Do file persistence managers perform 'real' transactions?

[damncho]

Hi, I was having some problems with the performance of data base transaction in the MQ. (See my previous messagess where file persistence manager was much much faster with transaction turned on than jdbc2 manager)

So I wanted to use file system for persistence manager, but I was told that file persistence manager is probably not transactional - it just fakes it. Can anyone tell me if it is true? I could not find anything to prove or dis-prove this.

[adrian.brock]

I find it the other way around,
except for non persistent messages when memory is short.
Then the memory used by the sql statement's StringBuffers
cause more messages than necessary to be written to disk.

The transactions are real.
JBossMQ implements XA.
The transactions are logged to persistent storage so
they can be recovered after a server failure.
The recovery doesn't scale very well (large number of
messages).

Regards,
Adrian