I thought this article was really good at explaining the differences of
relational DBs and Key/Value stores and some other models coming down
the pipe (i.e. the new buzzword "Cloud Computing").
http://www.readwriteweb.com/archives/is_the_relational_database_doomed.php
Will mySQL be adaptable to plug in these other types of engines (as we
do for InnoDB, MYISM, Falcon, Maria, etc.)
Page 3 does mention Drizzle, but that's also (as they said) a
counter-approach to key/value stores.
These new types still use a key so it would be awesome if you could
seamlessly reference (foreign) keys in these new domains/"tables" along
with your INNODB keys, etc. "Cross-engine compatibility" if you will.
...and on a semi-related topic, I've just learned of this mysql engine:
http://www.tokutek.com and hadn't heard a peep about it on this list
before?!
iiBench - Insertions Only:
http://blogs.tokutek.com/tokuview/iibench_fractal_tree_results/
iiBench - with Deletions:
http://blogs.tokutek.com/tokuview/iibench_with_deletes/