I think this http://www.javaworld.com/javaworld/jw-02-2001/jw-0209-double.html
applies to your implementation ?
On Thu, Feb 9, 2012 at 7:01 PM, Steven Schlansker <steven(at)likeness(dot)com> wrote:
> There is a bug report and associated mailing list thread
> [JDBC] [BUGS] BUG #6293: JDBC driver performance, dated Nov 15 2011
>>>> The following bug has been logged online:
>>>> Bug reference: 6293
>>>> PostgreSQL version: 9.1
>>>> Description: JDBC driver performance
>>> The 9.1 JDBC driver was changed to try and fetch all metadata for the
>>> entire resultset in one query instead of potentially issuing multiple
>>> queries for each column. So this change was supposed to improve things.
>>> Looking at the code, the caching pattern has changed slightly, so now it's
>>> important to hold onto the same ResultSetMetaData instance. That is you
>>> need to do:
> I have a proposed fix available as a pull request on GitHub. The commit itself is here:
> and the pull request complete with an in-progress discussion is here:
> I requested guidance on the mailing list last week on the best way to approach this problem,
> but there were no responses, so I have changed the ResultSet to cache the MetaData instances.
> As best as I can tell the MetaData is immutable, so hopefully there will be no ill effects from
> caching instances.
> I saw some discussion about licensing re: GitHub on the mailing list the other day, so to be
> perfectly clear I am releasing this code to the pgsql-jdbc project under whatever terms they
> so choose, or the public domain if that is the appropriate choice.
> I hope this will be an example of how moving to GitHub pull requests can be a positive change :-)
> I believe this fixes the referenced bug, and I've asked the original submitter to test out my change
> to see if it fixes it for him.
> Steven Schlansker
> Ness Computing
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|Next:||From: Steven Schlansker||Date: 2012-02-10 03:32:26|
|Subject: Re: Patch to fix bug #6293 - regression in driver performance with regards to ResultSetMetaData-heavy workloads|
|Previous:||From: Dave Cramer||Date: 2012-02-10 00:50:13|
|Subject: Fwd: [pgjdbc] Change Jdbc4ResultSet to cache Jdbc4ResultSetMetaData