On Tuesday 2006-06-13 16:19, Jim C. Nasby wrote: > On Mon, May 15, 2006 at 12:24:51PM -0700, TJ O'Donnell wrote: > > I've written some extensions to postgres to implement > > chemical structure searching. I get inquiries about > > the performance of postgres vs. oracle. This is a huge > > topic, with lots of opinions and lots of facts. But, > > today I got some feedback stating the opinion that: > > "Postgres performance diminishes with large tables > > (we?ll be going to upwards of hundreds of millions of rows)." > > > > Is this pure speculation, opinion, known fact? > > Does anyone know of measured performance of postgres > > vs. oracle, specifically with very large tables? > > You're more likely to run into problems with large fields being toasted > than plain large tables. IIRC Oracle's large object support is better > than PostgreSQL's. There's more to it that that. If the huge tables grow, VACCUMING for XID maintenance could put Postgres at a disadvantage relative to Oracle. There are "behavioral" variables involved. Furthermore, it may be possible to trade DBA tricks for initial cost of ownership. Usually the accounting doesn't work out (DBA salaries are even more expensive than Oracle licenses) ... but grad students work cheap.
