LAC de architect tussen 44 scrum teams in de 90e sprint

LAC de architect tussen 44 scrum teams in de 90e sprint

Dit is de presentatie die ik op 25 november 2015 gaf op het Landelijk Architectuurcongres over Agile Architectuur. De titel: de architect tussen 44 scrum teams in de 90e sprint:


Why ALL Tools in at Your Disposal ARE IMPORTANT

After my AWR Warehouse session at DOAG in Nuremberg, Germany last week, an attendee asked me if he really needed to use trace files anymore with the value provided by AWR, (Automatic Workload Repository) and ASH, (Active Session History.)  I responded that trace files were incredibly valuable and should never be discounted.

To use an analogy, when I was 22 years old, and entered a doctor’s office missing a small percentage of my visual (more...)

Oracle Wait Events Investigated with Extended Stack Profiling and Flame Graphs

Topic: this post is about investigating Oracle wait events using stack profiles and flame graphs extended with OS-process state and Oracle wait event details.

Context: The case of the DB Time > CPU Time + Wait Time

Oracle instrumentation provides wait event and CPU time accounting, a powerful and readily accessible data source for performance troubleshooting. An Oracle session at a given point in time is either on CPU, for example when processing data from cache, (more...)

Wait Event Analyse mit Flame Graphs

Luca Canali hat im Databases at CERN Blog wieder einmal eine detaillierte Analyse vorgestellt, in der er Flame Graphs mit Extended Stack Profiling verbindet und damit die Aussagen des Oracle Wait Interfaces näher beleuchtet. Der eigentliche Anlass der Untersuchung ist dabei die Beobachtung des Auftretens von Fällen, in denen die DB time größer ist als die Summe von CPU time und Wait time, was a) nicht vorkommen sollte und b) mit dem Einsatz moderner Storage (more...)

Oracle JET Charts – Do we need alternatives anymore?

After I looked through the chart types supported by the new Oracle JET framework I asked myself if we need other chart plugins like D3JS or RaphaelJS in future APEX releases anymore?

The answer is: Yes in special cases.

My supposition is that we can use all available JET charts in one of the next versions of Oracle APEX.

Now I will describe the "special case" with two examples where other chart frameworks still make sense:
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ScaleScale on the stack behind Netflix scaling

ScaleScale on the stack behind Netflix scaling

Over at ScaleScale, a blog about all the good stuff when it comes to scaling, an interesting post was published on the stack behind Netflix scaling. Since Netflix is quite public about how they operate, the post put was together with stuff from around the internet.

Stack Behind Netflix Scaling Like Spotify Netflix is kind of famous for creating and scaling their culture. This gives some important context to the culture (more...)

A business that can endure the future

A business that can endure the future

Even if your business can sort of escape competition by crafting a monopoly, it is only a great business if it can endure the future. Is one of the statements in the book Zero to One by Peter Thiel and Blake Masters.
A great business is defined by it’s ability to create cash flow in the future. In other words, the value of a business today is the (more...)

Was ist Oracle JET

Oracle JET ist das neueste Oracle Development Werkzeug mit dem Ziel moderne Webapplikationen auf Basis von Javascript zu bauen.

Die Grundlage dafür bildet ein eigens dafür entwickeltes JavaScript Development Framework das zusätzlich um mehrere mehr oder weniger bekannte OpenSource JS Frameworks (jQuery, RequireJS, Knockout und weitere) erweitert wurde.

Witzigerweise scheint Oracle JET nicht allein zu sein, denn die Abkürzung bezeichnet innerhalb des Oracle Toolsets zwei unterschiedliche Technologien.
Das neue Oracle JET (JavaScript Extension Toolkit) und (more...)

Velocity 2015 Amsterdam

Velocity 2015 Amsterdam

Thursday was a very interesting day for me at Velocity 2015 Amsterdam, build resilient systems at scale. It is one of the best conferences I attended in the last years. Using some quote’s and bullets I’ll give a little insight.

On retro’s, post mortems, etc

Lindsay Holmwood showed that what goes wrong in retrospectives, post mortems and the like is mostly based on:

Oracle Tools: pathfinder, SQLd360, eDB360

Ein paar Links von Mauro Pagano und Carlos Sierra:
Zu den ersten beiden Links ist nicht viel zu sagen, das sind kurze Einführungs-Videos zu den jeweiligen Tools. Der dritte Artikel stellt das Pathfinder Tool vor, das eine recht brachiale Form der Suche nach besseren Ausführungsplänen verwendet: es führt eine (more...)

