Subject | Re: Confusion regard transaction isolation levels |
---|---|
Author | csswa |
Post date | 2002-04-18T06:47:53Z |
--- In ib-support@y..., "Wilson, Fred" <fred.wilson@b...> wrote:
understanding of transactions, but as soon as anyone starts to update
a record (via uncommitted sql or an unposted db-linked control)
nobody else should be able to edit it *until* the first person elects
to commit or rollback. Possibly what you mean is the duration of the
transactions. Person 1's transaction could be in limbo for minutes
because they are working with a form that opens a transaction and
waits for the user to hit a 'commit' button, whereas person 2 could
have a form that only starts/executes/commits the update transaction
when that user hits the 'commit' button. This is my understanding of
the situation (corrections appreciated).
Regards,
Andrew Ferguson
> - TxnA starts a transactionwith a
> - TxnB starts a transaction
> - TxnB updates a single row in the table but doesn't commit
> - TxnA updates the same row in the same table and the excute fails
> "deadlock". We would have expected the second person that callscommit to
> fail, not to fail at execution time. It doesn't matter who starttheir
> transaction first, the first one to actually "execute" the SQLstatement
> wins (even without committing).No, that seems right to me, Fred. I don't have an in-depth
> What are we missing. This doesn't seem "correct"
understanding of transactions, but as soon as anyone starts to update
a record (via uncommitted sql or an unposted db-linked control)
nobody else should be able to edit it *until* the first person elects
to commit or rollback. Possibly what you mean is the duration of the
transactions. Person 1's transaction could be in limbo for minutes
because they are working with a form that opens a transaction and
waits for the user to hit a 'commit' button, whereas person 2 could
have a form that only starts/executes/commits the update transaction
when that user hits the 'commit' button. This is my understanding of
the situation (corrections appreciated).
Regards,
Andrew Ferguson