db-derby-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Arnaud Masson <amas...@gmail.com>
Subject Re: performance issue on 64 bit JVM
Date Fri, 03 Jun 2011 07:38:34 GMT
64-bit uses more memory,
so if your Xmx is too small,
the 64-bit version may have more GC overhead.

You can increase Xmx
or activate "compressed-pointers" to have a better memory usage.

(Also the max heap size must fit in physical memory, otherwise the swap
on disk could kill perfs.)


Le 03/06/2011 04:09, QA Wang Yang a écrit :
> Dear Derby
>
> Could you tell me how tuning the performance issue?
>
> This is running sample query to fetch data from Derby database
>
> On my dual-core XP x-32 laptop the Corporate Overview takes 406(ms).
> But we saw on the dual quad core it took 22973 (ms).
>
> I don't know why the performance became bad on my powerful machine.
>
> This is my test detail
>
> Query:
> select * from Customer;
> select * from product;
> select * from order;
> select * from Customer1;
>
> Dual-core XP SP3 32 bit,JDK1.6.0_25 32 bit,
> Dual quad core Windows 2008 64 bit, JDK1.6.0_25 64 bit,
>
>
> *32 bit Dual core
> Fetched record size: 1413
> Fetch record time: 250 (ms)
> Fetched record size 8
> Fetch record time: 15 (ms)
> Fetched record size: 6
> Fetch record time: 0 (ms)
> Fetched record size: 1413 records
> Fetch record time: 141 (ms)
> ====total 406 ms
>
> **64 bit Dual quad core
> Fetched record size: 1413
> Fetch record time: 11483 (ms)
> Fetched record size 8
> Fetch record time: 3 (ms)
> Fetched record size: 6
> Fetch record time: 4 (ms)
> Fetched record size: 1413
> Fetch record time: 11484 (ms)
> ====total 22973 ms
>
> Thanks a lot
>
>
>
> Wangyang
> QA Group
> Jinfonet Software, Inc.
>
> www.jinfonet.com
> 2nd floor on the east of BEC Theatre
> 135 Xi Zhi Men Wai Street, Xicheng District Beijing, China 100044
> yang.wang@support.jinfonet.com
> 86-10-68316633
>
> JReport
> Embedded Reporting for Java Applications
>
>
>


Mime
View raw message