Sometimes development is just work

Sometimes development is just work

No matter how cool your job is, no matter how many people are looking at you or your company for best practises, sometimes developing software is just work ;-) On this blog I’ve shared examples of companies that people nowadays see as successful, like Netflix, Twitter, Spotify, or the online retailer

To prove my point I’ve checked the release notes of Netflix and Spotify apps. Here (more...)

Book – The Phoenix Project

Book – The Phoenix Project

Book The Phoenix ProjectThe Phoenix Project: A Novel About IT, DevOps, and Helping Your Business Win is written the by Gene Kim in the tradition of The Goal (1984, by Dr. Eliyahu M. Goldratt). The Goal is a management novel explaining the Theory of Constraints. This book, The Phoenix Project shows how the theory in The Goal works in an IT environment.

The Goal – Theory of Constraints

In simple terms the Theory (more...)


In der Vergangenheit habe ich schon häufiger erwähnt, dass ich den SQL Developer für ein sehr brauchbares Werkzeug halte, das mit erstaunlichem Tempo weiterentwickelt wird - insbesondere, wenn man bedenkt, dass es ganz und gar kostenlos ist. Fast noch interessanter finde ich aber das vor wenigen Tagen vorgestellte zugehörige Tool SDSQL, das die sqlplus engine des SQL Developers als command line interface verfügbar macht - und zahlreiche Features hinzufügt, die im klassischen sqlplus fehlen. Die (more...)

Creating Intuitive & Interactive Dashboards with the ADF Data Visualization Components

Last week I presented at the UKOUG’14 conference on creating intuitive & interactive dashboards with the ADF Data Visualization Components. Frequently end-users are overwhelmed with too much and confusing information displayed in rows and columns. It can be difficult to quickly get the relative significance. This session discussed how to create intuitive, interactive dashboards made with the ADF Data Visualization Components. You can use of the power of visualization to present information; to call the end-user to action (more...)

The caveats of running .sql scripts with GUI tools

One of my pet peeves is people using GUI tools like Toad or SQL Developer while running release scripts on test, acceptation or production systems. Actually, pet peeves is putting it too mildly. Ive had to troubleshoot enough incidents because of this to hold a serious grudge against that careless practice. Especially when running a script that manipulates data, you are much better of using SQL*Plus. Most hardboiled DBAs probably know what Im talking about, (more...)

Life of an Oracle I/O: tracing logical and physical I/O with systemtap

Topic: This post is about tracing logical and physical reads in Oracle using systemtap. You will find a few examples illustrating the main mechanisms used by Oracle to do physical and logical I/O and you will learn how to build systemtap scripts to further explore and troubleshoot Oracle I/O.

Introduction: Performing input/output to and from the storage media, i.e. physical I/O, is one of the critical tasks underlying all database engines. When accessing data (more...)

Spotify engineering culture part I & II

Spotify engineering culture part I & II

I’ve been reading quite some article on engineering culture and ways of working. The videos on Spotify Labs are among the best sources I’ve watched or read in the last year on the subjects of agile and culture. Recently the second part of their series on Spotify’s engineering culture was released.

Spotify engineering culture part I

Important take aways for me were:

  • Agile over scrum
  • Principles over practices
  • (more...)

SQL Developer Neue Version & Hidden Features

Es gibt eine neue Version vom Oracle SQL Developer 4.0.3:

Hier noch ein paar Links zu den Hidden Features im SQL Developer
Top 10 Voreinstellungen:

Automatisches öffnen einer Tabelle verhindern:

Formatiere SQL Code in lower/UPPER:

Verbindung zu anderen Datenbanken herstellen:

Wenn Ihr noch nicht allzu viel Erfahrung mit dem SQL Developer habt, dann solltet Ihr euch diese Seiten mal anschauen:

SystemTap into Oracle for Fun and Profit

Topic: This post is about using SystemTap for investigating and troubleshooting Oracle RDBMS. In particular you will learn how to probe Oracle processes and their userspace functions. These techniques aim to be useful as well as fun to learn for those keen into peeking under the hood of the technology and improve their effectiveness in troubleshooting and performance investigations.


Userspace probing is a very powerful technique that can be used to complement the available (more...)

