Hi

i have a FOR UPDATE trigger in one of my tables

What i do is after the update is done, i update one of the columns of the table

Is it possible, that between the time the update is done and the time the trigger starts (and finishes) someone changes something in the same row?

Or does the DBMS lock everything up from the time the update starts and the trigger finishes

Thank you

I don’t know the answer to the question but I suspect it could happen. If you wish to prevent I would wrap the update and trigger in a single transaction to ensure integrity.

The trigger fires as part of the same transaction that modified the row. Consequently, the rows affected are locked until all of the triggers are fired and executed <bad pun>I know that sounds harsh, but some RDBMS believe in the Death Penalty, not just terminating employment</bad pun>.

Sidenote: if you rollback during the trigger then the whole transaction is rolled back

David Lundell
Principal Consultant and Trainer
www.mutuallybeneficial.com