Rambl(og)ing

You're missing out!

2010-03-11T06:45:00.003-08:00

You're missing out!
Originally uploaded by jmourik

Jan (sent from my iPhone)

Tanel Poder at the Hotsos Symposium

2010-03-11T06:45:00.001-08:00

Tanel Poder at the Hotsos Symposium
Originally uploaded by jmourik

Jan (sent from my iPhone)

Airco ventilation

2009-07-15T19:48:00.001-07:00

Airco ventilation
Originally uploaded by jmourik

One thing I can't stand, the air conditioning blowing on me when I'm
in bed! So I made some changes...

Jan

Norfolk, VA

2009-06-24T17:41:00.001-07:00

Norfolk, VA
Originally uploaded by jmourik

Jan

Norfolk, VA

2009-06-24T14:18:00.001-07:00

Norfolk, VA
Originally uploaded by jmourik

Jan

My favorite seat :-(

2009-06-22T08:26:00.001-07:00

My favorite seat :-(
Originally uploaded by jmourik

Last row in the plane, seat 13B, right next to the lavatory...

Luckily it was a short flight and nobody made use of it!

Nissan Sentra

2009-06-09T16:13:00.001-07:00

Nissan Versa
Originally uploaded by jmourik

My rental car this week is a Nissan Sentra. I'm impressed! It drives like a bigger car, minus some of the power. But that will translate into a better mpg. It's a very smooth ride, especially for a small car. As smooth as anything I'd say. Even smoother than my I30!
if you're in the market for a small car, make sure to try this one out!

Alaska

2009-05-31T21:39:00.001-07:00

Alaska
Originally uploaded by jmourik

Jan

Sitka, ak

2009-05-26T12:25:00.001-07:00

Sitka, ak
Originally uploaded by jmourik

Jan

Residence Inn

2009-04-21T18:35:00.001-07:00

Residence Inn
Originally uploaded by jmourik

Virtual Machines II

2009-03-30T12:34:00.000-07:00

The FreeNas option I talked about in my previous post about virtual machines seemed like a fun thing to try. So I downloaded a FreeNas VMware image and added it to my inventory. After setting it up and adding a 10Gb disk, I wanted to auto mount it in my Linux VM. Took me a bit of googling, but I got it done:

> mkdir /u01/freenas_10gb

Then I added this line to /etc/fstab (see http://nfs.sourceforge.net/nfs-howto/ar01s04.html ):

10.10.10.10:/mnt/FreeNas_10Gb /u01/freenas_10gb nfs rw 0 0

where 10.10.10.10 is the ip address of my FreeNas server (VM). after reboot I was happy to see:

[root@rac1 ~]# df -k
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/mapper/VolGroup00-LogVol00 16067440 7416848 7826604 49% /
/dev/sda1 147764 11940 128195 9% /boot
tmpfs 1037800 0 1037800 0% /dev/shm
10.10.10.10:/mnt/FreeNas_10Gb 10154144 1920 9339904 1% /u01/freenas_10gb

[root@rac1 ~]# ls /u01/freenas_10gb
FreeNAS-SUG.pdf

Nice!

Virtual Machines

2009-03-28T15:37:00.000-07:00

Lately I've been playing with virtual machines a bit. I've installed VMware Server on both my laptop and desktop, and VirtualBox just on my laptop. Both these products are easy to use, and haven't given me any problems with the host OS so far. I'm running XP on the laptop, Vista 64bit on the desktop. I must admit I favor VirtualBox a bit though, mainly because it seems to work also when I'm not on the network. In that case VMware refuses to start my virtual machines. But maybe that's also my fault. Also VirtualBox seems to be a bit faster on my laptop. Also, the shared folder feature in VirtualBox is a big plus to me, this is something VMware doesn't want to give us for free. The OS installed in the VMs is Oracle Enterprise Linux.
I did some benchmarking this week using some old unix benchmark tool, Unixbench . It was fast to download and easy to run, you see. These are the results:

As you can see, VirtualBox ran 15~20% faster on my laptop. Also, hardware virtualization did help this benchmark. Quite a bit!

The drawback of VirtualBox is that it doesn't support shared disks. I'm setting up a virtual Oracle RAC cluster on my desktop, so the two VMs need to be able to share disks. So that's the main reason I'm using VMware. I guess I could use VirtualBox and add a third VM running FreeNAS. Hmmm, that might be fun! After all, I do have a quad core :-)

One thing I noticed on my laptop, with hardware virtualization enabled (in the bios), XP hangs when I try to put it into hibernation. This works fine when I turn it off.

Btw, I just ran unixbench in both my VMs at the same time, and the final scores were 224.2 and 228.0! Not bad!

