I heard a strange report from a client late last week - they weren't getting any smart scans on their Exadata - a data warehouse, no less (and we checked to see if cell_offload_processing was set to true). Queries would run normally, but for some reason, the "cell physical IO (more...)
I have seen several clients who are struggling to decode page allocation failures on Exadata, in this post i will try to explain how to read the backtrace. The following is an anonymized client case where page allocation failures are leading up to a node reboot.
Jan 1 11:58:02 dm01db01 (more...)
Klar, dass bei der Deutschlandcard AG enorme, ständig wachsende Datenmengen anfallen. Um dauerhaft hohe Performanz und Verfügbarkeit garantieren zu (more...)
I’ll start with three observations:
- Computer systems can’t be entirely tightly coupled — nothing would ever get developed or tested.
- Computer systems can’t be entirely loosely coupled — nothing would ever get optimized, in performance and functionality alike.
- In an ongoing trend, there is and will be dramatic refactoring as (more...)
Just a quick reminder - I'll be presenting my "Getting Ready for Exadata" seminar in London on July 1. We'll cover various topics on what you need to know before you purchase an Exadata and how to manage one of these systems on a daily basis. We'll have lots of (more...)
Rene Kundersma at Oracle just published a nifty new utility named dbnodeupdate.sh that will assist with the sometimes-cumbersome process of updating the compute nodes in an Exadata environment. Starting last year with 188.8.131.52.0, Oracle introduced yum updates for the Exadata compute nodes. Previously, each Exadata (more...)
- The trend to clustered computing is sustainable.
- The trend to appliances is also sustainable.
- The “single” enterprise cluster is almost as much of a pipe dream as the single enterprise database.
I shall explain.
Arguments for hosting applications on some kind of cluster include:
- If the workload requires (more...)
Smart Scans are part of what Kerry Osborne calls the ‘secret sauce’ of Exadata, and he’s right. Smart Scans can definitely improve throughput by using the various optimizations to reduce the amount of data read and the volume of data returned to the database servers. You really want to have them working on an Exadata machine. But how do you know they’re working? Let’s look at a couple ways to prove you have Smart Scans working for you.
The easiest way to prove you have a Smart Scan working (from the database server side) is to query the V$SQL view (more...)
This FF is a bit of a follow-up to the one I posted last week on PL/SQL skills and a comment made by Noons on how much knowledge you need to be an OakTable member.
I have a question to answer and I would appreciate other people’s opinion. Should there be more intro talks at conferences? If so, should the experts be giving them?
I am an OakTable member (and really quite worryingly proud about that) and I guess that means I know a lot about some aspects of Oracle. But also, and this is a key part of being (more...)
When the 184.108.40.206.1 release of the Exadata Storage Server software was released, I was a little excited. There were numerous oneoff patches for the previous release, 220.127.116.11.0, which was the first version to support the Exadata X3, writeback flashcache, run UEK on the X#-2 systems, etc. With that many large changes introduced in one version, it was likely to see some bugs in the .0 release. Fortunately, Oracle was quick to fix many of those issues, but it resulted in several separate patches to update the cellsrv software.
I was working with (more...)
1. It boggles my mind that some database technology companies still don’t view compression as a major issue. Compression directly affects storage and bandwidth usage alike — for all kinds of storage (potentially including RAM) and for all kinds of bandwidth (network, I/O, and potentially on-server).
Trading off less-than-maximal compression (more...)
Well, I’ve just finished pushing the last few bits into my suitcase for my trip to the US for the Rocky Mountain User Group Training Days 2013.
It is a few years since I went to the US for pleasure (3 years?) and much longer since I went there on a combined work/pleasure trip – as I HATE going through US immigration.
I was tempted into this trip when I met up with a fellow OakTable member Tim Gorman at the Slovenia User Group last October. Tim was a true gentleman throughout that conference (and this is not to (more...)