Re: advantages/disads of primary keys and indices?

I see, What about if you had 3 or 4 columns that would always be unique, is there an advantage to naming them as primary keys? does this slow inserts because it has to check if theres a duplicate entry? ""Manuel Lemos"" <mlemos@acm.org> wrote in message news:618.573T978T13634015mlemos@acm.org... > Hello Noah, > > On 22-Jun-01 21:17:35, you wrote: > > >what are the advantages and disadvantages of primary keys and indices? > > A primary key is a unique index. > > Use indexes for the fields that will be most looked up in the first > condition of the WHERE clause of your SQL queries, especially if your > tables will hold many values, but beware that indexes also take disk space. > > > Regards, > Manuel Lemos > > Web Programming Components using PHP Classes. > Look at: http://phpclasses.UpperDesign.com/?user=mlemos@acm.org > -- > E-mail: mlemos@acm.org > URL: http://www.mlemos.e-na.net/ > PGP key: http://www.mlemos.e-na.net/ManuelLemos.pgp > -- > > > -- > PHP Database Mailing List (http://www.php.net/) > To unsubscribe, e-mail: php-db-unsubscribe@lists.php.net > For additional commands, e-mail: php-db-help@lists.php.net > To contact the list administrators, e-mail: php-list-admin@lists.php.net >