Occasionally one might want to know what a segment is made of in terms of block types. For example, you notice that the number of blocks in an index segment is somewhat larger than the number of branch and leaf blocks, and wonder what kind of blocks accounts for the difference. The only way to do this is by dumping index blocks (e.g. as described in Richard Foote’s blog here). Dumping blocks is easy, but (more...)
Voor maart hebben we twee interessante bijeenkomsten gepland bij bol.com.
Docker Meetup – Deep dive into Docker storage drivers
Op 5 maart hosten we voor de tweede keer een Docker Meetup in Utrecht. De presentaties worden verzorgd door:
- Jérôme Petazzoni (Senior Engineer Docker)
- Kay Davenport (Developer Evangelist ClusterHQ)
Inschrijven kan hier.
GOTO Night: Elasticsearch
Op 25 maart hosten we voor een GOTO night over Elasticsearch. Sprekers zijn:
- Anne (more...)
Why PerfSheet4: PerfSheet4 is aimed at querying and displaying time-series data from AWR repository tables. This is very a rich source of information to analyze database workloads and trends in the context of performance analysis or (more...)
Sonatype Nexus is an often used artifact repository. In a previous blog post I have shown an example how Maven can be used to assemble and release artifacts to Nexus. In this blog post I will describe two ways how artifacts can be fetched from the Nexus repository; by using the REST API and by using Apache Ivy.
The Nexus API
Sonatype has done a great job at providing an extensive well documented REST API. (more...)
- New Version Of XPLAN_ASH Utility - In-Memory Support: Informationen zur neuen Version, die insbesondere die CPU-Nutzung von In-Memory-Operationen ausweist.
- Video Tutorial: XPLAN_ASH Active Session History - Introduction: das Tutorial (18 min) stellt die zentralen Funktionen des Tools vor.
- Video Tutorial: XPLAN_ASH Active Session History - Part 2: (more...)
- info Funktion: ein erweitertes DESC, das nicht nur die Spaltendefinitionen, sondern auch Informationen zu den Indizes und Constraints einer Tabelle liefert. (more...)
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 bol.com.
To prove my point I’ve checked the release notes of Netflix and Spotify apps. Here (more...)
The 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...)
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...)
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
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:
Userspace probing is a very powerful technique that can be used to complement the available (more...)
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...)
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...)
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...)
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...)