Subject Re: [ib-support] Rollback and OIT
Author Pavel Cisar

On 21 Feb 2003 at 21:39, c_pradelli c_pradelli@... wrote:

> I have a doubt about OIT.
> The first time you rollback a transaction it becomes the OIT until
> the next sweep or backup-restore. I'm ok?

It's a little bit more complicated :-) There is an undo log for each
transaction maintained in memory, so engine can restore rows immediately
and mark transaction as committed and thus not interesting. But there are
some condition when undo log is not used:

- undo log is disabled (see isc_no_undo_log TPB parameter)
- rollback is not requested by client (for example it's performed
automatically because client died).
- undo log is too big (when undo log exceeds 500 nodes, it's discarded)

Anyway, many rollback commands issued from client doesn't render the
transaction interesting.

> What happend if instead of that, I rollback-retainig the transaction
> and inmediattly after, I commit it?. Will this transaction becomes an
> Interesting Transaction?

Interesting scenario :-) but should not make any difference.

Best regards

Pavel Cisar
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