Hi, If you have that date column in your where clause for example:
SELECT ...... FROM ..... WHERE tstamp > NOW() - INTERVAL 1 WEEK; Then it's essential to index that column to speed up a table with lots of data. On a table with many rows, an index on a timestamp column is invaluable. However, I should point out that having an index on a column does add a small performance overhead to inserts and updates so if you're not going to use it in your where clauses then there's not much point in adding it. Cheers, Andrew -----Original Message----- From: Cantwell, Bryan [mailto:bcantw...@firescope.com] Sent: 24 April 2009 22:56 To: mysql@lists.mysql.com Subject: Index time columns? I have a debate with someone about indexes on time columns. So I ask the community, should you put an index on a timestamp column of a table? Thanks...