Few days ago I wrote an article about using UNION to implement loose index scan. First I should mention double IN also works same way so you do not have to use the union… | const | 12741 | Using where | | 3 | UNION | people | ref | age | age | 1 | const | 12631 | Using where | |NULL | UNION RESULT | | ALL | NULL | NULL | NULL…
Post: MySQL: Followup on UNION for query optimization, Query profiling
August 14, 2006 By 14 Comments
Post: Using UNION to implement loose index scan in MySQL
August 10, 2006 By 15 Comments
… people WHERE age=18 AND zip IN (12345,12346, 12347) -> UNION ALL -> SELECT name FROM people WHERE age=19 AND zip IN (12345,12346, 12347) -> UNION ALL -> SELECT name FROM people WHERE age=20 AND zip IN (12345,12346, 12347) -> UNION ALL -> SELECT name FROM people WHERE age=21 AND zip…
Comment: How to find wrong indexing with glance view
August 23, 2008 By 27 Comments
…. 1. http://www.mysqlperformanceblog.com/2006/08/10/using-union-to-implement-loose-index-scan-to-mysql/#comment-1695 2. http://dev…
Comment: Using UNION to implement loose index scan in MySQL
August 14, 2006 By 15 Comments
[...] Few days ago I wrote an article about using UNION to implement loose index scan. [...]
