Persistence: a proposal

Patrick Logan
Thu, 22 May 97 14:31 PDT

>>>>> "Scott" == Scott L Burson <> writes:

    Scott> ...although small commits are relatively expensive in
    Scott> ZetaBase, it makes committing tens of megabytes of stuff at
    Scott> a time quite cheap, compared to many of the designs I have
    Scott> seen.

Are you talking about tens of MB of delta or tens of MB of objects,
where the actual delta is less than tens of MB?

What is the expected transaction rate?

Multiple concurrent sessions, i.e. transactions?

Gemstone has fast commits by using binary sequential transaction logs
(optionally on raw partitions) and very well encoded representations
of the deltas to be committed. The work of actually getting the bits
back to the repository is a background task and happens potentially
long after the transaction has been committed (except "full check
points" will write everything back to the repository). Shared object
caches and efficent per-session object tables make these changes
available to multiple sessions without having to make round-trips to
the repository all the time.

I would be interested to find out if it could be tuned to your
characteristics, if you could provide more information.

Patrick Logan       
Voice 503-533-3365            Fax   503-629-8556
Gemstone Systems, Inc