Slony is one of the longest running and best known replication projects for PostgreSQL. It provides advanced features, though as a result is considered complex by many users.
Slony is also known as Slony-I because there were once plans for a Slony-II, though that doesn't exist (at least so far). Slony-I was first released as 1.0, though there is now a Version 2.0. So when we talk about Slony 2.0, we mean Slony-I Version 2.0.
If you haven't read the recipes on Replication Concepts and Replication best practice at the start of this chapter, please go and read them now. Replication is complex.
The first question to look at is whether to use Slony. Slony still has some advantages, even alongside streaming ...