Your database contains all your important information if the database is erased or corrupted you lose everything.
Sometimes accident can happen when we least expert it. If you can have made a careless mistake and your database is gone how can you restore your data in your database?
So Backup your database regularly.
If you are use WordPress so you can use backup plugins for take database backup.
WP-Database-Backup :When plugin is installed and active. you can backup your blog database easily in single click. Some time you have create database backup on your server or localhost and if some one hack your site or you have made some mistake then how can you recover your database which include important information. So it is important to save your database safer place like FTP, on your Email or Dropbox.
We have added new feature in WP Database backup which store your database backup on safer places like FTP, Email, Dropbox. Also you get email after successfully database backup created.