“show slave hosts” on master not reporting hostname

If you have multiple MySQL slaves or complex topology, its difficult to remember what slaves are replicating from which master.

We can go to slave servers and check “show slave status” which list master host, but if we want to find out other way, we have can run “show slave hosts” from master.
This will list down all the slaves that are getting replicated from this master.

Only problem I faced was, “show slave (more...)

Ruby Thin Web Server

Somebody suggested that I try out thin, “A fast and very simple Ruby web server.” So, I thought it might be interesting to test, and a simplification over Rails to demonstrate an small Ruby MVC pattern.

Installing thin seemed straight forward as a gem installation, like

gem install thin

The initial install didn’t work out of the box because I’d neglected to install the gcc-c++ library. It raised the following errors:

Fetching: eventmachine-1. (more...)

Find a string in files

From time to time, folks ask questions about how to solve common problems in Linux or Unix. Today, the question is: “How do I find a list of files that contain a specific string?” There are two alternatives with the find command, and the following sample searches look for files that contain a sqlite3 string literal.

  • Search for only the file names:
find . -type f | xargs grep -li sqlite3

Or, the more verbose:

Searching Oracle Service Bus Pipeline Alert contents

There are several ways monitor messages passing through the Service Bus. Using pipeline alerts is one of them. Pipeline alerts can be searched in the Enterprise Manager based on several parameters such as summary or when they have occurred. Usually an important part of the message payload is saved in the content of the alert. This content can not be searched from the Enterprise Manager. In this post I will provide an example for logging (more...)

ODM : View Transformations generated by Automatic Data Prepreparation

A very powerful feature of Oracle Data Mining and one that I think does not get enough notice is called Automatic Data Preparation.

Data Preparation is one of the most time consuming, repetitive and boring parts of the work that a Data Miner or Data Scientist performs as part of their daily tasks. Apart from gathering the data, integrating the data, getting the data into the required formation the most interesting part of the work (more...)

Ruby-MySQL Columns

Last week I posted how to configure and test Ruby and MySQL. Somebody asked me how to handle a dynamic list of columns. So, here’s a quick little program to show how to read the list of column:

require  (more...)

Java-MySQL Program

It turns out that configuring Perl wasn’t the last step for my student instance. It appears that I neglected to configure my student instance to support Java connectivity to MySQL. This post reviews the configuration of Java to run programs against MySQL. It also covers the new syntax on how you register a DriverManager, and avoid Java compilation errors with the older syntax.

In prior posts, I’ve shown how to use Perl , PHP (more...)

Upgrading to Application Express 5.0 in Your Oracle Database Release 12.1 Multitenant Container Database (CDB)

Woo hoo! Oracle Application Express 5.0 has been released. Read all about it here.

The purpose of this blog post is to provide information on how to upgrade your 12.1 Multitenant Container Databases (CDBs) to APEX 5.0, and specifically ones where you have Oracle Application Express installed in CDB$ROOT (the root), and you are making use of Oracle Application Express 4.2.x in the PDBs in this CDB. There has been (more...)

Monitoring PPR Request Time on ADF UI Client Side

We can measure how long it takes to process request on the server side, however it is equally important to measure how long PPR request takes on the client side. Mainly because this will be a key factor for application performance exposed to the end user. There is relatively easy approach in JSF 2.0 to measure PPR request time on client side - with a special ajax tag. ADF 11g R2 and ADF 12c (more...)

ASM Rebalance Too Slow? 3 Tips To Improve Rebalance Times


I’ve run into a few customers recently who have had problems with their ASM rebalance operations running too slowly. Surprisingly, there were some simple concepts being overlooked – and once these were understood, the rebalance times were dramatically improved. For that reason, I’m documenting the solutions here… I hope that somebody, somewhere benefits…

1. Don’t Overbalance

Every time you run an ALTER DISKGROUP <NAME> REBALANCE operation you initiate a large amount of I/O workload as (more...)

JSON for APEX Developers (part 3): Querying JSON in Oracle DB 12c

In previous blog posts I talked about JSON for APEX Developers:
In this post I want to show how you store and query JSON data straight in the database.

To start, create a table to store the JSON object:

    date_loaded (more...)

Tips on Submitting an Abstract to Conference

<.. The tech15 committee and my role
<…. Who plans the Tech15 content

The call for Papers for UKOUG Tech15 has gone out. This is how most of the content for a large conference is sourced, by asking the community to submit abstracts for consideration. With smaller conferences and user group meetings the organisers can often get enough talks by hassling asking people they know.


Firstly, I would encourage anyone who has considered talking at (more...)

How To Use The Docker 1.6 Windows Client

Newest Docker 1.6 release was pushed yesterday. Normally, no reason to go crazy, but this time I think, it's worth a blog. Because, it finally contains the first Docker Client for Windows. If you hated having to ssh into your instance and having to do everything via boot2docker: This is over now.
You can download official distribution of Docker Client for Windows by either installing it from the Chocolatey package manager (which I never (more...)

APEX 5: forgot the images?

On my play environment I usually use Oracle APEX with the Embedded PL/SQL Gateway, just because it's so easy.
When a new version of APEX is released, just like everybody else, I upgrade my play environment.
After the apexins.sql script is run, I always want to start playing with it immediately. Usually it is at this point where I just see a blank page... scratching my head wondering why it is not running,... having (more...)

Goldengate Data Manipulation – When Inserts & Updates differ

One very useful aspect of Golden Gate is to allow the manipulation of data between the source and the destinations.

One recent problem that I encountered was to alter the data differently for inserts than for updates. This was caused by the receiving system needing to have some default data in columns which may or may not be supplied by the insert or update statements. This is slightly more complex than first imagined:

Table Functions (Steven Feuerstein)

Wenn ich an PL/SQL denke, ist meine erste Assoziation dazu der Name Steven Feuerstein. Nun denke ich nicht furchtbar oft on PL/SQL, aber wenn der Herr Feuerstein über ein Thema schreibt, dem ich mit einer gewissen Regelmäßigkeit begegne, dann ist das allemal eine Verlinkung und Zusammenfassung der zugehörigen Artikel wert:

Kwaliteit in dienstverlening is een zaak van perceptie

Kwaliteit in dienstverlening is een zaak van perceptie. Het gaat over voldoen aan verwachtingen. Het imago van een organisatie, verhalen van referenten, persoonlijke informatie-uitwisseling met account managers en de inhoudelijk betrokkenen spelen allemaal een rol. Deze elementen in combinatie met persoonlijke ervaringen vormen een verwachtingspatroon. Een verwachtingspatroon dat bij iedere stakeholder anders is. Net zoals de wijze waarop de uitvoering van de dienstverlening wordt ervaren. Daarbij komt dat verwachtingen niet altijd expliciet worden uitgesproken of (more...)

Oracle Priority Support Infogram for 16-APR-2015

Time to Patch!

From the Oracle E-Business Suite Technology blog:


From OTN DBA/DEV Watercooler: Oracle APEX 5 Is Here


SOA Suite 12c: Topology Suggestions, from the SOA & BPM Partner Community Blog.

Data Integrator

Data Integration Tips: ODI 12.1.3 – Convert to Flow

The many who have already upgraded Oracle Data Integrator from the 11g version to 12c probably know about this great feature called “convert to flow”. If not, well…here you go!

First, a little background on why I think this is an excellent bit of functionality. The ODI Upgrade Assistant will convert objects from 11g to 12c and it does a pretty decent job of it. When converting Interfaces, the upgrade process creates a Mapping in ODI 12c by taking the (more...)

My first experiences with ThreadLogic

A while ago I came into touch with ThreadLogic. Most of the people whom I was talking about it, did not know the tool. This unfamiliarity with ThreadLogic made me decide to write this blog. I think that every WebLogic Administrator should know ThreadLogic and that it is also a very interesting tool for Fusion Middleware Developers.

But let me start at the beginning. A while ago Michael Sahadat, a SOA/Integration Architect at Oracle, came over to (more...)