I have several Linux-x68_64 based dedicated PostgreSQL servers where I'm experiencing significant swap usage growth over time. All of them have fairly substantial amounts of RAM (not including swap), yet the amount of swap that postgres is using ramps up over time and eventually hurts performance badly. In every case, simply restarting postgresql frees up all the swap in use (until it ramps up again later). I'm assuming that I have at least one postgresql.conf parameter set wrong, but I'm not sure which. I read that (max_connections * work_mem) should never exceed physical RAM, and if that's accurate, then I suspect that's the root of my problem on systemA (below). However, I'd like confirmation before I start tweaking things, as one of these servers is in production, and I can't easily tweak settings to experiment (plus this problem takes a few weeks before swapping gets bad enough to impact performance). A few examples: 0) system A: 56GB RAM, running postgresql-8.4.8 with the following parameters: maintenance_work_mem = 96MB effective_cache_size = 40GB work_mem = 256MB wal_buffers = 16MB shared_buffers = 13GB max_connections = 300 1) system B: 120GB RAM, running postgresql-9.0.4 with the following parameters: maintenance_work_mem = 1GB effective_cache_size = 88GB work_mem = 576MB wal_buffers = 4MB shared_buffers = 28GB max_connections = 200 thanks -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
