On Thu, 2008-03-06 at 07:28 -0800, Craig James wrote: ... > My question is: What do the other databases do that Postgres can't do, and > why not? > > Count() on Oracle and MySQL is almost instantaneous, even for very large > tables. So why can't Postgres do what they do? ...
I can vouch that Oracle can still take linear time to perform a count(*), at least in some cases. I have also seen count(*) fast in some cases too... my understanding is that they maintain a list of "interested transactions" on a per-relation basis. Perhaps they do an optimization based on the index size if there are no pending DML transactions? -- Mark -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://mail.postgresql.org/mj/mj_wwwusr?domain=postgresql.org&extra=pgsql-performance
