hi, thanks a lot to all of you for your help.
(i'm sorry i did not know how to reply to a certain message) i found that the best number of active connections is indeed 8-10. with 8-10 active connections postgresql did ~170 "account-id"s. this is still only half of what mssql did, but it now makes sence, considering that mssql works close to twice faster. i "played" with work_mem, shared_buffers, temp_buffers. i ran the tests with both of the following configurations, but no significant difference was found. thanks again for any more help. "version";"PostgreSQL 9.1.2 on x86_64-unknown-linux-gnu, compiled by gcc (GCC) 4.1.2 20080704 (Red Hat 4.1.2-46), 64-bit" "bytea_output";"escape" "client_encoding";"UNICODE" "lc_collate";"en_US.UTF-8" "lc_ctype";"en_US.UTF-8" "listen_addresses";"*" "log_destination";"stderr" "log_line_prefix";"%t " "logging_collector";"on" "max_connections";"100" "max_stack_depth";"2MB" "server_encoding";"UTF8" "shared_buffers";"32MB" "TimeZone";"Israel" "wal_buffers";"1MB" "version";"PostgreSQL 9.1.2 on x86_64-unknown-linux-gnu, compiled by gcc (GCC) 4.1.2 20080704 (Red Hat 4.1.2-46), 64-bit" "bytea_output";"escape" "client_encoding";"UNICODE" "lc_collate";"en_US.UTF-8" "lc_ctype";"en_US.UTF-8" "listen_addresses";"*" "log_destination";"stderr" "log_line_prefix";"%t " "logging_collector";"on" "max_connections";"100" "max_stack_depth";"2MB" "port";"5432" "server_encoding";"UTF8" "shared_buffers";"3GB" "temp_buffers";"64MB" "TimeZone";"Israel" "wal_buffers";"16MB" "work_mem";"20MB"
