Re: cursors outside transactions

Bruce Momjian wrote:
>
> Tom Lane wrote:
> > Dave Cramer <Dave(at)micro-automation(dot)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.
>
> I don't see how you can class out of memory in the same likelyhood as
> out of disk --- sure they are both real possible failures, but clearly
> the latter is more rare and giving folks backing store for large result
> sets is a big win in my book.

Other than the out of disk/memory problem, there 's
another problem. What I expect of cursors is the
constant response time while handling them.

regards,
Hiroshi Inoue
http://www.geocities.jp/inocchichichi/psqlodbc/