What's the data flow between Pgpool, Postgresql and client
Pgpool is a kind of a layer between client and postgresql. Pgpool receive a query from client and ask Postgresql for data. Postgresql answers to Pgpool and pgpool send data to client like on the picture below. There is not direct connection between client and Postgres when you use Pgpool to connect to database. By the way Pgpool provides connection pooling, replication, load balance, connection limits and paralell query so it's quite nice to use with PGSQL



Manual: http://www.pgpool.net/docs/latest/pgpool-en.html