Re: Interfaces that support cursors

Quoting Doug McNaught <doug@mcnaught.org>:

> Network Administrator <netadmin@vcsn.com> writes:
>
> > Ok, I did see the autocommit flag setting in DBD:Pg when I starting
> > reading up on the DBI/DBD interfacing methods so I guess I could
> > recode for that.  However, how do you "maintain" the current
> > transaction open if your script is writing pages to the web.  Even
> > in mod_perl I think that there is a commit after the script ends,
> > no?
>
> Oh, right--I didn't get that bit of your problem.
>
> I think the conventional wisdom on this is that keeping transactions
> open across web page deliveries is a Bad Idea.  If you're just doing
> the standard "show N records per page" thing, you can use LIMIT and
> OFFSET on your SELECT call.  This is going to be slower thn using a
> transaction (because you're re-executing the query for every page) but
> is fairly simple.
>
> If you really want to have a DB transaction that covers multiple page
> views, you need some kind of persistent application server rather than
> CGI scripts, so you can keep open connections and application state
> around.
>
> -Doug
>

Ahhh, I didn't know about the offset part of limit.  Sounds like winner- might
not be that bad since the query optimizer takes that into account when planning.

Thanks Doug.

--
Keith C. Perry
Director of Networks & Applications
VCSN, Inc.
http://vcsn.com

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