Purpose of database System

Drawback of using file system (cont.)

1.        atomicity of update

• Failures may Leave Database in an inconsistent state with partial update carried out.

EX: Transfer of found from one account to anther should either complete or not happen at all.

• Concurrent accessed By multiple user
• concurrent acessed needed for performance.
• uncontrolled concurrent accesses can lead to inconsistencies  .

EX: Two people reading a balance and updating it at the same time

• Security problem
• Database Systems offer solutions to all the above problems.