With Exadata version 220.127.116.11.0 came the Unbreakable Linux Kernel for Exadata, which had been the stock EL5 redhat kernel prior to this version (2.6.18). With the unbreakable kernel came the opportunity to run the perf utility. This utility has the opportunity to see which functions are active inside an executable when there’s a symbol table. And the oracle database executable has a symbol table! One reason to do this, is to get a more granular overview of what the Oracle database is doing than the wait interface, especially to get a more detailed overview of what the database is doing in what is visible in the wait interface as ‘on cpu’.
I mentioned in a previous post that my company were planning to move all of our middle tier infrastructure and some of our Oracle databases to Oracle Linux running on a virtual infrastructure. That process is now underway.
Persuading the company to ditch Red Hat Enterprise Linux (RHEL) in favor of Oracle Linux took a bit of effort, partly due to some Fear, Uncertainty and Doubt (FUD) spread by one of the vendors we use. In the process of trying to counter the FUD I put together an Oracle Linux FAQ document. I thought it might come in handy for anyone else in a similar position, so I thought I would make it available on my site.
In order to look how Exadata smartscans are different, first let’s have a peek the Oracle full segment/multiblock read evolution as short as possible:
a) Traditional multiblock reads, visible via the event ‘db file scattered read’
The essence is: Multiple adjacent blocks are read from disk, and put in the buffercache. Because every read is sequentially processed, IO latency is a performance penalty for every physical read. This works roughly this way: get a set of adjacent blocks from the segment header, fetch these blocks from disk, process these blocks, then get the next set of adjacent blocks, fetch these blocks from disk, process these blocks, etc.
Last year I wrote an article about the installation of Oracle Forms and Reports Services 11gR2 on Oracle Linux 5. I’ve now written the article for Oracle Forms and Reports Services 11gR2 on Oracle Linux 6. The latest patch of F&RS is certified for OL6, along with JDK6 and JDK7.
In addition to the installation articles, I’ve compiled a collection of random notes about post-installation configuration into a separate article. I keep adding to it every time I come across a new (for me) issue.
Hot on the heels of the recent UltraEdit v19 release for Windows, comes the UltraEdit v4 Beta II release for Linux/Mac.
I’ve just started using it and so far so good. They usually progress through the betas pretty quick. I didn’t have time to install the beta I before this one dropped.
I spent yesterday neatening up a few old articles. For the most part it is a bit of a dull process, but it has to be done every so often.
Followers of the blog will know I dig virtualization. I first ran Oracle in virtualized environments over a decade ago.
In my current company there is a strong virtualization presence in the Windows space. Pretty much all Windows servers, including those running MS SQL Server, are actually VMs running on a VMware farm. The UNIX/Linux side is a little different. Most stuff is still done on physical boxes and what little virtualization is done, uses CentOS and KVM for freebie open source solutions.
There are a lot of architectural changes going on at the moment and I’ve been pushing *very hard* for a switch to the virtual infrastructure (VI) for all our middle tier servers and a few of our databases. It is looking very likely (but not guaranteed) that this will happen.
To use ASMlib or not to use ASMlib? That is the question. Or at least, that is a question that frequently crops up when I'm on consulting engagements with customers. I have personally changed my mind a couple of times on this exact question, and I'm currently sat with one leg on either side of [...]
I mentioned in my previous post on this subject that I had 5 more objectives yet to cover. The articles for those objectives have now been added to the website.