We'd need more information on what the where clauses of the queries look like to assist with this.
-Aaron On 9/5/08, Krishna Chandra Prajapati <[EMAIL PROTECTED]> wrote: > Hi, > > What would you say about the below table . What can i do to make it more > efficient. > > CREATE TABLE mailer_student_status ( > student_id decimal(22,0) NOT NULL default '0', > param varchar(128) NOT NULL default '', > value varchar(128) default NULL, > PRIMARY KEY (student_id,param). > KEY idx_value (value) > ) > > On Sat, Sep 6, 2008 at 1:16 AM, ewen fortune <[EMAIL PROTECTED]> wrote: > >> Hi, >> >> Following on from what Mike mentioned, indexing all columns does not >> really help as MySQL will at most use one index for a query, so its >> important to pick your indexes carefully and consider constructing >> composite indexes. An index on a single column may not even be used >> due to poor cardinality. >> >> Ewen >> >> On Fri, Sep 5, 2008 at 9:27 PM, Krishna Chandra Prajapati >> <[EMAIL PROTECTED]> wrote: >> > Hi all, >> > >> > I am looking for, is there any specific reason for not indexing all >> columns >> > of a table. whats the impact on the performance. Although indexing is >> meant >> > for getting great performance. So, why indexing all columns is not >> > feasible. (Read in docs that all columns should not be indexed) >> > >> > -- >> > Krishna Chandra Prajapati >> > >> > > > > -- > Krishna Chandra Prajapati > -- Sent from my mobile device -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
