When you say that with a lot of concurrent access, queries get very slow, How many concurrent connections to your server have you had? more that max_connectionsÂvalue? If you want to have many concurrent connections, you should have consider to use a pooling connection system like pgbouncer or pgpool. Which are the values for: - work_mem - shared_buffers - maintenance_work_mem - effective_cache_size - effective_io_concurrency - server_version Which are your platform? Regards -- Ing. Marcos LuÃs OrtÃz Valmaseda System Engineer -- Database Administrator Centro de TecnologÃas de GestiÃn de Datos (DATEC) Universidad de las Ciencias InformÃticas http://postgresql.uci.cu -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance