This category contains 25 posts

PostgreSQL Invalid Page and Checksum Verification Failed

At the Seattle PostgreSQL User Group meetup this past Tuesday, we got onto the topic of invalid pages in PostgreSQL. It was a fun discussion and it made me realize that it’d be worth writing down a bunch of the stuff we talked about – it might be interesting to a few more people too! … Continue reading

Understanding CPU on AIX Power SMT Systems

This month I worked with a chicagoland company to improve performance for eBusiness Suite on AIX. I’ve worked with databases running on AIX a number of times over the years now. Nevertheless, I got thrown for a loop this week. TLDR: In the end, it came down to a fundamental change in resource accounting that … Continue reading

Lessons from Africa, Part 2

Last week was busy… making travel arrangements for this week’s trip to New York (technically Jersey) and some light analysis of AWR reports from exadata RAT runs and some heavy troubleshooting of a Solaris x86 RAC cluster with random node reboots. (I think I finally traced the node reboots to a kernel CPU/scheduling problem). I … Continue reading

Lessons From Rural Africa

It has been nine months since I’ve written here. Needless to say, a lot has happened! First, my family was living in Africa for three months earlier this year while I did some tech work at an NGO hospital. Second, upon our return I decided to join the good people at Pythian. I’m not moving … Continue reading

RAC Attack – Oracle Cluster Database at Home

First of all, the RAC Attack deep dive at Collaborate went great – thanks to everyone who participated! The room was full (20 participants) and I got evaluations from about half of them. Here’s a summary of the eval results: 100% class met expectations, would recommend to others 66% easy to follow, could use skills … Continue reading

Mysterious Oracle Net Errors

Yesterday, I had a fight to the death with a nasty Oracle Net problem. The battle consumed a little more of the day than I intended… but it was worthwhile for the sweet taste of victory. Everything started with this short, innocent-seeming instant message: there is something wrong with a 10g server config. connecting to … Continue reading

RAC Investigation on Low-Memory Linux

Back in the Oracle 9i days, I was one of those people who got on eBay to buy firewire PCI cards and disks that could do non-exclusive login.  Remember that?  The first time a little test cluster could be cheap enough for the home enthusiast?  I still have the parts in my closet. Of course, … Continue reading

Future of OCFS2

At the company where I’m working right now, I’m part of an architecture effort to come up with our standard design for RAC on Linux across the firm. There will be dozens or possibly hundreds of deployments globally using the design we settle on. We’re internally debating whether or not we should include OCFS2 in … Continue reading

Robust Software Version Numbering

This article isn’t directly database-related, but I think it’s a great software engineering topic so it seemed worth writing about. Right now I’m involved in a project that involves releasing software packages of a few different flavors. Some of them are other people’s software that we’re re-packaging (like oracle database binaries) and some are code … Continue reading

Parsing LISTENER.ORA with awk and sed

Happy Thanksgiving to everyone in the US! And happy belated thanksgiving to everyone in Canada since you celebrated back at the beginning of October. :) I’ve been doing a lot of scripting work lately. Although I can’t write about everything I’m doing, I would like to post a pattern that I thought could be useful … Continue reading


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contact: 312-725-9249 or schneider @ ardentperf.com




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