
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set session tidb_hashagg_final_concurrency = 1;
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explain format = 'plan_tree' select group_concat(a) from t group by id;
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explain format = 'plan_tree' select group_concat(a, b) from t group by id;
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explain format = TRADITIONAL select group_concat(a, b) from t group by id;
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explain format = 'row' select group_concat(a, b) from t group by id;
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drop table t;
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drop view if exists v;
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create view v as select cast(replace(substring_index(substring_index("",',',1),':',-1),'"','') as CHAR(32)) as event_id;
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desc v;
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# should use index lookup after adding user index, table scan is not expected
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explain format = 'plan_tree' select * from mysql.user where user = 'xxx';
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explain format = 'plan_tree' select * from mysql.user where user = 'xxx' or user = 'yyy';
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explain format = 'plan_tree' select * from mysql.global_priv where user = 'xxx';
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explain format = 'plan_tree' select * from mysql.global_grants where user = 'xxx' or user = 'yyy';
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explain format = 'plan_tree' select * from mysql.db where user = 'xxx';
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