WebThe EXPLAIN statement produces extra ( “extended”) information that is not part of EXPLAIN output but can be viewed by issuing a SHOW WARNINGS statement following … WebSimilar to the Using index table access method, Using index for group-by indicates that MySQL found an index that can be used to retrieve all columns of a GROUP BY or DISTINCT query without any extra disk access to the actual table. Additionally, the index is used in the most efficient way so that for each group, only a few index entries are read.
mysql - Create a proper index for query - Database …
WebThe possible_keys column only lists the indexes specified in the USE INDEX clause. The key column has both idx_name_fl and idx_name_lf. It means that the Query Optimizer … WebDec 21, 2024 · Extra = Using sort_union(date_executed_idx,is_executing_idx); Using where; Table is InnoDB (MySql database). I really can't understand why it isn't able to use tasks_2_idx index on the PRIMARY query. At the moment, instead of 35 tasks extracted/executed per minute I get 5-6 tasks executed per minute (because each … snohomish county e-filing
Essential Guide To MySQL USE INDEX Hint By Examples
WebJul 29, 2024 · MySQL执行计划 Extra出现Using index condition 原因与解决方法. Extra中using index condition代表查询条件中虽然出现了索引列，但是有部分条件无法使用索 … Webこのセクションでは、EXPLAIN によって生成される出力カラムについて説明します。 あとのセクションで、type と Extra カラムに関する追加情報を提供します。 EXPLAIN からの各出力行は 1 つのテーブルに関する情報を提供します。 各行には、表8.1「EXPLAIN 出力カラム」で要約し、次の表に詳しく説明 ... WebThe EXPLAIN statement produces extra ( “extended”) information that is not part of EXPLAIN output but can be viewed by issuing a SHOW WARNINGS statement following EXPLAIN. As of MySQL 8.0.12, extended information is available for SELECT , DELETE , INSERT , REPLACE, and UPDATE statements. Prior to 8.0.12, extended information is … snohomish county dpw rules