The recent versions of wordpress give the authors an opportunity to revise their posts and repost it. This comes out quite handy but every time you go and revise or edit a post, new rows are added to your database beacause of the ‘autosave’ feature. If you are doing revisions of posts quite often your database is going to be heavily loaded with unneccessary rows. There might be options to change this autosave option but if you are late you can do something like this.
Open your phpmyadmin panel, choose your wp database and run the sql query:
DELETE FROM ‘wp_posts’ WHERE `post_type`=’revision’;
(considering wp_ as the table prefix)
The first time I did that, I got some 200 rows deleted from my database when I had posted only 3 pages and 10 posts. Running this query in intervals of choice keeps the databse clean and may be faster.