Re: Queries becoming slow under heavy load

When you say that with a lot of concurrent access, queries get very slow, How many concurrent connections to your
serverhave you had? 
more that max_connections´value?
If you want to have many concurrent connections, you should have consider to use a pooling connection system like
pgbounceror 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 Luís Ortíz Valmaseda
System Engineer -- Database Administrator

Centro de Tecnologías de Gestión de Datos (DATEC)
Universidad de las Ciencias Informáticas
http://postgresql.uci.cu