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Redo OP Codes:

This posting was prompted by a tweet from Kamil Stawiarski in response to a question about how he’d discovered the meaning of Redo Op Codes 5.1 and 11.6 – and credited me and Julian Dyke with “the hardest part”.

Over the years I’ve accumulated (from Julian Dyke, or odd MoS notes, etc.) and let dribble out the occasional interpretation of a few op codes – typically in response to a question on the OTN database forum or the Oracle-L listserver, and sometimes as a throwaway comment in a blog post, but I’ve never published the full set of codes that I’ve acquired (or guessed) to date.

Fast Now, Fast Later

The following is the text of an article I published in the UKOUG magazine several years ago (2010), but I came across it recently while writing up some notes for a presentation and thought it would be worth repeating here.

Fast Now, Fast Later

The title of this piece came from a presentation by Cary Millsap and captures an important point about trouble-shooting as a very memorable aphorism. Your solution to a problem may look good for you right now but is it a solution that will still be appropriate when the database has grown in volume and has more users.

I was actually prompted to write this article by a question on the OTN database forum that demonstrated the need for the basic combination of problem solving and forward planning. Someone had a problem with a fairly sudden change in performance of his system from November to December, and he had some samples from trace files and Statspack of a particular query that demonstrated the problem.

The $50 Million Hyphen

There are a plethora of mishaps in the early space program to prove the need for DevOps, but Fifty-five years ago this month, there was one in particular that is often used as an example for all.  This simple human error almost ended the whole American space program and it serves as a strong example of why DevOps is essential as agile speeds up the development cycle.  

Upgrading an Amazon EC2 Delphix Source, Part I

For a POC that I’m working on with the DBVisit guys, I needed a quick, 12c environment to work on and have at our disposal as required.  I knew I could build out an 11g one in about 10 minutes with our trust free trial, but would then need to upgrade it to 12c.

Disable snapshots to Delphix Engine

This is a simple prerequisite before you upgrade an Oracle source database and takes down the pressure on the system, as well as confusion as the database upgrades the Oracle home, etc.

Simply log into the Delphix Admin console, click on your source group that the source database belongs to and under Configuration, in the right hand side, you’ll see a slider that needs to be moved to the “disable” position to no longer take interval snapshots.

Little Things Doth Crabby Make – Part XXI. No, colrm(1) Doesn’t Work.

This is just another quick and dirty installment in the Little Things Doth Crabby Make series. Consider the man page for the colrm(1) command:

Little Things Doth Crabby Make – Part XX – Man Pages Matter! Um, Still.

It’s been a while since I’ve posted a Little Things Doth Crabby Make entry so here it is, post number 20 in the series. This is short and sweet.

I was eyeing output from the iostat(1) command with the -xm options on a Fedora 17 host and noticed the column headings were weird. I was performing a SLOB data loading test and monitoring the progress. Here is what I saw:


The title is a well-known shorthand for parameter optimizer_features_enable and it has been the topic of a recent blog post by Mike Dietrich in which he decries the practice of switching the parameter back to an older version on an upgrade (even though, as he points out, Oracle support has been known to recommend it and the manuals describe – though not with 100% accuracy – why you might do so).

I am one of the people who will suggest that on the upgrade a client should consider setting the optimizer_features_enable to the version just left behind as a strategy for getting to a newer version of the base code while minimising the threat of plan instability, so I’m going to play devil’s advocate in this case even though, as we shall see, I am nearly 100% in favour of Mike’s complaint.

DevOps is Ruining the DBA?

Database Administrators, (DBAs) through their own self-promotion, will tell you they’re the smartest people in the room and being such, will avoid buzzwords that create cataclysmic shifts in technology as DevOps has.  One of our main role is to maintain consistent availability, which is always threatened by change and DevOps opposes this with a focus on methodologies like agile, continuous delivery and lean development.

ODA X6 installation: re-image

The Oracle Database Appliance is shipped with a bare-metal installation which may not be the latest version. You may want to have it virtualized, or get the latest version to avoid further upgrade, or install an earlier version to be in the same configuration as another ODA already in production. The easiest for all cases is to start with a re-image as soon as the ODA is plugged. This post is not a documentation, just a quick cheat sheet.

I don’t want to spend hours in the data center, so the first step, once the ODA is racked, cabled and plugged, is to get it accessible from the management network. Then all tasks can be done from a laptop, accessing the ILOM interface through a browser (Java required, and preferably 32-bits) before the public network is setup.

Development and the Importance of Containerizing

I’ve been at KSCOPE 2017 all week and it’s been a busy scheduled even with only two sessions.  Its just one of those conferences that has so much going on all the time that the days just speed by at 140MPH.