Quick tips to troubleshoot the first installation of Pentaho BI 5.0.1 CE with MySQL

Last week, I successfully installed Pentaho BI Server Community Edition. It wasn’t as easy as I expected. I did follow a really good tutorial from David Fombella at http://anonymousbi.wordpress.com/2013/12/15/pentaho-bi-server-5-0-1ce-mysql-installation-guide/  Like many people, I did have the famous 404 error. It’s not a big deal, there is no error that can’t be explained with the log files, right ?

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Consider the following as an extension of the tutorial

Tip #1

Be careful at step #5 and don’t forget to delete tomcat/conf/Catalina/localhost/pentaho.xml . Keep in mind that every time you modify tomcat/webapps/pentaho/META-INF/context.xml, pentaho.xml has to be deleted because it’s an exact copy of context.xml.

Tip #2

Don’t copy/paste the configuration provided in the tutorial for pentaho-solutions/system/jackrabbit/repository.xml  (Step #6) because the CLASS attribute of the all the nodes is missing ! The XML file already has examples that you can copy past with all the nodes and the proper attributes.

Pentaho.xml is not the only config file that is duplicated. I spent HOURS searching the node with the missing class attribute  in JackRabbits’s repository.xml (yup, I did copy paste from the tutorial..). I ended up reverting all my modifications and I still had the missing class error in the log file, over and over.  The fact is: if you do start pentaho with the missing class attribute in repository.xml, it will create a folder named pentaho-solutions/system/jackrabbit/repository/ which seems to have generated/copied files based on the configuration. The problem is it generates a file with a missing class attribute ! It took me too long to realize pentaho-solutions/system/jackrabbit/repository/ IS NOT PART OF THE DEFAULT INSTALLATION. It’s generated. If you screw up the config like me, DELETE THE ENTIRE FOLDER.

Tip #3

Another thing you have to know is about the folders tomcat/work/Catalina and tomcat/temp. Both folders contain temporary file that can be removed. But the folders themselves must exist! For an unknown reason, my tomcat/temp folder was missing and that prevents Jackrabbit to start properly with the not-so-useful error:


So, if you are getting problems with the installation like many people, including myself have, just execute this every time you change a config file. It will allow to start with a clean environment.

I hope it could save you time !

Oh! One last thing..don’t try to run it on a 1Gb RAM server.. it won’t work. :)



How to search for a specific column in all Oracle schema

As an ETL developer, this is something I have to do when developers of a source database application have to extend the length of a field. Because that field can be used in so many different projects and/or datamart, I need to find all the possible tables and views of all schemas having the field in my database.

Here is how I do it.. Suppose i’m looking for a column named “awesome_id”.  All I have to do is to execute this query with a user having the privileges to read into all schemas.

It will return all the tables having a column with the word “awesome_id”.

But it didn’t look the queries used to build views. Instead I have to use:

Unfortunately, it only returns the first 4000 characters of the queries, but the lookup is done on the complete queries.

This WordPress blog runs on MariaDB

Recently, my hosting company Funio has replaced MySQL for MariaDB on their shared hosting infrastructure. Some friends working there told me they get better performance with MariaDB than their previous MySQL installation.

MariaDB is a drop-in replacement of MySQL. This WordPress blog was first installed with MySQL, and suddenly and automagically runs on MariaDB. As a DBA, I was excited to use all the new features… but I realized that I’m pretty limited on Funio’s database infrastructure since I’m just a simple user…! So, just for fun, I changed the engine of all my tables to ARIA.  It’s the least I can do.

ARIA is a crash-safe alternative to MyISAM and according to plans, it will become Transactional in the next major release. I don’t expect it to be as fast, reliable and robust than InnoDB (or XtraDB.. the altered version of InnoDB developed by Percona and included in MariaDB), but it’s definitely a good “hybrid” solution between MyISAM et InnoDB.

I didn’t experience issue since the changes, so if you are a WordPress user, don’t be afraid to give it a try !