TCL- (Transmission Control Language)

1) COMMIT

Saves all pending changes permanent.

Example

COMMIT;

2) SAVEPOINT

It is a marker. It is used to identify a point to which you can roll back later. If two save point have same name then when you rollback will done until the last occurrence of the save point.

Example

SAVEPOINT A;

3) ROLLBACK

Discard all pending changes

Example

To discard all pending changes

ROLLBACK;

To discard to particular save point

ROLLBACK TO B;

4) SET TRANSACTION

It is used to set current transaction to read only and read write. This dosen’t affects other transaction by other users. To end this transaction use ‘COMMIT’ or ‘ROLLBACK’. Name is the transaction name given by user.

Example 1

SET TRANSACTION READ ONLY NAME 'TORENTO';

Example 2

SET TRANSACTION READ WRITE NAME 'TORENTO';