pgbouncer (Lightweight connection pooler for PostgreSQL)

pgbouncer is a PostgreSQL connection pooler. Any target application
can be connected to pgbouncer as if it were a PostgreSQL server,
and pgbouncer will create a connection to the actual server, or it
will reuse one of its existing connections.

The aim of pgbouncer is to lower the performance impact of opening
new connections to PostgreSQL.
