Martijn van Oosterhout <kleptog@xxxxxxxxx> writes: > On Tue, Feb 09, 2010 at 08:19:51PM +0500, Anton Maksimenkov wrote: >> Can anybody briefly explain me how one postgres process allocate >> memory for it needs? > There's no real maximum, as it depends on the exact usage. However, in > general postgres tries to keep below the values in work_mem and > maintainence_workmem. Most of the allocations are quite small, but > postgresql has an internal allocator which means that the system only > sees relatively large allocations. The majority will be in the order of > tens of kilobytes I suspect. IIRC, the complaint that started this thread was about a VACUUM command failing. Plain VACUUM will in fact start out by trying to acquire a single chunk of size maintenance_work_mem. (On a small table it might not be so greedy, but on a large table it will do that.) So you probably shouldn't ever try to set that value as large as 1GB if you're working in a 32-bit address space. You could maybe do it if you've kept shared_buffers small, but that seems like the wrong performance tradeoff in most cases ... regards, tom lane -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
