Where, and in what context did you hear that? What I saw of the announcement (the blog post and a small part of the presentation) didn't seem very technical. Was this in response to a question someone asked or did someone take time at the event to talk infrastructure?
>In order to make this work, “we had to completely rebuild >the infrastructure that this system is build on,” Bosworth >noted. People are aware of Facebook’s Cassandra system, but >now they’ve built something new called hBase (working >alongside the open source community again).