Bayou Bend

2009-03-22T14:47:00.001-07:00

Bayou Bend
Originally uploaded by jmourik

Symposium time!

2009-03-09T12:31:00.001-07:00

Symposium time!
Originally uploaded by jmourik

2009-03-01T09:53:00.000-08:00

kuhf had another episode of This American Life this morning on the banking crises. This one about Bad Banks. The podcast is available for free for a week, so get it while you can :-)
Scary stuff though, really makes you wonder about what to do about some of these big banks like Bank of America and Citigroup. Should we keep them going, or stop pretending and take them over already?
See also the Planet Money and The Baseline Scenario blogs...

C-Span

2009-02-26T12:58:00.000-08:00

Who knew C-Span could be so much fun?
Future of the Internet - Twitter / Evan Williams

Multimedia message

2009-01-28T10:10:00.001-08:00

Multimedia message
Originally uploaded by jmourik

Multimedia message

2009-01-25T16:31:00.001-08:00

Multimedia message
Originally uploaded by jmourik

Multimedia message

2009-01-25T12:30:00.001-08:00

Multimedia message
Originally uploaded by jmourik

Multimedia message

2009-01-25T11:55:00.001-08:00

Multimedia message
Originally uploaded by jmourik

Thai Place restaurant

2008-12-17T17:44:00.001-08:00

Thai Place restaurant
Originally uploaded by jmourik

Colder

2008-12-15T08:01:00.001-08:00

Colder
Originally uploaded by jmourik

Cold!

2008-12-14T15:59:00.001-08:00

Cold!
Originally uploaded by jmourik

Calgary

2008-12-13T10:01:00.001-08:00

Calgary
Originally uploaded by jmourik

Porsche show in Charlotte

2008-06-29T09:18:00.001-07:00

Porsche show in Charlotte
Originally uploaded by jmourik

Flashback database impact

2008-06-26T08:24:00.000-07:00

Ran into this interesting problem not too long ago. A procedure doing an insert and a merge ran much slower in one environment compared to another similar environment. After tracing in the slow environment and profiling the trace, this came up:

That much time spend on "db file sequential read" for a straightforward "insert into ... values (....)"? Weird...
A bit more investigation showed that lots of those waits were for the undo tablespace:
p5skew --name="db file sequential read" --group=$p1 xxxxx_ora_13766882.trc

So what are those files?

select file_id, tablespace_name from dba_data_files where file_id in (116,179,124,2,115,187,244);


FILE_ID TABLESPACE_NAME
244     UNDO2
179     xxxxx_DAT_IOT
187     UNDO2
124     UNDO2
116     UNDO2
115     UNDO2
2       UNDO2

So mostly undo (83.6%)! Why?

Then I started thinking about one major difference between the two databases, the one with the slow performance had flashback database enabled. A quick search on Metalink gave me Note:565535.1 "Flashback Database Best Practices & Performance". This note tells us that "Insert intensive batch jobs may be impacted by as much as 30% with flashback database on."
So we disabled flashback database, reran the proc and performance improved dramatically. So Oracle was absolutely telling us the truth in that note. So beware of this in Oracle 10g, when using this very cool feature!

PS. Screenshots are from Hotsos profiler output.

Kindle

2008-06-23T12:39:00.000-07:00

From looking at this page you might notice I've been having way too much fun with my Kindle and book sites Shelfari and LibraryThing. I got my Kindle a week ago, after long deliberation. Actually, I ordered one last December, but canceled after a month because they weren't in stock. Now I finally ordered again, and so far I'm loving it!
The pics show the size of the Kindle, not too big, easy to hold.
One lesson I learned so far: do NOT leave your Kindle connected to your PC through the USB cable, it will totally drain the Kindle's battery! Ouch! I figured it would work like my Zune, when connected it charges. But no, not the Kindle...
One of my favorite features so far is the build-in dictionary. Mark a line and click lookup, and the Kindle will search the New Oxford American Dictionary for the words. Very nice indeed!

Paperback vs. Kindle vs. CD:

Kindle side view compared to a paperback:

Hyatt Place: Nice!

2008-03-09T19:57:00.001-07:00

Hyatt Place: Nice!
Originally uploaded by jmourik

Tom Kyte at Hotsos

2008-03-06T06:34:00.001-08:00

Tom Kyte at Hotsos
Originally uploaded by jmourik

Snow in Dallas

2008-03-03T19:23:00.001-08:00

Snow in Dallas
Originally uploaded by jmourik

Hotsos

2008-03-03T13:30:00.001-08:00

Hotsos
Originally uploaded by jmourik

Galveston

2008-02-25T12:10:00.001-08:00

Galveston
Originally uploaded by jmourik

Jamaica

2008-02-25T12:06:00.001-08:00

Jamaica
Originally uploaded by jmourik