Re: Powergres (was Re: Errors on restoring a 7.1.2 dump to 7.3.3)

Ron Johnson <ron(dot)l(dot)johnson(at)cox(dot)net> writes:
> What makes Powergres special? From looking at the pretty pictures
> (and ignoring the squiggly lines), it looks like replication.

Not sure if there's any replication in it. My understanding is that
it amounts to ripping out the lowest layers of the Postgres code and
bolting in Fujitsu's proprietary storage engine (originally developed
for some other DBMS) instead. The Fujitsu people say that this gives
some significant performance improvements, and for all I know it might
do replication too. But I've not yet seen a straight answer about
whether their code preserves MVCC semantics, rollback-able DDL changes,
and other nice stuff that the regular PG code provides. This report
from Stuart isn't exactly giving me warm fuzzies about the robustness
of Fujitsu's code, either.

regards, tom lane