Thanks all. The query I run is a subquery. I noticed joined query run a lot faster than the sub.
This is the subquery: select * from class_c where detail_id in (select classC from item_classification where classb="216") order by detail; This query takes nearly 3 minutes, before it did not take that long. I guess I should use a primary key As an index. I want to be able to add items that I can classify into different classa, classb or classc. Example: Itemid 1025 ClassA: 101 classB: 218 classC: 356 Same item can be put into another class. Itemid 105 ClassA: 101 classb: 218 classC: 357 So not having a primary key/index will slow my queries? -----Original Message----- From: Kishore Jalleda [mailto:[EMAIL PROTECTED] Sent: Thursday, April 27, 2006 10:49 AM To: nngau Cc: mysql@lists.mysql.com Subject: Re: Multiple primary keys On 4/27/06, nngau <[EMAIL PROTECTED]> wrote: > > Can someone figure out what's going on. This is the only change I made > to this table. Basically I don't want any duplicate rows, so I setup 4 > fields to be my primary key. > > When I do a simple select query it takes nearly 30 seconds to complete. > This is affecting my websites and taking a very long time to query the > Products. Have I setup this table right? Thank You!! > > +---------+-------------+------+-----+---------+-------+ > | Field | Type | Null | Key | Default | Extra | > +---------+-------------+------+-----+---------+-------+ > | itemID | int(6) | | PRI | 0 | | > | classA | int(3) | | PRI | 0 | | > | classB | int(3) | | PRI | 0 | | > | classC | int(3) | | PRI | 0 | | > | picture | varchar(10) | YES | | NULL | | > | sex | char(2) | YES | | NULL | | > +---------+-------------+------+-----+---------+-------+ > > > -- > MySQL General Mailing List > For list archives: http://lists.mysql.com/mysql > To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED] > > You can avoid duplicate rows with only one primary key, unless you have a specific reason for having your primary key span on four columns. Your query being slower depends on how you have indexed your columns relating to your queries. Please give us a sample query which is running slowly.. Kishore Jalleda http://kjalleda.googlepages.com/projects -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
