Soocs is an independent Oracle database consultancy that focuses on the Oracle database technology stack. It is located in Germany and operates throughout the whole world - nowadays mainly in Europe and the USA. Based on my deep knowledge and understanding of the Oracle database core, I usually start where others quit.
Don't just take my word for it - see for yourself and check out my blog, publications and client reviews.

Silver bullets may be appropriate for hunting werewolves but not for fixing Oracle database or application performance issues.

I am your reliable partner for mission critical issues or “must not fail” projects and always up to go the extra mile with you. I keep the focus on your needs and issues without wasting time by playing political games. This level of expertise has never been so affordable, so flexible or so easy to acquire. All services are provided under confidentiality agreements.

Oracle Database & Application Performance

Oracle Database & Application Performance

All of my performance services are based on a systematic and scientific performance analysis approach called "Method-R" - an end user response time based performance improvement method that yields maximum economic value to your business and enables reliable performance forecasts.

Based on this method my advanced Oracle performance tuning service consists of top-notch database, application (PL/SQL or client-side code) and SQL statement analysis including cost based optimizer (CBO) troubleshooting, logical and physical data model design, application instrumentation, benchmarking of scalability and optimizing operating system (primarily AIX, Linux and Solaris) configuration for Oracle database systems. Based on my long-time experience with SAP on Oracle I provide specialized Oracle database services for SAP like performance analysis and tuning of SAP systems, SAP applications and R3load based migrations.

I also conduct client-specific performance tuning workshops or public online trainings.
Oracle Database & Operating System Troubleshooting

Oracle Database Internals & Operating System Troubleshooting

My troubleshooting services tend to analyze, fix or at least provide a work-around for Oracle RDBMS core problems or operating system (primarily AIX, Linux and Solaris) integration issues.

Since years I spend a lot of time researching and debugging the Oracle RDBMS core with GDB, DTrace or SystemTap and you can easily benefit from this rare internals knowledge in business critical situations like shared pool issues, sporadic memory leaks, general memory issues, unexpected ORA errors, unpredictable I/O behavior, database crashes with core dump, a stuck database and many more.
I help you to understand the corresponding Oracle core component, isolate the root cause, create an isolated and reproducible test case (for Oracle support if needed) or research your specific issue from the scratch.

I also conduct client-specific Oracle internals workshops or public online trainings.

Would you like to know more about my services or do you have a question about an issue that you have?
Please get in contact directly. I am usually available in short-term.

About Me & Company


My name is Stefan Koehler and I am an independent Oracle database consultant and the founder of Soocs.
I started my career with an "IT specialist / system integration" apprenticeship in 2001 and completed successfully 3 years later as one of the best in my year. Afterwards I worked as a classic *nix admin (primarily focusing on IBM AIX and Linux) and Oracle DBA for round about 2 years before I joined the SAP area with the main focus on Oracle databases and SAP performance tuning. In 2011 I founded my own company Soocs to provide independent and specialized consulting services for Oracle database performance tuning and internals troubleshooting in mission critical environments.

Since more than 15 years I follow my passion about Oracle and specialized in Oracle performance tuning and troubleshooting, especially in Oracle cost based optimizer (CBO) and database internal related topics. I am not just interested into understanding how an Oracle database feature works, but also how it is implemented in detail. In consequence I research a lot of Oracle database internals for education purpose or on client’s needs. In addition Oracle High Availability and Oracle Backup and Recovery are completing my skill set.

Nowadays I primarily work as an independent Oracle database performance consultant and researcher in large mission critical environments (e.g. +10 TB databases, +4000 concurrent users, etc.) for market-leading companies or multi-billion dollar enterprises in various industries all over the world. I usually support my clients in understanding / solving complex Oracle performance issues and troubleshooting nontrivial database issues on very short-term contracting basis.

