"Martijn Tonies" wrote:

>> > It's advisable to commit in batches of about 5000 - 8000 records,
>> > especially if you don't have a lot of memory on the server. The server
>> > builds up an auto-undo log structure in memory for inserts, which will
> be
>> > reset when the transaction commits.
>>
>> Right, but Firebird is clever enough to not hold undo-logs
>> for _all_ commands executed inside transaction.
>> After some point the undo-logs are discarded.
>
> Huh? How does a "rollback" work then?

Check the archives - how does multiversion architecture work
and what is garbage collection.
:-)

Ivan