Re: Concurrency in an RDB

NENASHI, Tegiri wrote:
> "David" <davidbl_at_iinet.net.au> wrote in
> news:1166574353.111425.137600_at_f1g2000cwa.googlegroups.com:
>
> >
> > NENASHI, Tegiri wrote:
>
>
> >> It is impossible to see what you mean because you have not responded
> >> to:
> >> what the compile of transaction is. Why compile(T1+T2) is diffrent
> >> of
> >> compile(T1), compile(T2) ? What is the compile ?
> >
> > I brought up this example to show that complex integrity constraints
> > can lead to poor performance. There is a DB of source code with an
> > integrity constraint that it must compile successfully at all times.
> > This would normally require a recompile of the source code to validate
> > every mutative transaction (a failure to compile would cause the
> > transaction to abort). Sampo suggested that transactions could be
> > validated in batches (ie accumulated) so the recompile was performed
> > less often. I pointed out that if the error rate is high then
> > batching won't help at all.
>
> You have not showed this because we do not know a) what the compile is;
> b) why the compile in batches is different of the individual compile --
> why, when in the batch, one neeeds to compile more ? Your description
> is very general and non-understandable. What is this compile ? Is it
> that you cannot give an example of compile ? If this is so, then you
> are just playing with words.

Ok I'll be more specific. The DB emulates a file system and contains C++ source code. A transaction involves atomically applied edits to one or more "files". A "compile" means compilation of all the source code into an executable. Now please re-read my previous posts!

Cheers,
David Received on Wed Dec 20 2006 - 06:33:44 CET