Ühel kenal päeval, R, 2006-06-23 kell 17:27, kirjutas Bruce Momjian: > Jonah H. Harris wrote: > > On 6/23/06, Tom Lane <[EMAIL PROTECTED]> wrote: > > > What I see in this discussion is a huge amount of "the grass must be > > > greener on the other side" syndrome, and hardly any recognition that > > > every technique has its downsides and complications. > > > > I'm being totally objective. I don't think we should abandon > > PostgreSQL's overall design at all, because we do perform INSERTs and > > DELETEs much better than most systems. However, I've looked at many > > systems and how they implement UPDATE so that it is a scalable > > operation. Sure, there are costs and benefits to each implementation, > > but I think we have some pretty brilliant people in this community and > > can come up with an elegant design for scalable UPDATEs. > > I think the UPDATE case is similar to the bitmap index scan or perhaps > bitmap indexes on disk --- there are cases we know can not be handled > well by our existing code, so we have added (or might add) these > features to try to address those difficult cases.
Not really. Bitmap index scan and bitmap index are both new additions working well with existing framework. While the problem of slowdown on frequent updates is real, the suggested fix is just plain wrong, as it is based on someones faulty assumption on how index lookup works, and very much simplified view of how different parts of the system work to implement MVCC. The original fix he "suggests" was to that imagined behaviour and thus ignored all the real problems of such change. All the next suggestions were variations of the first ones, and failed to address or even research any problems brought up. -- ---------------- Hannu Krosing Database Architect Skype Technologies OÜ Akadeemia tee 21 F, Tallinn, 12618, Estonia Skype me: callto:hkrosing Get Skype for free: http://www.skype.com ---------------------------(end of broadcast)--------------------------- TIP 1: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly