Question

I have a table with the following schema:

CREATE TABLE IF NOT EXISTS `feeds` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `external_id` varchar(255) DEFAULT NULL,
  `user_id` int(11) DEFAULT NULL,
  `name` varchar(255) DEFAULT NULL,
  `notes` text,
  `image_id` int(11) DEFAULT NULL,
  `location_id` int(11) DEFAULT NULL,
   PRIMARY KEY (`id`),
) ENGINE=MyISAM  DEFAULT CHARSET=latin1 AUTO_INCREMENT=9046 ;

I am creating indexes on external_id and location_id they are meant to be used separately for different queries that effect the table. I understand that MySQL will have to rebuild the indexes every time a record is added or updated or deleted. What I cannot figure out is if updating the name field of a record in this table will cause either or both indexes to be rebuilt. Also, I am wondering, it is the case that these two separate indexes can exist on this table without effecting each others performance negatively? Thank you for your time.

Answer 1

The indexes are not “rebuilt”, but they are updated. Altering data in columns that are not indexed should not result in any re-indexing activity.