Linux Kernel Stack Profiling and Flame Graphs Applied to Oracle Investigations

Topic: This blog post is about kernel stack profiling and visualization with flame graphs with examples.

Stack profiling and flame graphs are very useful techniques and tools for troubleshooting and investigating workloads at the OS-level and understand which code path take most of the execution time. You can find extensive material and examples o flame graphs in Brendan Gregg's website and blog. A few additional examples of using stack tracing and flame graphs for (more...)

Continuous Delivery at

Continuous Delivery at

Last month two of our software engineer Mihaela Tunaru and Mary Gouseti were invited to give a presentation of how continuous delivery is done at The presentation gives a good insight in the state of continuous delivery at from a software engineering perspective.

In case you want to know more from the operations perspective check Mayfly on GitHub and the presentation below. Maarten Dirkse gave a (more...)

Bloomberg Innovation Index

Bloomberg Innovation Index

bloomberg innovation index logoBesides the Global Innovation Index there are other indexes measuring and comparing innovation around the globe. Another interesting index is the Bloomberg Innovation Index.

Bloomberg’s innovation index is based on six equally weighted metrics. Their scores are combined to provide an overall score for each country from zero to 100.

  • Research and development – Research and development expenditure as a percentage of GDP.
  • Manufacturing – since it takes a lot of knowledge (more...)

Spalten als Zeilen ausgeben mit SQLcl

Ein Feature, das ich in psql für postgres sehr schätze, ist die Möglichkeit, durch das Kommando x die "erweiterte Anzeige" zu aktivieren, die Datensätze in einer Record-Darstellung präsentiert, also:

select * from t;

a | b | c
1 | 2 | 3
4 | 5 | 6

--> Switch display with x

select * from t;

-[ RECORD 1 ]
a | 1
b | 2
c | 3
-[ RECORD 2 ]

Global Innovation Index 2015

Global Innovation Index 2015

The Global Innovation Index (GII) 2015 is an annual publication which features a composite indicator that ranks countries/economies in terms of their enabling environment to innovation and their innovation outputs. The GII covers 141 economies around the world and uses 79 indicators across a range of themes. The Global Innovation Index 2015 was created by Cornell University, INSEAD, and the World Intellectual Property Organization (WIPO).

Here is an overview (more...)

Fehlende Foreign Keys mit dem SQL Developer ermitteln

Regelmäßig erinnert mich Jeff Smith mit seinen Artikeln daran, dass es doch eine gute Idee wäre, endlich mal dazu überzugehen, den SQL Developer zu meinem Standardwerkzeug zu machen. In einem aktuellen Beitrag weist er beispielsweise darauf hin, dass der SQL Developer Data Modeller anhand von Spaltennamen und Datentypen dazu in der Lage ist, über eine Option "Discover Foreign Keys" Vorschläge zur Erzeugung fehlender FK-Constraints zu generieren. Das erfordert natürlich eine konsistente Namensgebung, so dass das (more...)

A Short Note on Pesky CSSCAN Results Before a Characterset Change

A client of mine was busy correcting one of his development streets and therefore the NLS charactersets of about 10 EE databases had to be changed.
Most of the databases were originally configured with WE8ISO8859P15, others with WE8ISO8859P1 and all of them had to get WE8MSWIN1252. Some of them were single instances (export, development and test), some RAC (acceptance) and some of them were RAC plus Dataguard (production, for the procedure (more...)

Forcing a “Nested Loop only” Execution Plan

Sometimes you do what you have to do. So here I confess doing something I usually avoid: forcing an Execution Plan (which is not the same as using a more conventional method for Plan stability).

This is a case on base release where the application vendor sets the optimizer to 9i, and tweaks other CBO parameters in questionable ways, then some queries produce suboptimal plans (as expected); and you are (more...)

Event Histogram Metric and Oracle 12c

Topic: event histogram metric, a script and some related comments on collecting and displaying wait event latency histograms for Oracle performance troubleshooting.

Why: Latency histograms (and by extension wait event histograms) provide very useful information when troubleshooting performance for systems exhibiting response time with multi-mode distribution. In such cases average wait values are often not sufficient to understand the behavior of the system under study and histograms provide a finer level of details. A (more...)

edb360 taking a long time

In most cases edb360 takes less than 1hr to execute. But I often hear of cases where it takes a lot longer than that. In a corner case it was taking several days and it had to be killed.

So the question is WHY edb360 takes that long?

Well, edb360 executes thousands of SQL statements sequentially (intentionally). Many of these queries read data from AWR and in particular from ASH. So, lets say your ASH (more...)