Section 15.4. What s the Big Deal?

15.4. What's the Big Deal?

Why are database backups so hard? Can't I just shut down the database and back up the whole system? These are all questions that may be going through your head. If you already know the answers, feel free to skip to the next section.

Why are we hearing so much about database backups?

The demand for relational database management systems (RDBMSs) has grown exponentially in the last few years. Not only are there more databases, they are faster, larger, and more complex than ever before. Companies are relying increasingly on bigger and bigger databases to store their informationinformation that, if lost, would be irreplaceable. Customers have started to recognize the importance of safeguarding their data, and the demand for better backup and recovery utilities has followed. Database companies and backup product companies have finally responded with utilities that are up to the task at hand.

Why is backing up a database so hard?

Actually, backing up a database isn't that hard. It's restoring the database that has caused many people to go insane! Seriously, though, the reason it is so difficult is that you need a good SA and a good DBA to design a good backup plan. Most people know only one side well. If you or your people know both sides, then consider yourself very lucky. In some companies, it's tough to get both sides to work together.

Can't I just shut down the database and back up the whole system?

In some cases, yes. There are a number of considerations that might prevent you from doing this, including your database platform, whether you are using raw or filesystem files, and whether you need point-in-time recoverynot to mention the loss of availability of the database during such an operation. Those details are covered in appropriate chapters in this book.

Do I have to buy a commercial utility to back up my database?

If you can either back up your database to disk or back its files up hot or cold using a standard backup utility, then the answer is no. If you can't do these things, then you're probably going to need a commercial utility.