Photo by Prachya Singhto
Pgpool-II started its history as a connection pooler
The word "pool" in Pgpool-II had traditionally meant "connection pooling". Actually the software was born as a connection pooling software in 2003. However after 18 years passed Pgpool-II is not only a connection pooling software anymore. Rather, the connection pooling feature is just one of rich features of Pgpool-II.
More feature has been added to Pgpool-II
In 2004 native replication feature (statement based replication) was added. In 2010 PostgreSQL's streaming replication can be managed. In 2012 Watchdog, a high availability feature for Pgpool-II itself, has been added. Moreover automatic failover and load balancing are possible.
Now "pool" means "pool of PostgreSQL"
With all these feature now Pgpool-II is effectively a PostgreSQL cluster management software. So I decided to redefine the meaning of "pool" to be "pool of PostgreSQL servers". In this direction I have updated the intro chapter of PostgreSQL manual for the next release (Pgpool-II 4.3).
Pgpool-II manages a pool of PostgreSQL servers to achieve some features that are not available with single PostgreSQL installation.An HTML compiled version of the chapter can be viewed here.
I hope this change gives people more appropriate view of this software.