Ann,

>> IP> Unless you also have some triggers that repeatedly update the same rows,
>> IP> you do not have to commit every "n" inserts, it will not speed up anything.
>>
>> According to my experience, if the available RAM is exhausted by
>> Firebird running a very long transaction, splitting it *will* help
>> performace. I don't know if the OP is inserting thousands or millions
>> of records, so I took the safer approach.

AWH> A transaction, even a long transaction that does lots of inserts should
AWH> not exhaust RAM. Gbak restores entire databases in a single transaction.

well I guess I need to find the cause; I am pretty sure about the
symptoms and the cure, though. One huge transaction -> slow; many
smaller transactions -> fast. Where should I look? Which factor I have
slipped, if it's not RAM?

Ciao
--
Nando Dessena
http://www.flamerobin.org