MySQL between index usage
Indexes are used to find rows with specific column values quickly. ... If there is a choice between multiple indexes, MySQL normally uses the index that ... ,The query plan for the OR case appears to indicate that MySQL is indeed using indexes, so evidently yes, it can do, at least in this case. ,Only if two employees were born on the same day is the SUBSIDIARY_ID used to sort these records. The query, however, covers a date range. The ordering of ... ,How many rows do you have? Sometimes an index is not used if the optimizer deems it unnecessary (for instance, if the number of rows in your ... ,It can be used for a single-part or multiple-part index. ... BETWEEN , != , or <> operators, or LIKE comparisons if the argument to LIKE is a constant ... ,Index and optimizer hints may be used separately or together. ... To affect only the indexes used when MySQL decides how to find rows in the table and how ... ,This query uses the index. The select type is range , used key is Created For range types, the ref column is always null, ,10664916 records — I hope it is INT UNSIGNED (not signed). I presume you are not worrying about IPv6? Range tests like IP-addresses are difficult.,2018年4月13日 — Or perhaps something I haven't thought of yet? Edit: Strangely, the index is used for certain values. For example: explain select * from geo_ip ... ,2016年8月14日 — NOTE consecutive query execution time is 1 second with same indexes. I read mysql buffers the table data and so consecutive query execution is ...
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 MySQL between index usage 相關參考資料
8.3.1 How MySQL Uses Indexes
Indexes are used to find rows with specific column values quickly. ... If there is a choice between multiple indexes, MySQL normally uses the index that ... https://dev.mysql.com Can MySQL use Indexes when there is OR between conditions?
The query plan for the OR case appears to indicate that MySQL is indeed using indexes, so evidently yes, it can do, at least in this case. https://stackoverflow.com Greater, Less and BETWEEN - Use The Index, Luke
Only if two employees were born on the same day is the SUBSIDIARY_ID used to sort these records. The query, however, covers a date range. The ordering of ... https://use-the-index-luke.com Index for BETWEEN operation in MySql - Stack Overflow
How many rows do you have? Sometimes an index is not used if the optimizer deems it unnecessary (for instance, if the number of rows in your ... https://stackoverflow.com MySQL 8.0 Reference Manual :: 8.2.1.2 Range Optimization
It can be used for a single-part or multiple-part index. ... BETWEEN , != , or <> operators, or LIKE comparisons if the argument to LIKE is a constant ... https://dev.mysql.com MySQL 8.0 Reference Manual :: 8.9.4 Index Hints
Index and optimizer hints may be used separately or together. ... To affect only the indexes used when MySQL decides how to find rows in the table and how ... https://dev.mysql.com MySQL BETWEEN two datetimes does not use INDEX - Stack ...
This query uses the index. The select type is range , used key is Created For range types, the ref column is always null, https://stackoverflow.com MySQL index to get record between 2 columns used for range
10664916 records — I hope it is INT UNSIGNED (not signed). I presume you are not worrying about IPv6? Range tests like IP-addresses are difficult. https://stackoverflow.com MySQL: Optimal index for between queries - Stack Overflow
2018年4月13日 — Or perhaps something I haven't thought of yet? Edit: Strangely, the index is used for certain values. For example: explain select * from geo_ip ... https://stackoverflow.com optimization for IN, BETWEEN, ORDER BY and LIMIT query
2016年8月14日 — NOTE consecutive query execution time is 1 second with same indexes. I read mysql buffers the table data and so consecutive query execution is ... https://dba.stackexchange.com |