Hello,

Till recently I've been using successfully the org.hibernate.id.enhanced.TableGenerator id generator, but now I came across an interesting problem:

I have a table that both hibernate and non-hibernate processes access and insert new rows into, possibly simultaneously.
Therefore I no longer can use the sequence approach, as the non-hibernate process is not aware of the sequence-like table used by hibernate, and does not increment the appropriate value.

Neither can I use the increment generator, as it is not protected against simultaneous access.

The hi/lo generator is as well unsuitable, if I understand correctly, as the non-hibernate process will not use it, therefore the generator might return already used value.

Therefore, the only solution that I see is to implement my own indicator, or have I missed anything?

Any help is highly appreciated,
Vitaliy

No. As your your options are dependent on what controls you have over the other processes insert operations into the DB.

Therefore I need to implement locking mechanisms as well?
Lets say that I'll write a class that would implement id generation.

So, I'll have to lock the table for inserts from the moment that I've generated the id, till the moment that the object had actually been flushed into the database by hibernate (otherwise the id generated might not be unique - as it might have been already used by some other non hibernate process which uses some different id generation strategy in the time between the generation and the actual insert).

How can I minimize this time, and also know when the flush had actually occurred? I would like not to use database triggers, as they are database dependent?

Thanks allot,
Vitaliy

Are any other details requiered?

Thanks,
Vitaliy