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Fedora 22/23 and Oracle 11gR2/12cR1

linux-tuxAs always, installations of Oracle server products on Fedora are not a great idea, as explained here.

I was reading some stuff about the Fedora 23 Alpha and realised Fedora 22 had passed me by. Not sure how I missed that. :)

Anyway, I did a run through of the usual play stuff.

Web Pages Not Databases – Part 2: Fail2ban, Apache, IP Addresses, Linux, SELinux

August 23, 2015 (Back to the Previous Article in this Series) I started using Linux in 1999, specifically Red Hat Linux 6.0, and I recall upgrading to Red Hat Linux 6.1 after downloading the files over a 56k modem – the good old days.  I was a little more wise when I upgraded to another […]

Installing the Oracle database in docker

This blogpost is about how to install and run the Oracle database in docker. Please mind this is not an officially supported virtualisation platform for the Oracle database. This is a proof of concept setup.

Linux host setup.
In my setup, I used a linux host, freshly installed with Oracle Linux 6.7, which is going to be used as docker server. Please mind you need to leave diskspace (or a disk device) unused for the commonly documented docker setup with the btrfs driver. The root filesystem is using a ext4 filesystem by default. For the proof of concept setup, a 20G diskspace for the Operating system only is enough. I used the minimal linux installation.

The first step is to add a disk, or use a partition and format it with btrfs and mount it:

Preparing a Oracle Linux for a Vagrant box

This post is an overview of an installation and configuration process of the Oracle Linux, which will be used as a machine “box” for Vagrant software using a Virtual Box platform.

Post itself is divided into two parts:

  1. Oracle Linux installation (points 1 to 12)
  2. Vagrant box configuration (points 13 to 16)


Part 1 – Oracle Linux installation

 

1. Create a new Virtual Machine - machine name will be used later to create Vagrant box

Preparing a Oracle Linux for a Vagrant box

This post is an overview of an installation and configuration process of the Oracle Linux, which will be used as a machine “box” for Vagrant software using a Virtual Box platform.

Post itself is divided into two parts:

  1. Oracle Linux installation (points 1 to 12)
  2. Vagrant box configuration (points 13 to 16)


Part 1 – Oracle Linux installation

 

1. Create a new Virtual Machine - machine name will be used later to create Vagrant box

CloneDB in Oracle 12.1.0.2

I personally really like CloneDB, a way to thin-clone an Oracle database over NFS. This can be quite interesting, and I wanted to update my blog for 12.1.0.2.3 (April PSU). Tim Hall has a good example for 11.2.0.2 and later with further references.

My setup is as follows:

Little things worth knowing: Data Guard Broker Setup changes in 12c

One of the problems I have seen when deploying Data Guard for systems such as RAC One Node and policy managed databases was the static listener configuration you needed in 11.2. This has changed with 12c for the better if you are using Grid Infrastructure.

http://docs.oracle.com/database/121/DGBKR/install.htm

In the section about static listener registration a little addendum can be found (thanks to Patrick Hurley/@phurley for pointing this out to me!):

“A static service needs to be defined and registered only if Oracle Clusterware or Oracle Restart is not being used.”

This is good news, let’s put it to the test; I’m a great fan of Oracle Restart. If I ever find the time I’d like to repeat this test with clustered Grid Infrastructure. I think the quote mentioned earlier still stands true but I would like to see it with my own eyes.

MobaXterm 8.0

command-promptI just noticed MobaXterm 8.0 was released a few days go.

Downloads and changelog available in the usual places.

Happy unzipping!

Cheers

Tim…


MobaXterm 8.0 was first posted on July 24, 2015 at 3:19 pm.
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Oracle 12 and latches

Oracle DBAs who are so old that they remember the days before Oracle 11.2 probably remember the tuning efforts for latches. I can still recall the latch number for cache buffers chains from the top of my head: number 98. In the older days this was another number, 157.

But it seems latches have become less of a problem in the modern days of Oracle 11.2 and higher. Still, when I generate heavy concurrency I can see some latch waits. (I am talking about you and SLOB mister Closson).

I decided to look into latches on Oracle 12.1.0.2 instance on Oracle Linux 7. This might also be a good time to go through how you think they work for yourself, it might be different than you think or have been taught.

How long does a logical IO take?

This is a question that I played with for a long time. There have been statements on logical IO performance (“Logical IO is x times faster than Physical IO”), but nobody could answer the question what the actual logical IO time is. Of course you can see part of it in the system and session statistics (v$sysstat/v$sesstat), statistic name “session logical reads”. However, if you divide the number of logical reads by the total time a query took, the logical IO time is too high, because then it assumed all the time the query took was spend on doing logical IO, which obviously is not the case, because there is time spend on parsing, maybe physical IO, etc. Also, when doing that, you calculate an average. Averages are known to hide actual behaviour.