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Re: jdbc driver performance TODO

From: "Strong, David" <david(dot)strong(at)unisys(dot)com>
To: "Simon Riggs" <simon(at)2ndquadrant(dot)com>,<pgsql-jdbc(at)postgresql(dot)org>
Subject: Re: jdbc driver performance TODO
Date: 2006-10-31 15:47:58
Message-ID: B6419AF36AC8524082E1BC17DA2506E80329F7D5@USMV-EXCH2.na.uis.unisys.com (view raw or flat)
Thread:
Lists: pgsql-jdbc
Simon,

Here's an observation about the JDBC driver, but I'm not sure if it's
practical to implement. After preparing a statement, the driver still
sends out a describe message either via the sendDescribeStatement () or
(most likely) the sendDescribePortal () method calls in
org.postgresql.core.v3.QueryExecutorImpl. However, as the statement has
been prepared, it's unlikely to change and so the results of the
sendDescribeXXX () could be requested once and then cached with the
prepared statement.

Of course, if any tables referenced by the query where changed, the
prepared statement would be caching the original structure. Although,
I'm not sure how much of a problem this would be as changing a table's
data types etc. might cause code to break anyway.

I don't see a direct way to turn off the metadata, perhaps I'm missing
something?

David



-----Original Message-----
From: pgsql-jdbc-owner(at)postgresql(dot)org
[mailto:pgsql-jdbc-owner(at)postgresql(dot)org] On Behalf Of Simon Riggs
Sent: Friday, October 27, 2006 3:58 PM
To: pgsql-jdbc(at)postgresql(dot)org
Subject: [JDBC] jdbc driver performance TODO

I'm interested in updating the performance TODO list for the jdbc
driver. I want to refresh the TODO list with any new items people are
aware of, plus make sure each item has a link to an agreed design if one
exists.

Forgive me for the observation, but the current list does seem to be a
little out of date:
- Add statement pooling to take advantage of server prepared statements.
- Allow scrollable ResultSets to not fetch all results in one batch.
- Allow refcursor ResultSets to not fetch all results in one batch.
- Allow binary data transfers for all datatypes not just bytea. 

Could I shake the tree for any new performance suggestions? Or maybe not
new exactly, but just not listed. Lots of detail please....

-- 
  Simon Riggs             
  EnterpriseDB   http://www.enterprisedb.com



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