From: Daevid Vincent Date: April 20 2005 10:49pm Subject: Question about combination PRIMARY keys and INDEX List-Archive: http://lists.mysql.com/mysql/182909 MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit If I have a table with a primary key like this: CREATE TABLE `answers` ( `qid` INT UNSIGNED NOT NULL , `userid` INT UNSIGNED NOT NULL , `groupid` INT UNSIGNED NOT NULL , `comments` TEXT NOT NULL , PRIMARY ( `qid` , `userid` , `groupid` ) ); But I will also be searching in various pages, for all 'answers' from a certain userid or say that belong to a certain groupid, do I still need to create separate INDEXes for those fields, or is it enough to have them in that combination PRIMARY key?