In today's world, the security of the data in your database is a primary concern. Privacy concerns and laws often make exposure of corporate data a catastrophic problem. Exposure of personal information such as social security numbers or medical information can bring costly lawsuits or even government fines and litigation. In the Internet age, the theft or exposure of such information can be performed from half a world away. No longer can you just lock the door to the server and remove the floppy disks from the workstations and consider yourself secure. The security issues that you must deal with in the database world involve who can see what when, and they break down into a handful of basic situations:
The data in a specific table should be accessible to some users but not others.
Some users should be able to modify particular tables, but other users should not.
In some instances, access to tables should be broken down into columns of the tables. One set of users should be able to see columns a, b, and d, while another set of users should be able to access only columns c, e, and f.
In other instances, the access to tables should be limited by rows. Perhaps department managers should be able to see data about their department but not data about other departments.
This chapter describes the methods that SQL provides to implement this security.
Implementing the security system and enforcing the required restrictions are the responsibility of the ...