ACFS 12.2 Quirks with defragmentation

I have a 12.2 RAC cluster in my lab, on two virtual machines. Checking out what acfsutil can do, I figured out that it can supposedly do defragmentation:

[grid@rac1 ~]$ acfsutil defrag -help

Usage: acfsutil [-h] command ... # (Version

-h - help

Command Subcmd Arguments
--------------- --------- ------------------------------------------------------
 defrag dir [-r] <path>
 defrag dir Defrag all files in a specific directory 
 defrag dir [-r] recursively traverse directories
 defrag dir  (more...)

SecureFile LOB – move online in 12.2

Today we had a "new features in 12.2" workshop. Thank you Mathias Zarick for this great event.
One of the new features was Online Table Move. But the doc was quite unspecific if this also includes LOBs:
Nonpartitioned tables can be moved as an online operation without blocking any concurrent DML operations. A table move operation now also supports automatic index maintenance as part of the move.
Data maintenance on nonpartitioned tables does not (more...)

WebLogic Server – First Look

Since last night the latest release of the Oracle WebLogic Server is available.

I have already installed and configured the latest release, the installation process remains the same as in the previous release, so nothing really new.

The Configuration Wizard ($ORACLE_HOME/oracle_common/common/bin/ got a new cool neat feature. On the screen 2 of the Configuration Wizard (Templates), you will find a Filter Templates option. In this Filter Templates you can (more...)

Oracle Fusion Middleware available

Since today the latest release of the Oracle Fusion Middleware Stack is available for download under Oracle Technology Network.

The latest release of the Fusion Middleware Stack contains various products:

Oracle WebLogic Server can be found under

Oracle Forms & Reports can be found under

Oracle SOA Suite (more...)

Provide access to #WebLogic DMS Spy Servlet for readonly users

For security reasons and to prevent the configuration drift it is recommendable to use read only for analyzing problems.

For read only access of configuration and logs WebLogic provides out of the box the group Monitors. Unfortunately you cannot access DMS Spy Servlet with this group, which is useful for analyse runtime values of the server. Only users which belongs to the Administrators group and therefore have full access can access DMS Spy Servlet and (more...)

Apache Spark and CERN Open Data Analysis, an Example

This is a short post introducing a notebook that you can use to play with a simple analysis of High Energy Physics (HEP) data using CERN open data and Apache Spark. The idea for this work started with a concept for a technology demonstrator of some recent developments on using modern tools for data analysis in the context of HEP. The actual analysis used in the final version comes from previous work published by the  (more...)

Parallel Reality

"Expect everything, I always say, and the unexpected never happens."
-- Norton Juster, The Phantom Tollbooth

The following question was recently posted in an Oracle forum:

hi Friends,
I see  this wait event latch: parallel query alloc buffer, when a job meant for doing some cleanup ran this query.
Why does this wait event come happen? , i searched google,MOS no exact hit for explanation of the exact same event.
Looking at query does  (more...)

Create a Custom Authentication and Authorization Scheme in Oracle APEX

This post is part of a series of posts: From idea to app or how I do an Oracle APEX project anno 2017

Before when creating the APEX application based on a Blueprint, we used the standard APEX Authentication, which means the management of users is done in Oracle Application Express itself. As we created our own user table, we want to manage our users there and have some custom authentication scheme for our multiplication (more...)

Apache Spark for High Energy Physics Analysis, an Example

This is a short post introducing a notebook that you can use to play with a simple analysis of High Energy Physics (HEP) data using CERN open data and Apache Spark. The idea for this work started with a concept for a technology demonstrator of some recent developments on using modern tools for data analysis in the context of HEP.

PayWay interface

This is just to document how my system (which was built quite a few years ago) handles credit card payments via PayWay. The interface is rather dated and the way my system uses it is a bit hackish but for what it’s worth:

Step 1. On the server, generate a unique transaction reference, e.g. id123456

Step 2. On the server, request a token via HTTP Post:

Data (all one line):


Infosys, NRN Murthy, and Vishal Sikka – No One’s Smelling of Roses


orporate sagas seem to come in twos. The mega-fracas that erupted in 2016 between Cyrus Mistry, then Chairman of Tata Sons, and the iconic Ratan Tata, Chairman Emeritus at Tata Sons,  was starting to come to a close by the second half of 2017 (though I fear the last words have yet to be written). Ratan Tata had annointed N Chandrasekaran, CEO of TCS, as thew Chairman of Tata Sons, (more...)

