Archive for October, 2008

Switch workspace on command line

Sometimes, it’s nice to change the current windowmanager workspace on command line, for example if you desire to start a application exactly HERE or THERE.

For KDE you may want to do it with “kstart”. But a tool like kstart might not be available for your windowmanager, so have a look at “wmctrl” as well: http://www.sweb.cz/tripie/utils/wmctrl/.

Have fun
Usn



Oracle 10g Data warehouse ORION benchmark, size 20TB, 1200MB per second

During the last days, I have had the opportunity to test and benchmark a data warehousing hardware, that’s really fast for its money. It’s not suitable for real/available production, since it depends on disk striping over a bunch of components, but I considered it as a good way to push the limits a bit.

Result: A throughput of about 1200MB/s and nearly 1200 iops. Period. You may quickly want to see detailed results on the bottom of the page, but for fully understanding of the results look up the setup as well.
Read more…



Attended “Reactive Performance Management” with Craig Shallahamer

Monday and today (Tuesday) I attended a 2-days Oracle University class with Craig Shallahamer from OraPub, taking place in Munich.

Craig Challahamer Munich

Honestly, I have had no expectations at all, so there has been nothing to be crestfallen or to be fulfilled. I just was looking forward to the one or other hint how to find the reason of slow databases – the class tilte looked promising in this context. But lets report in chronological order. Read more…


By usn in Oracle  .::. Read Comment (1)

memlock config for Debian Lenny

Hi,

today I tried to start Oracle XE with parameters “pre_paged_sga=true” and “lock_sga=true” on my Debian Lenny toybox. But Lenny has had a rather strict and really sticky value for the user’s maximum amount of pinned memory (ulimit -l) value: 32 (kb).

First attempt, change /etc/security/limits.conf:

oracle                  -       memlock         1073741824

Result: Nothing, “ulimit -l” as user newly logged-in user oracle still shows “32″.

After researching for a while, it became clear that there has to be something fishy with using the “su” command, the “ulimit -a” output has been different in several points, compared with a native console login. Debian project philosophy “make it hard” struck again: Look up /etc/pam.d/su, and find, that there is a block:

# Sets up user limits, please uncomment and read /etc/security/limits.conf
# to enable this functionality.
# (Replaces the use of /etc/limits in old login)
# session    required   pam_limits.so

Needless to say, it worked after uncommenting the last line. And, keep in mind, it depends on a well configured limits.conf. But why, for sake, do I have to change that for my hobby distribution?

With pain in the backside and a bit frustration,
Usn




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