Commit / No Commit
Commit will always tell you commit complete But that does not necessarily mean you got what you wanted. Try typing commit; without doing anything, and you will see that you will get the same message. You need to know when oracle does a commit without your asking. For example, creating a table commits the previous information.
The Following actions generate an implicit commit:
1. Quit or exit
2. Create a Table or View (DDL)
3. Drop table, view, and grant
5. Connect, Disconnect
6. Alter, Audit, noAudit.
We can conclude that the commands like update which just changes the contents are not commited and commands like alter, drop which manipulates the table structure are autocommited. It is from the perspective of the table manipulations.