Lawrence Terrill was presenting an introduction to the RETE algorithm at the October Rules Fest 2009 in Dallas today.

To those who don’t know what the RETE algorithm, it is basically what kicked off the Inference Rules Engine world when it was first developped in 1979 by Charles Forgy. So this is a very good way to kick off a technical conference on Business Rules. The algorithm has been improved upon since the original but this was still the original work that was done.

Some of the original purpose and assumptions of the algorithm were:

• Improve the speed of pattern matching
• To offer support for rule-chaining (not simply sequential)
• Have performance at the cost of using more memory

Some of the basics of Rete:

• Two parts to the network
  • Alpha network, which is a discrimination network
  • Beta network, which is the joins between the attributes of the Objects

Because of the technical nature of the presentation I won’t go any further on that topic here. You just have to attend a presentation like that to get something out of it.

Overall though, a very interesting introduction to the RETE algorithm.