[erlang-questions] MySQL cluster - MnesiaXXL(tm) :)

[Yariv Sadan]

Hi,

>
> It's more cautious to take the SourceForge way, and from there
> build forward - only there is a problem from transacting with
> two or three database systems instead of one.
> That is why i ask about TB sizes.... imagine in year one
> having say 10 to 20 thousand subscribed users, and then
> going to 5 to 10 million users, AND keeping the staff of
> 1 to 2 developers (we could take extra 200 employees,
> fork some 10 to 15MM$US on several thousand servers
> upfront ... THEN WHAT??? if it goes wrong... VC's will
> want to hang us :(

IMO, if you need to potentially store large data sets, and you might
need to run non-trivial queries on relational data, why take the risk
with Mnesia? There are very good open source SQL database engines that
have proven to be able to handle the task, whereas with Mnesia there's
some uncertainty. Plus, you can use ErlyDB to bridge the semantic gap
with SQL databases (although right now only MySQL is supported out of
the box) in a very natural way.

Btw, I'm not anti-Mnesia. I think Mnesia + MySQL is a great
combination, where Mnesia acts like a distributed cache for live
application data and MySQL holds long-term, high-volume data, that you
also may need to indexed for full text search (MySQL has a few
solutions in this area).

My 2c,

Regards,
Yariv