I constantly share my experiences, findings and knowledge with the Oracle and SAP community through my blog and my activity on Oracle-L, Oracle technology network, SAP community network and Twitter. Sharing knowledge is one of my key aspects when working with clients or interacting with the community. I am also one of the leading contributors on the SAP community network in the "SAP on Oracle" area and I received awards by SAP for being the #1 SCN Topic Leader (2012/2013) – SAP on Oracle and #2 SCN Topic Leader (2013/2014) – SAP on Oracle.
In 2015 I received the greatest honor in my professional career as I was invited to join the well-known OakTable network, an informal organization of Oracle experts around the world, who believes in better ways of administering and developing Oracle based systems. I am also recognized and rewarded as an Oracle ACE by Oracle's ACE program.
Stefan Koehler

Contact & Tax Information

  •  Stefan Koehler
  •  Spessartstraße 2, DE-97249 Eisingen, Germany
  •  +49 (0) 172 / 1796830
Clients & Reviews
The following list is just an extract of my clients due to particular confidentiality agreements - especially with my US clients. Please contact me for more detailed information.

Stefan is a genuine Oracle database expert with in-depth knowledge and understanding of database internals and optimizer. He is able to efficiently work out a straightforward solution to all kind of different problems around the database, even complex performance bottlenecks, hanging issues and system crashes. If you need a quick solution for an urgent issue with an Oracle database, he is a right consultant to hire.

Nenad Noveljic

Head Databases and Middleware Engineering & Support, Bank Vontobel AG


Date Time Training title Details & Purchase
Tuesday, June 13, 2017 3:00 PM to 7:00 PM (CEST) Online class: Advanced Oracle internals & troubleshooting - Shared Pool Details about past event
The purchasing and billing process of my trainings is handled by my partner which provides world-wide payment with almost every option.
The training itself is organized and conducted by myself of course.

Public Appearances

When Where Event Talks
September 26 - 27, 2019 Zurich, CHE Trivadis Performance Days 2019 Troubleshooting with Oracle's Kernel Debug, Diagnostics and Tracing Infrastructure
January 11, 2019 Online DOAG Database Webinar Wo ist Walter? Die 0x Memory Leak Edition
November 20 - 22, 2018 Nuremberg, DEU DOAG 2018 Conference Oracle's kernel debug, diagnostics & tracing infrastructure
September 7 - 8, 2018 Sopot, POL POUG Where is Waldo? The 0x memory leak edition - Published by Geek Press
June 12, 2018 Vienna, AUT AOUG 2018 Conference Under the hood of dynamic and adaptive database features
June 11, 2018 Munich, DEU Regional DOAG group meeting Under the hood of dynamic and adaptive database features
March 15, 2018 Nuremberg, DEU Regional DOAG group meeting Under the hood of dynamic and adaptive database features
November 21 - 23, 2017 Nuremberg, DEU DOAG 2017 Conference Under the hood of dynamic and adaptive database features
October 19, 2017 Nuremberg, DEU Regional DOAG group meeting Researching the Oracle core - 3 slides and a lot of internals hacking fun
October 3, 2017 San Francisco, CA, USA Oak Table World 2017 Lightning Talk - Troubleshooting & Fixing Long #PARSE Calls In 10 Minutes
September 1 - 2, 2017 Krakow, POL High Five POUG Researching the Oracle core - 3 slides and a lot of internals hacking fun in 45 minutes
February 27 - March 2, 2017 Dallas, TX, USA Hotsos Symposium 2017 Troubleshooting Oracle performance issues beyond Oracle wait interface
Hacking Oracle's memory - About internals & troubleshooting
November 15 - 18, 2016 Nuremberg, DEU DOAG 2016 Conference Hacking Oracle's memory - About internals & troubleshooting
October 20, 2016 Nuremberg, DEU Regional DOAG group meeting Hacking Oracle's memory - About internals & troubleshooting
September 28 - 29, 2016 Zurich, CHE Trivadis Performance Days 2016 Troubleshooting Oracle performance issues beyond Oracle wait interface
June 16, 2016 Nuremberg, DEU Regional DOAG group meeting Troubleshooting Oracle performance issues beyond Oracle wait interface (Extended Version)
November 17 - 20, 2015 Nuremberg, DEU DOAG 2015 Conference Identifying performance issues beyond Oracle wait interface