So it does.
I used
pg_output = new BufferedOutputStream(new OutputStream() {public void write(int b) throws IOException {}}, 8192);
And confirm that I get similar slowdown for my code, and much faster operation for your code.
The only thing I can think might be going on with your code is the hotspot compiler recognising the bytecode pattern in
use,and using the fastest method it knows of filling that byte array.
SendInteger2 behaves the same surprising way.
Regards,
Stephen.
-----Original Message-----
From: Kris Jurka [mailto:books@ejurka.com]
Sent: Tuesday, 27 February 2007 5:24 p.m.
To: Stephen Denne
Cc: pgsql-jdbc@postgresql.org
Subject: Re: [JDBC] Minor performance improvements
On Tue, 27 Feb 2007, Stephen Denne wrote:
> I'm sad to say that I have not created any micro-benchmark tests, and
> unfortunately the improvements are very minor, and far overshadowed by
> the variability I get from my system.
>
I've created the attached test which tests the original code (Orig), your code (Two), and my suggestion of an int4buf
(Three)and got the following surprising results:
jurka@tony:~/pg/jdbc/projects/perf/micro$ java -classpath . Tester Orig | sort -n
11335
11370
11468
11484
11487
jurka@tony:~/pg/jdbc/projects/perf/micro$ java -classpath . Tester Two | sort -n
12472
12476
12489
12492
12619
jurka@tony:~/pg/jdbc/projects/perf/micro$ java -classpath . Tester Three | sort -n
4259
4562
4564
4611
4689
This shows your code is actually slower than the original code, although I have no idea why that could be. It shows
theint4buf idea as a clear winner. I'm a little suspicious of the whole test because of your numbers going up. Could
youtake a look at this and possibly confirm the results?
I'm not sure if windows has an equivalent to /dev/null, but I wanted to avoid any impact of disk io.
Kris Jurka
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