On Wednesday 19 March 2003 04:33 am, you wrote:
> Dave Cramer <Dave@micro-automation.net> writes:
> > On Tue, 2003-03-18 at 19:00, Hiroshi Inoue wrote:
> >> ODBC(maybe JDBC also) has cross-transaction result sets
> >> (rather than cursors) since long by simply holding all
> >> results for a query at client side.
> >
> > JDBC is running into problems with this. Large queries cause out of
> > memory exceptions.
>
> Cursors implemented as Neil suggests would cause out-of-disk exceptions.
> The limit is presumably further away than out-of-memory, but not any the
> less real. I'm concerned about this because, in my mind, one of the
> principal uses of cursors is to deal with too-huge-to-materialize result
> sets.
>
> Still, given that we have no prospect of a "real" solution any time
> soon, a limited solution might be a reasonable thing to offer for now.
>
We have got more disk space than internal memory.
Similar argument would be valid for swap in operating systems,
but all operating systems have got swap and large results sets use swap, probably.
'Out of disk' is small problem - we can add more disk easy.
Cursors out of a transaction are great features - the most important for clients in
Java, but for other clients.
regards
Haris Peco