How to identify SQL performing poorly on an APEX application?

Oracle Application Express (APEX) is a great tool to rapidly develop applications on top of an Oracle database. While developing an internal application we noticed that some pages were slow, meaning taking a few seconds to refresh. Suspecting there was some poorly performing SQL behind those pages, we tried to generate a SQL Trace so we could review the generated SQL. Well, there is no out-of-the-box instrumentation to turn SQL Trace ON from an (more...)

Book – Hatching Twitter: A True Story of

Book – Hatching Twitter: A True Story of

Book - Hatching Twitter: A true story of...Just finished reading Hatching Twitter: A True Story of Money, Power, Friendship, and Betrayal and I must say that I wasn’t as impressed as when reading for example The Everything Store. The book is more about politics and opportunities than about creating opportunities and value or generating great ideas that others can build on. Of course this can still offer a great story and be a good (more...)

Book – The everything store

Book – The everything store

The everything store

The everything storeThe idea of the everything store was simple: an Internet company that served as the intermediary between customers and manufacturers and sold nearly every type of product, all over the world. It is the story of, one of the most successful companies in the world. And the story of its driven founder Jeff Bezos.

Reading the book I think that there are a few (more...)

Reading list of 2014 so far

Reading list of 2014 so far

In this blog post I’ll share a list of books I read during the first months of 2014. There is more business focus compared to previous years…

The everything store

The everything storeThe everything store is one of the books I liked reading most of my reading list this year. It tells the story of so far; The vision and ways of working of the company and it’s founder (more...)

Flame Graphs for Oracle

Topic: This post is a hands-on introduction to using on-CPU Flame Graphs for investigating Oracle workloads. This technique is about collecting and analyzing sampled stack trace data to analyze and troubleshoot Oracle processes at the OS level (in particular applied to Linux).

Motivations: The techniques and tools described here can be used for performance investigations to complement wait-event based information gathered from the Oracle engine, such as information available with ASH and sql monitoring. They (more...)


My carpenter has been putting in a new floor in a room in my house, and I noticed that he makes some of his tools as he goes along.

It’s not that he doesn’t have a hammer and a cordless electric screwdriver. But every once in a while, he needs to move, align or support something in a way that his standard tools do not support. So he immediately builds an ad-hoc tool out of (more...)

Recent Updates of OraLatencyMap and PyLatencyMap

Topic: This post introduces the latest changes to OraLatencyMap and PyLatencyMap, two custom tools for collecting and displaying Oracle wait event latency details using heatmaps.

OraLatencyMap is a SQL*Plus tool, with a core written in PL/SQL, aimed at studying Oracle random I/O by displaying the latency drill-down of the wait event 'db file sequential read' using heatmaps. The tool can also be used to collect and display event latency histograms for any other Oracle wait (more...)

Wait Event History Sampling, an Experiment in Oracle Performance Analysis

Topic: This post is about a performance analysis technique based on high frequency sampling of wait event history data in Oracle. Two scripts are provided for performing this type of analysis and two example cases are discussed applied to the study random read latency and read workload characterization.

Context: In the context of performance analysis, for example for a study of I/O response time, I want to analyze the flow of all wait events for (more...)

Daylight Saving Time Change and AWR Data Mining

Topic: this article is about a tip for Oracle 11.2 and higher on how to handle DST change when querying directly the AWR repository. In addition a few comments on Perfsheet4, a tool to extract and plot AWR data in Excel.

Introduction: Statspack and more recently AWR reports, (more...)

Decrypt Oracle and database link passwords

At Derbycon 3.0, László Tóth and Ferenc Spala  gave a a new presentation “What’s common in Oracle and Samsung? They tried to think differently… ” (Video). The main focus of the presentation was the Samsung encryption and a new framework called sandy but there was also a small (more...)

Getting Started with PyLatencyMap: Latency Heat Maps for Oracle and DTrace

Topic: this is a getting-started article for PyLatencyMap, a performance tool for real-time investigation and troubleshooting of latency data. Contains examples relevant for the Oracle RDBMS and for DTrace.

Getting started

Download the latest version of PyLatencyMap (also available on GitHub). At the time of this writing PyLatencyMap (more...)