From: | Peter Mount <peter(at)retep(dot)org(dot)uk> |
---|---|
To: | Gunnar R|nning <gunnar(at)candleweb(dot)no> |
Cc: | kientzle(at)acm(dot)org, PostgreSQL general mailing list <pgsql-general(at)postgresql(dot)org>, "Keith L(dot) Musser" <kmusser(at)idisys(dot)com> |
Subject: | Re: Re: JDBC Performance |
Date: | 2000-10-03 11:06:19 |
Message-ID: | Pine.LNX.4.21.0010031158450.420-100000@maidast.demon.co.uk |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-general |
On 2 Oct 2000, Gunnar R|nning wrote:
> Peter Mount <peter(at)retep(dot)org(dot)uk> writes:
>
> >
> > For JDBC2, I'm planning (may get done for 7.1) an alternate ResultSet
> > class that uses cursors. This would speed things up as the entire
> > resultset isn't received in one go. That's the biggest bottleneck of them
> > all.
> >
>
> I would think this depends on the queries you execute. Is it any overhead on
> the backend side related to retrieving results through the use of
> cursors(ignoring the extra bytes sent) ?
Which is why it's an alternate class, not a replacement. The existing one
is for general use, but you can define the cursor name, so if you do for a
particular Statement object, then the ResultSet's from it would use that
cursor.
> If you only use a fragment of the data in the result set this method would
> of course be faster, but in other situations I'm concerned that you will
> only add overhead to the ResulSet.next() method(with familiy). But you
> mentioned alternate implementation, so that would probably mean that the
> user can choose the appropriate implementation for his application ?
Yes. The related methods are:
Statement.setCursorName(String name)
Statement.setFetchDirection(int direction)
Statement.setFetchSize(int rows)
The Statement.getResultSetType() method returns TYPE_FORWARD_ONLY for the
existing class, and TYPE_SCROLL_INSENSITIVE for the new one.
Peter
--
Peter T Mount peter(at)retep(dot)org(dot)uk http://www.retep.org.uk
PostgreSQL JDBC Driver http://www.retep.org.uk/postgres/
Java PDF Generator http://www.retep.org.uk/pdf/
From | Date | Subject | |
---|---|---|---|
Next Message | Peter Mount | 2000-10-03 11:07:34 | Re: Re: JDBC Performance |
Previous Message | Peter Mount | 2000-10-03 10:57:37 | Re: Re: JDBC Performance |