Your database can be automatically saved and archived every hour and/or every day, and backups can be emailed to the address you specify. You can also restore the data to your WP DB or an external DB, which makes copying your database to another server and easy task.
Updated March-13th

EZ Backup

Keep your database safe with scheduled backups. Multiple option for off-site backups also available.

tierrainnovation

Render database profiling at the bottom of all WordPress pages. To install, upload <code>wpdb-profiling</code> to the <code>/wp-content/plugins/</code> directory, activate the plugin, and enable / disable features from the wp-admin plugin screen.

WPDB Profiling

This plugin will give you the total number of queries to the db per page, as well as the total time it took to render those queries out to the page.

EZ Backup vs WPDB Profiling