Brian Wipf <brian@xxxxxxxxxxx> wrote: > I'm trying to optimize a PostgreSQL 8.1.5 database running on an > Apple G5 Xserve (dual G5 2.3 GHz w/ 8GB of RAM), running Mac OS X > 10.4.8 Server. > > The queries on the database are mostly reads, and I know a larger > shared memory allocation will help performance (also by comparing it > to the performance of the same database running on a SUSE Linux box, > which has a higher shared_buffers setting). > > When I set shared_buffers above 284263 (~ 2.17 GB) in the > postgresql.conf file, I get the standard error message when trying to > start the db: It might be, that you hit an upper limit in Mac OS X: [galadriel: memtext ] cug $ ./test test(291) malloc: *** vm_allocate(size=2363490304) failed (error code=3) test(291) malloc: *** error: can't allocate region test(291) malloc: *** set a breakpoint in szone_error to debug max alloc = 2253 M That seems near the size you found to work. I don't really know much about that, but it seems you just can't alloc more memory than a bit over 2GB. So, be careful with my non-existing knowledge about that ... ;-) cug
