are Mnesia tables immutable?

[Andrew Lentvorski]

Yariv Sadan wrote:

> To the outside observer, it seems like Google's lightbulb hasn't gone
> off yet when it comes to functional languages :)

Careful.

Google for MapReduce.  http://labs.google.com/papers/mapreduce.html

And, BTW, Google hired Peter Norvig.  Take a look at norvig.com.

> So, either this is an advantage to Google's competitors who *do* use
> functional languages -- especially Erlang, the #1 choice for buidling
> scalable, concurrent, fault-tolert, distributed systems, which is
> Google's bread and butter -- or Google is shy about this fact on its
> website :)

Google is very different from most distributed systems.  They don't need 
to be particularly reliable, correct, or accurate and long as they don't 
return anything that is particularly *wrong*.

Again, see MapReduce.  With MapReduce, they either rerun the 
computation, or, more likely, just don't worry about the lost results 
since they have so many other ones anyhow.

> Yes, unicode does make things different. In Java, all strings are
> unicode (like Erlang), but there isn't the extra 32 bit overhead per
> characters for building the linked list.

Is that strictly true?  It is for String, but String is immutable.  What 
about StringBuilder or StringBuffer?  Those will almost certainly have 
some overhead.

-a