Wordpress database includes data such as your WordPress site settings, posts, pages and comments and settings for WordPress themes and plugins that you have installed.
Using WP-DBManager plugin
Allows you to optimize database, repair database, backup database, restore database, delete backup database , drop/empty tables and run selected queries. Supports automatic scheduling of backing up and optimizing of database.
1.Download WP-DBManager plugin from http://wordpress.org/extend/plugins/wp-dbmanager/
2.upload this plugin to www.yoursite.com\wp-content\plugins\ folder.