Binary package “libpq5” in ubuntu precise

PostgreSQL C client library

 libpq is a C library that enables user programs to communicate with
 the PostgreSQL database server. The server can be on another machine
 and accessed through TCP/IP. This version of libpq is compatible
 with servers from PostgreSQL 8.2 or later.
 This package contains the run-time library, needed by packages using
 PostgreSQL is an object-relational SQL database management system.