> > Re this talk given by Michael Stonebraker: > > > > http://slideshot.epfl.ch/play/suri_stonebraker > > > > > > > > He makes the claim that in a modern ‘big iron’ RDBMS such as Oracle, > > DB2, MS SQL Server, Postgres, given enough memory that the entire > > database lives in cache, the server will spend 96% of its memory > > cycles on unproductive overhead. This includes buffer management, > > locking, latching (thread/CPU > > conflicts) and recovery (including log file reads and writes). > > > > > > > > [Enough memory in this case assumes that for just about any > business, > > 1TB is enough. The intent of his argument is that a server designed > > correctly for it would run 25x faster.] > > > > > > > > I wondered if there are any figures or measurements on Postgres > > performance in this ‘enough memory’ environment to support or > contest > > this point of view? > > What limits postgresql when everything fits in memory? The fact that > it's designed to survive a power outage and not lose all your data. > > Stonebraker's new stuff is cool, but it is NOT designed to survive > total power failure.
I don't think this is quite true. The mechanism he proposes has a small window in which committed transactions can be lost, and this should be addressed by replication or by a small amount of UPC (a few seconds). But that isn't my question: I'm asking whether anyone *knows* any comparable figures for Postgres. IOW how much performance gain might be available for different design choices. > Two totally different design concepts. It's apples and oranges to > compare them. Not to an end user. A system that runs 10x on OLTP and provides all the same functionality is a direct competitor. Regards David M Bennett FACS Andl - A New Database Language - andl.org -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
