Re: VoltDB

On 2010-05-26 18:27, Jon Asher wrote:
> Well it's an in-memory db so it's fast. Big surprise. Think of
> memcache for the cloud with SQL support.

My "perpetual motion" snark was aimed at the way the web site implies
that you get all the wonderfulness without giving up anything. The web
site is actually surprisingly coy about exactly how it works unless you
"register", and the whole thing has been deliberately shrouded in
mystery from it's inception. (Epic fail - NEVER make people who might
want your product "register" before they are allowed to know any details
of it!)

I am not saying that H-store/VoltDB is a bad product or bad concept
within its niche; I am just very unimpressed by the way the web site
appears to engage in the sleazy overselling techniques of big
corporations. That is a pattern that seems to have evolved as the
project became more visible over the past year or so. I smell a weasel
at work! :-)

Some more thorough searching elsewhere reveals that this is far from a
general-purpose RDBMS, and even the SQL support is hedged about with
rather draconian limitations and caveats (you weren't expecting to be
able to issue SQL queries via JDBC, were you?) I'd go so far as to say
that the SQL support might be more about marketing than it is about
utility, since all db access has to be via specially structured Java
classes anyhow.

In short, if you can fit your application into its rather narrow
world-view, it can be spectacularly fast, but if your application
evolves in the "wrong"direction, most of the benefits will likely
evaporate. Personally, I don't like laying myself open to catastrophic
performance degradations and/or inability to deliver when my users'
requirements change unexpectedly - I'd rather it was slow to begin with
than blazing fast for a year, then slow, because the latter gets you
fired at the end of the year. That said, there are some very successful
applications that use non-RDBMS environments that have the same
characteristic, and people have managed to make those work (and retain
their jobs).

--
Peter Headland