The date on some of those posts in interesting. 2009 is quite a while ago now, and I'd suggest that columnar datastores haven't exactly taken over. Some implementations have made some progress (eg Cassandra), but OTOH many non-traditional datastores have added traditional-database like features (eg, Facebook's SQL front end on their NoSQL system), and traditional databases have added NoSQL features too.
Stonebraker is a very smart person but he's also not shy about promoting his own companies/research. You generally get a well-informed but very opinionated take on things from him.
VoltDB, for example, is good for certain complex workloads over large but not-too-large data sets. For a lot of situations it isn't really an alternative to memcache+MySQL or a NoSQL solution.
If I may drool a little, you guys represent the heart of Hacker News. Insightful summary, mentioning that somewhere somebody gave such a talk. As I was reading the first comment I was silently cheering for "a librarian's follow-up", and there it was!
The log mechanism Prof. Stonebraker prefers, command logging vs ARIES, almost all newer data stores use command logging w/checkpoints (i.e., redis, mongo) and ship changes to other nodes similarly.
After running a large production redis environment, having a large redo log makes startup/recovery painful. I'm not convinced command logging is the most efficient in all scenarios especially when doing counters where the command is more verbose than the resulting change.
