[Charset iso-8859-1 unsupported, filtering to ASCII...]
> > > Well, so, before replacing anything we would have to add
> > > MVCC to BDB. I still didn't look at your sources, 'll do
> > > in a few days...
> >
> > Vadim, I thought you said you were going to be doing a new storage
> > manager for 7.2, including an over-write storage manager that
> > keeps MVCC tuples in a separate location. Could SDB work in that
> > environment easier, without having MVCC integrated into SDB?
>
> How can we integrate SDB code into PostgreSQL without MVCC support
> in SDB if we still want to have MVCC?! I missed something?
> Or you ask is replacement+changes_in_SDB_for_MVCC easier than
> WAL+new_our_smgr? I don't know.
You stated that the new storage manager will do over-writing, and that
the MVCC-needed tuples will be kept somewhere else and removed when not
needed.
It is possible to use SDB, and keep the MVCC-needed tuples somewhere
else, also in SDB, so we don't have to add MVCC into the SDB existing
code, we just need to use SDB to implement MVCC.
The issue was that SDB does two-phase locking, and I was asking if MVCC
could be layered on top of SDB, rather than being added into SDB.
-- Bruce Momjian | http://www.op.net/~candle pgman@candle.pha.pa.us | (610)
853-3000+ If your life is a hard drive, | 830 Blythe Avenue + Christ can be your backup. | Drexel Hill,
Pennsylvania19026