If the collation for ksd in ..._ci, then it is "case-insensitive", and you can get rid of both calls to LOWER().
> -----Original Message----- > From: Carsten Pedersen [mailto:cars...@bitbybit.dk] > Sent: Tuesday, July 10, 2012 11:22 AM > To: Darek Maciera > Cc: mysql@lists.mysql.com > Subject: Re: Fwd: Query take too long time - please help! > > On 10.07.2012 13:16, Darek Maciera wrote: > > 2012/7/10 Ananda Kumar <anan...@gmail.com>: > >> can u show the explain plan for your query > >> > > > > Thanks, for reply! > > > > Sure: > > > > mysql> EXPLAIN SELECT * FROM books WHERE > > mysql> LOWER(ksd)=LOWER('4204661375'); > > That's definitely not the query you showed the first time around. The > query you're showing here will force a table scan to calculate > LOWER(ksd) for every single row. > > Also, how do you know that ksd id unique (as stated in your original > post)? You have no index on it to ensure uniqueness. > > You'll have to find some other way to query the table. > > Best, > > / Carsten > > -- > MySQL General Mailing List > For list archives: http://lists.mysql.com/mysql > To unsubscribe: http://lists.mysql.com/mysql -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/mysql
