Did the last Google Dance come with update BART or Fritz?

Matt's answer:

Today’s question comes from Zurich. Gary Tamas asks a critical question. He asks, “According to ‘In the Plex,’ the last Google Dance and everflux switch came with Update ‘Bart,’ but in an earlier post, you said it was ‘Fritz’. Did the last Google Dance and switch to everflux come with Bart or Fritz?” Whew! OK, good question. And it is critical that we nail down all these last little bits of ancient search engine history, so I’m glad you asked. So Bart was the internal code name. It was actually, if I remember correctly, named after a particular salesperson, who was especially fresh. So if somebody comes to a Halloween party dressed as Barry Bondage, that’s pretty fresh, right? So named after a salesperson internally, Bart. It was known as Fritz externally, because whenever the Google Dance would happen, it would happen about once a month. And basically, you’d have several data centers. And each night, we would take one data center out of the rotation, and we would put new data on it. So for about a week, we were swapping now old data versus new data. And so for that week, you’d have the Google Dance, because you’d hit either old data centers or new data centers. So once a month, people would look for the Google Dance to happen. They would name them alphabetically like hurricanes. You start with A early in the year and then B the month after that. And so summer, which was F, you’d have gotten to Fritz. So they called it Update Fritz. And I remember, Fritz lasted all the way through the summer of, I believe, 2003, because it was really Everflux. That is, it was changing to an incremental update system. So rather than a batch system that would update once per month, it was, OK, we’ll update a certain percentage of our index every night, and so the index was always changing. So internally, that system to have very fresh results was called Bart. Externally, people called it Update Fritz. So I hope that explains the difference between those two names.

by Matt Cutts - Google's Head of Search Quality Team

Original video: