Postgres vs. intel ccNUMA on Linux

Hackers,

Any tips / conventional wisdom regarding running postgres on large-
ish memory ccNUMA intel machines, such as a 32G dual-quad-core,
showing two NUMA nodes of 16G each? I expect each postgres backend's
non-shared memory usage to remain nice and reasonably sized, hopefully
staying within the confines of its processor's local memory region,
but how will accesses to shared memory and / or buffer cache play out?
Do people tune their backends via 'numactl' ?

Furthermore, if one had more than one database being served by the
machine, would it be advisable to do this via multiple clusters
instead of a single cluster, tweaking the processor affinity of each
postmaster accordingly, trying to ensure each cluster's shared memory
segments and buffer cache pools remain local for the resulting backends?

Thanks!
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James Robinson
Socialserve.com