Top 60 Oracle Blogs

Recent comments

October 2013

Databases for every developer like source code?

Three part post


The simple truth is that databases can’t be given to every developer like source code.

Abstracts, Reviews and Conferences, Oh My!

So yes, I’ve been involved in a number of conferences and in a number of different roles.  I started out presenting, then volunteering  at conferences,  reviewing abstracts, then as a track lead and now as a conference director for RMOUG.  This year I also am the database track lead for ODTUG’s KSCOPE for a second year in a row.

EM administrator jobs

Interesting that we’re starting to see this sort of thing (names removed): Job Title: Senior Oracle Enterprise Cloud Administrator General Information Job Type: Information Technology Base Pay: N/A Req’d Education: 4 Year Degree Employee Type: Full-Time Req’d Experience: 5 to greater than 15 years Req’d Travel: Not Specified Manages Others: False Relocation Covered: False POSITION […]

Parallel Execution – 2

Since I’m going to write a couple of articles dissecting parallel execution plans, I thought I’d put up a reference post describing the set of tables I used to generate the plan, and the query (with serial execution plan) that I’ll be looking at. The setup is a simple star schema arrangement – which I’ve generated by created by creating three identical tables and then doing a Cartesian join across the three of them.

WebLogic 11g, Forms, ADF, Oracle Linux and VMware

Following on from my recent batch of “what I’m doing at the moment” style posts, I just thought I would mention some of the infrastructure I’ve been installing and configuring recently…

We are still part way through a migration from Oracle Application Server to WebLogic 11g. There are many applications to migrate and test, fortunately not by me, but they fit into two main categories.

Transcript of the interview with Jonathan Lewis

If you missed the interview with Jonathan Lewis or don’t want to spend 93 minutes watching it, here is its transcript. Thanks to Stanislav Osekin from Innova, who did most of the hard work. I have only corrected special Oracle terms. Also thanks to Jonathan, who helped me in several complex cases where I couldn’t understand the wording.

T: Hello and welcome! My name is Timur Akhmadeev and I’m sitting here at the Innova office with Jonathan Lewis. Hello, Jonathan!

J: Morning, Timur! Nice to be here!

T: Nice to see you too! Thank you for coming!

J: My pleasure!

The Exadata wait event ‘cell smart table scan’

The purpose of this post is to show what the wait event ‘cell smart table scan’ means, based on reproducible investigation methods.

First of all, if you see the ‘cell smart table scan’ event: congratulations! This means you are using your exadata how it’s intended to be used, which means your full table scan is offloaded to the cells (storage layer), and potentially all kinds of optimisations are happening, like column filtering, predicate filtering, storage indexing, etc.

But what is exactly happening when you see the wait event ‘cell smart table scan’? Can we say anything based on this waits, like you can with other wait events?

Control Charts

Last week, while working on customer engagement, I learned a new method of quantifying behavior of time-series data. The method is called “Control Chart” and credit to Josh Wills, our director of data science, for pointing it out. I thought I’ll share it with my readers as its easy to understand, easy to implement, flexible and very useful in many situations.

The problem is ages old – you collect measurements over time and want to know when your measurements indicate abnormal behavior. “Abnormal” is not well defined, and thats on purpose – we want our method to be flexible enough to match what you define as an issue.

For example, lets say Facebook are interested in tracking usage trend for each user, catching those with decreasing use

There are few steps to the Control Chart method:

Parallel Execution – 1

When you read an execution plan you’re probably trying to identify the steps that Oracle went through to acquire the final result set so that you can decide whether or not there is a more efficient way of getting the same result.