From: Claudio Nanni Date: March 29 2009 2:19pm Subject: Re: IN vs. OR on performance List-Archive: http://lists.mysql.com/mysql/216932 Message-Id: <49CF8370.4010706@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit An explain of the two statements yields the same plan, anybody knows if they are actually translated in the same plan? Claudio Ian P. Christian wrote: > 2009/3/29 Oscar : > >> Hi all- >> >> I want to know what the difference between IN and OR is under the hood. >> >> select * from dummy_table where id in (2, 3, 4, 5, 6, 7); >> >> select * from dummy_table where id=2 or id=3 or id=4 or id=5 or id=6 or >> id=7; >> > > I've have thought once the query is compiled, they are the same. What > might cause a difference in performance is doing id > 2 and id <= 7. > > Test it on a large dataset and let us know :) > >