>> total used free shared buffers >> cached >> Mem: 16432296 16273964 158332 0 173536 >> 14321340 >> -/+ buffers/cache: 1779088 14653208 >> Swap: 2096440 560 2095880 > > That certainly looks fine.. And you've got 14G or so which should be > available for this query. Was this near the time the query was running? > Could you give us what 'free' returns when the query is close to the > out-of-memory error? I'd expect the 2nd row under 'free' to be getting > low for the allocation to fail. It was near the time... here's free just before executing the query: total used free shared buffers cached Mem: 16432296 16342056 90240 0 116868 14561200 -/+ buffers/cache: 1663988 14768308 Swap: 2096440 448 2095992 And then here is free close to the time the query runs out of memory (but while the query is still running): total used free shared buffers cached Mem: 16432296 16348260 84036 0 41344 14167384 -/+ buffers/cache: 2139532 14292764 Swap: 2096440 448 2095992 > Uhh.. I saw that your system was 64-bit, but is your PG process > compiled as 64bit? Maybe you're hitting an artificial 32-bit limit, > which isn't exactly helped by your shared_buffers being set up so high > to begin with? Yes, it's compiled as 64-bit: /opt/lms/postgres-8.3_64/bin/postgres: ELF 64-bit LSB executable, AMD x86-64, version 1 (SYSV), for GNU/Linux 2.6.9, dynamically linked (uses shared libs), for GNU/Linux 2.6.9, not stripped We've had nagging memory-related issues with 8.3 that manifest themselves like memory leaks... some posts I've made in the past have led to some leaks getting fixed... but I've not been able to track down more specific causes. It's just that over time Postgres seems to accumulate memory and then we start to see out-of-memory errors like this one. Again, this query could have nothing to do with the root cause, but this is just the example I have to work with at the moment. Regards, Matt -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general