Hello.
>>> so why does 'explain select * from files where >>> (pathref,version)=(129286,0);' scan the whole table? It is documented that this syntax can't be optimized yet. See: http://dev.mysql.com/doc/mysql/en/row-subqueries.html Jason Pyeron <[EMAIL PROTECTED]> wrote: > On Tue, 6 Sep 2005, Dan Nelson wrote: > >> In the last episode (Sep 06), Jason Pyeron said: >>> there is an unique key index 'pathref_2 (pathref,version)' on this >>> table. >>> >>> so why does 'explain select * from files where >>> (pathref,version)=(129286,0);' scan the whole table? >> >> I have to admit I have never seen this syntax used in a where clause >> before. > > never thought not to use it, SQL servers are just big set processing > engines. > >> Does "where pathref=129286 and version=0" optimize any better? > > yes, it scans only one row. > >> A quick test of mysql-5.0.11 indicates that it doesn't use indexes at >> all with the (field1,field2,..)=(value1,value2,..) syntax. Feel free >> to file a bug :) > > http://bugs.mysql.com/13024 > -- For technical support contracts, goto https://order.mysql.com/?ref=ensita This email is sponsored by Ensita.NET http://www.ensita.net/ __ ___ ___ ____ __ / |/ /_ __/ __/ __ \/ / Gleb Paharenko / /|_/ / // /\ \/ /_/ / /__ [EMAIL PROTECTED] /_/ /_/\_, /___/\___\_\___/ MySQL AB / Ensita.NET <___/ www.mysql.com -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
