tag:blogger.com,1999:blog-103987162009-11-11T11:27:22.336+01:00OraPerfhttp://www.blogger.com/profile/01936794393501829574noreply@blogger.comBlogger8125tag:blogger.com,1999:blog-10398716.post-67941444212428605482006-09-30T17:32:00.000+02:002006-09-30T17:39:39.492+02:00

This is a picture taken by the Hubble telescope before it broke down. NASA is desperately trying to repair it. But this last picture shows the surface of URANUS. It has great detail. More detail will follow in a later blog.

OraPerfhttp://www.blogger.com/profile/01936794393501829574noreply@blogger.com12tag:blogger.com,1999:blog-10398716.post-86835853927583210212006-09-13T10:46:00.000+02:002006-09-13T11:01:27.209+02:00

On Sunday september 10th I flew to Scotland to present at the Oracle Usergroup in Glasgow. I was aware of the new rules with carry on lugguage (well I thought I knew) and handed my carry on back over at the checkin counter and just double checked to see if the rules were still very strict. Turns out I was allowed to bring the bag on board, however it was too heavy and that is why it had to be

OraPerfhttp://www.blogger.com/profile/01936794393501829574noreply@blogger.com25tag:blogger.com,1999:blog-10398716.post-84509242655735161342006-08-24T23:47:00.000+02:002006-08-24T23:59:20.470+02:00

It has been a hectic week. My wife got a job and is now working 32 hours a week, that took less then 2 weeks, and on her first day I was in Denmark with my good friend Mogens Norgaard from Miracle Denmark. He said to me that I should come and be part of the Miracle Director Training Program. Last week it was Thomas Presslie from Miracle Scotland who got the same treatment.The training program is

OraPerfhttp://www.blogger.com/profile/01936794393501829574noreply@blogger.com17tag:blogger.com,1999:blog-10398716.post-90857561301471803922006-08-21T09:16:00.000+02:002006-08-21T10:06:17.088+02:00

It took a while for a new post to show up on this blog, but I am back. The reason for that is that I quit my comfy job at Symantec and will startup Miracle Benelux together with Mogens Norgaard. So now I can post what ever I want without having some corporate lawyer looking over my shoulder.So why quit? I tried to make a difference for close to 5 years and after the 3rd reorg in the last 3 years

OraPerfhttp://www.blogger.com/profile/01936794393501829574noreply@blogger.com77tag:blogger.com,1999:blog-10398716.post-1118912661330045082005-06-16T10:52:00.000+02:002005-06-17T23:38:07.130+02:00

How does one show the impact of long Seek times on the total I/O response time? I took a maxtor 200GB firewire harddrive (for my linux RAC test installation) and reconfigured the hard drive to have partitions of 2 GB on the outer tracks and inner tracks (accomplished with fdisk).Disk /dev/sda: 203.9 GB, 203927060480 bytes255 heads, 63 sectors/track, 24792 cylindersUnits = cylinders of 16065 * 512

OraPerfhttp://www.blogger.com/profile/01936794393501829574noreply@blogger.com109tag:blogger.com,1999:blog-10398716.post-1118562240368456192005-06-12T09:32:00.000+02:002005-06-12T09:44:56.420+02:00

There is a thread on AskTom about where to place data on the disk. The question is why one should place data on the outside of the disk and if that helps performance. I just like to add my view on that discussion. The number of physical I/Os per Disk is limited by the (full/average) seek time. The seek time is the biggest component of the I/O time (with normal Oracle blocksize). The Full Seek

OraPerfhttp://www.blogger.com/profile/01936794393501829574noreply@blogger.com29tag:blogger.com,1999:blog-10398716.post-1118390161554317252005-06-10T09:29:00.000+02:002005-06-10T09:56:01.560+02:00

Last week I was involved in solving a performance problem for a customer that suffered from enormous performance slow downs. The funny thing was that there was a special task force assigned to this problem by the customer and they had been working since half december on this problem. That task force consisted of 22 people and some were actually flown in to help solve the problem. A consultant

OraPerfhttp://www.blogger.com/profile/01936794393501829574noreply@blogger.com114tag:blogger.com,1999:blog-10398716.post-1118360567790826012005-06-10T00:15:00.000+02:002005-06-10T01:42:47.796+02:00

In 1995 I started to work on the wait events paper based on Oracle7.3, and that formed the basis for the YAPP white paper. That in turn formed the basis for the wave of response time tuning books and presentations. Now it is funny to see how the same thing is rehashed over and over again and nothing really new is being added. In fact I believe that all the attention on wait events and response

OraPerfhttp://www.blogger.com/profile/01936794393501829574noreply@blogger.com38