On Fri, 2006-04-07 at 13:36 -0400, Tom Lane wrote: > I wrote: > > Rafael Martinez Guerrero <r.m.guerrero@xxxxxxxxxxx> writes: > >> I have a sql statement that takes 108489.780 ms with 8.0.7 in a > >> RHEL4/amd64linux server with 2xAMD Opteron(tm) Processor 275 2.00GHz / > >> 8GB RAM and only 4193.588 ms with 7.4.12 in a RHEL3/386linux server with > >> 2xIntel(R) Xeon(TM) CPU 2.40GHz / 4GB RAM. > > > I think you've discovered a planner regression. > > Simplified test case using the regression database: > > > explain select * from tenk1 a, tenk1 b > > where (a.ten = b.ten and (a.unique1 = 100 or a.unique1 = 101)) > > or (a.hundred = b.hundred and a.unique1 = 42); > > I've repaired the assertion crash in 8.1/HEAD, but I don't think it's > practical to teach 8.0 to optimize queries like this nicely. The reason > 7.4 can do it is that 7.4 forces the WHERE condition into CNF, ie > [..................] Tom, thank you very much for your help. As I suspected this was a more complicated problem than the configuration of some parameters :( . Good that we have found out this now and not after the upgrade. All our upgrade plans and testing for all our databases have been done for/with 8.0.x (yes, I know 8.1.x is much better, but I am working in a conservative place from the sysadm point of view). We will have to change our plans and go for 8.1 if we want this to work. > My recommendation is to update to 8.1.4 when it comes out. Any idea about when 8.1.4 will be released? Thanks again. -- Rafael Martinez, <r.m.guerrero@xxxxxxxxxxx> Center for Information Technology Services University of Oslo, Norway PGP Public Key: http://folk.uio.no/rafael/
