If you are interested to know more about the technology (not the marketing hype) behind Exadata - the datawarehouse appliance from Oracle, I just discovered a treasure trove of information on this blog:
http://www.pythian.com/news/1267/interview-kevin-closson-on-the-oracle-exadata-storage-server#comment-350433
Kevin Closson, one the lead architects of the Exadata machine has been interviewed by Christo Kutovsky and Paul Paul Vallée of Phythian. Kevin, in his usual detailed style explains the innards of the beast, aided by the excellent leading questioning by Christo.
I believe this is best writing I have seen on Exadata - all good stuff, no fluff. Thank you, Kevin.
