New address for the quattro research blog!

Dear readers!

Our blog has moved to a new address:

We hope that you enjoy the new design and look forward to your comments!

See you on the new blog,

your quattro research team

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Two employees of quattro research to participate in quarterly PL/SQL challenge playoff

At quattro research, we try to always keep up-to-date with new trends & technologies (especially regarding the Oracle database).

So, we are very proud to announce that two of our employees have qualified for the quarterly PL/SQL Challenge Playoff for Q 2013/03:

Frank Schmitt

Marco Erdmann

The PL/SQL Challenge offers Oracle technologists and PL/SQL developers a place “to hone their skills, deepen their knowledge of PL/SQL, SQL and APEX and have fun and win prizes along the way” – highly recommended.

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Sneak Preview: quattro/Workflow 4

We will release quattro/Workflow Version 4 shortly. The new quattro/Workflow 4 is a major upgrade with a lot of added functionality. This post will show some of them.

When starting quattro/Workflow 4 you will first notice the new user interface:


The user guidance is still the same but all menu items are now arranged in ribbons.

SQLite as primary data format

We spent most of our time on completely rewriting the data transformation modules in quattro/Workflow. In version 1-3 we used XML as our primary data format. While XML is a widely accepted standard for data exchange, it has also some drawbacks concerning performance and tool support. We now use SQLite as our primary data format in quattro/Workflow 4. SQLite offers more possibilities for data manipulation than XML and takes the performance of quattro/Workflow to a new level. In addition, SQLite is highly supported by a lot of tools and technologies.


Performance, memory optimization, flexibility

Together with the new data format  the performance for large datasets has been massively improved– quattro/Workflow 4 is faster and consumes less memory than the previous version. Even with standard desktop PCs, you are now able to analyze thousands of plates in short time. The flexibility of the new data format gives you more possibilities for your assays.

ELISA analysis

Besides improved analysis of initial HTS screening and dose-response experiments, quattro/Workflow has now a new standard assay protocol for ELISA experiments.


Standard curves are analyzed with the 4-parameter logistic (4PL) nonlinear regression model. Sample calculation and automatic limit of detection analysis will make your ELISA analysis easier than ever.

Office data format

quattro/Workflow 4 is now able to read and write the new XLSX data format of your Microsoft Excel documents.

New scripting interface

quattro/Workflow 4 gives advanced users the possibility to extend their analysis with the new Python scripting interface. Python is the industry standard for scientific data in the life science industry. You can write your own scripts, or we can easily provide you with tailor-made versions of quattro/Workflow. The possibilities of this scripting interface will be demonstrated in subsequent posts.


Taking together, we see this release as the most important improvement of quattro/Workflow through the years. If you want to participate in our beta testing program, please send a mail to weisser @

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APEX Listener 2.0.1 – Standalone usage

The new APEX Listener 2 offers a lot of advantages over the older version 1. Just to name a few:

  • Standalone version without an application server
  • Nice support for RESTful services

The installation is documented pretty well and can be found at

Another blog entry covers this installation.

After finishing the installation, I tried to start the listener stand alone:

D:\oracle\apex_listener.>java -jar apex.war standalone

After convincing the Windows firewall that I really want to do this, the APEX listener started.


Unfortunately after opening the browser, the only thing I saw was an empty page.

Some previous experiences with the listener (and some googling of course) pointed to the APEX images causing the problem. You can download them with the full APEX package:

Extract the package and copy the apex/images subfolder to a reasonable location. I selected C:\TEMP\apex\images

After this, restart the APEX listener with an additional switch:

java -jar apex.war standalone --apex-images C:\TEMP\apex\images

Hope this helps,


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