More details. 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) )
SELECT VALUE FROM mailer_student_status WHERE student_id=586925 and VALUE = 0 SELECT VALUE FROM mailer_student_status WHERE PARAM = 'FIRST_MAILER_COUPON_CODE' and VALUE = 0 On Sat, Sep 6, 2008 at 3:04 AM, Aaron Blew <[EMAIL PROTECTED]> wrote: > 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 > -- Krishna Chandra Prajapati