Hadoop for Database Professionals – St. Louis (7. Sep)

Here’s some more free stuff by Gluent!

We are running another half-day course together with Cloudera, this time in St. Louis on 7. September 2017.

We will use our database background and explain using database professionals terminology why “new world” technologies like Hadoop will take over some parts of the enterprise IT, why are those platforms so much better for advanced analytics over big datasets and how to use the right tool from Hadoop ecosystem (more...)

How to speed up your Oracle Data Mining with in-memory and parallel

Have you have found running a workflow in Oracle Data Miner slow or running the scripts in the database slow ?

No. Good, because I haven't found it slow.

But (there is always a but) it really depends on the volume of data your are dealing with. For the vast majority of us who aren't of the size of google, amazon, etc have data volumes that are not that large really and a basic server can (more...)

The amazing ANSI join syntax quirk

| Aug 28, 2017
The kind of quirks I love: those that you can find a workaround for without having to wait for a patch.I am talking Oracle Database 12c Enterprise Edition Release - 64bit Production running on some unix flavor (I ignore which flavor, I've no access to the unix box).You execute the following query and it f.cuaa,f.id_fgra, d.id_cons, c.id_part, p.id_prt,        

RAC 12.2, part 2

Well, today was an interesting day. My ASM, configured with so much effort, stopped working:

root@rac1 grid]# . ~grid/.bashrc
[root@rac1 grid]# crsctl start ohasd
CRS-4640: Oracle High Availability Services is already active
CRS-4000: Command Start failed, or completed with errors.
[root@rac1 grid]# crsctl start cluster
CRS-2672: Attempting to start 'ora.crf' on 'rac1'
CRS-2672: Attempting to start '' on 'rac1'
CRS-2676: Start of 'ora.crf' on 'rac1' succeeded
ORA-27140: attach to post/wait facility failed

Adding flexibility to your PostgreSQL clusters – Using EDB Failover Manager

Using PostgreSQL in enterprise environments gets more and more popular. And why not? This extremely stable and performant database can compete with ease with almost all enterprise database installations out there today.

Competing technically? Sure!
Competing from a business perspective? Absolutely!!

Making sure your database systems stay up during planned maintenance? Absolutely yes, no discussion about that!
Ensuring your systems stay up during a catastrophic failure of your master? Yes! We need to ensure 99. (more...)

Hands-on 5 week Sunday workshop for Oracle 12c RAC, ASM and Clusterware

My friend and fellow Oracle Certified Master Gavin Soorma is offering this five week online workshop on Sundays, which looks very interesting for people seeking to learn about these advanced Oracle technologies. 

This online training workshop will help you build your own personal two-node Oracle 12c Release 2 Real Application Cluster environment and learn in-depth about Oracle 12c RAC, ASM and Clusterware Administration.

The five week, 20 hour online workshop commencing on Sunday, September (more...)

RAC 12.2

I am in the process of installing RAC 12.2. The installation procedure has undergone a significant change, for the better. It’s now much easier to install it. However, memory and disk requirements have skyrocketed. I needed to allocate 10GB of memory for each of my nodes, 12 GB for OCR and 64GB for the management database. My computer will be barely large enough to run both Commserve and those two nodes together:


I am (more...)

Display Oracle Forms 12c Sessions with WLST

Sometimes you want to get a quick overview of the current connected Forms Sessions in your Oracle Forms 12c environment and the Fusion Middleware Control (http://<servername>:7001/em) is sometimes really slow reacting.

Under the My Oracle Support (MOS) Note 1580517.1 you can find a small handy Python Script, which should display you all informations about your current Forms Sessions against a specific Managed Server hosting your Forms Application. But with Oracle Forms 12c (more...)

Educational Eclipse

Last night around midnight I laid in bed hoping that thousands of people on the other side of the world took the opportunity to experience the once in a life time experience that would be a total solar eclipse.

If you agree that a wonderful piece of prose can help recreate the experience, I recommend this literary non-fiction from 1982 by Annie Dillard.

Today I'd like to share three things I learned about the solar (more...)