Mario Talavera Writes

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Archive for the ‘Data Warehousing’ Category

Installing Oracle DB 12c in Linux OEL6 (In One Sitting)

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Because I will have to do this again in no time, here I jot down the quickest way for me to install 12c.  This is the usual series of following steps, running into an error, searching for a fix, lather, rinse repeat.

Step One – Install oracle-rdbms-server-12cR1-preinstall.

Source – http://www.oracle.com/technetwork/articles/servers-storage-admin/ginnydbinstallonlinux-488779.html.

Step Two – …gets us all the way here – [FATAL] PRVF-0002 : Could not retrieve local nodename

Source -  http://www.krenger.ch/blog/fatal-prvf-0002-could-not-retrieve-local-nodename/

Step Three -  … cannot write oradata change to /home/oracle/oradata

Source – http://blog.ronnyegner-consulting.de/2009/09/14/oracle-11g-release-2-install-guide-%E2%80%93-grid-infrastructure-installation/

Step Four – Swapfile … I used 10000

Source – https://community.oracle.com/thread/2189824?tstart=0

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Step Five – Then I see installer is bent on putting oradata directory in /home.  Just revise to suit your install.

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Presto!

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Written by mariotalavera

April 30, 2014 at 8:10 pm

Posted in Data Warehousing, SQL

OBIEE Reporting From Transactional Databases

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This blog post is about OBIEE reporting.  Specifically, it is about skipping the data warehouse and reporting from the transactional database instead.  Oracle’s OBIEE, like most BI reporting tools, is designed to use star/snowflake schemas as the underlying structures to report from.   Additionally, OBIEE’s metadata layer is very rich and extensively well thought out, allowing for a great deal of flexibility.  Oracle’s metadata tool (Admin Tool) allows us to leverage this flexibility and features to bridge the gap between an OLTP and an OLAP model.  I am not negating the need for a data warehouse, I am just wondering if all BI reporting projects merit one.

So the question to ask is: Is OBIEE up to the task?

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Written by mariotalavera

June 4, 2013 at 7:12 am

Flex OLAP Cube – updated

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I’ve added ability to consume URLs whose output is XML as a data-source for Flex OLAP Cube. Check it out :)

Going thru this exercise has helped me understand a bit about creating data cubes and the uses they serve. This is but one of the many interesting (to me) things I am exposed to at work. Doing this from scratch provides me with insight unattainable with a ‘shrink-wrap’ tool.

Note – I had originally fetched data from accross the web but had to store xml files internally for show and tell. Enjoy.

Written by mariotalavera

September 30, 2010 at 2:31 am

Movielens OLAP Cube Slicing And Dicing On Demand

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I wanted to write the post ‘Slicing Your Own OLAP Cube’ but I am not there yet. From my last post, a recurring theme in my friends comments was that the dimensions and measures that can be inspected where set in stone. I thought I was doing fairly well but I can see their point. Having a cube and having it sliced in a way you don’t need is kinda useless.

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Written by mariotalavera

September 28, 2010 at 12:17 am

Movielens – Movie Ratings Analysis with OLAP Cubes

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For this post, I will describe how to use the previously provided database to create data cubes from the Movielens Dataset.  With these cubes, I will then create a few reports using Adobe Flex to illustrate the advantages of using data cubes for reporting instead of the more traditional ‘query and report’ practices from live databases, etc.

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Written by mariotalavera

August 23, 2010 at 4:25 pm

Movielens OLAP – Database Download – updated

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UPDATE -
1. I have broken down mysql dump file to a set of individual files per table. I got some complaints on unreasonable file size.
2. I’ve now included 10 million movie ratings as well which I hadn’t because of size as well. Now its a file to itself and you can skip if you find it difficult to import.

I’ve finally gotten around to posting the database online to share. This olap database is a star schema of movie ratings and movie topic tags as described on previous posts (here and here).

The set can be downloaded from Infochimps here. I will post any updates there as well.

Written by mariotalavera

August 16, 2010 at 11:33 am

Real Time Dashboards 3 – Backend

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For a quick refresh, just go back to the intro post where we state what we intend to do.

Or do this instead and get up to speed faster.  All components are linked to for if you do not have the software we’re using…

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Written by mariotalavera

May 26, 2010 at 2:53 am

Real Time Dashboards 2 – update

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Oops,  missed a field in log create script on my previous post.

You can pick proper file here -> log-revised-sql.  Create script fir step table is fine, file is here -> step.sql.

After running these two scripts (remember to rename to ‘.sql’), you should have the following tables in your database:

Next time, we’ll be setting up the Java part of the application…

Written by mariotalavera

May 22, 2010 at 2:55 pm

Real Time Dashboards 2 – SQL layer

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This is part 2 of Real Time Dashboards. Reading the previous introductory post (it is short) will put this post in context.

As previously mentioned, our monitor checks up on an ETL process which is itself updating many databases as it executes.

For this post series, we are going to randomly grab an existing workflow (thank you Mazda) to monitor. We will be monitoring a ’100-point’ car inspection. Lets imagine a car inspector checking things off in his tricorder or some other digital device. This device is, of course, running a program that records everything to a simple database.

I know, one would actually wait in a lobby while technicians check a car out. Feel free to swap my workflow with your workflow; the point to take from this is that our monitor will work well regardless the process being monitored :)

Hoping to keep this part basic, I am constructing a table called Step with the following fields: id, label, parentId, workEffort. WorkEffort will be a numeric field, a hypothetical amount of work each respective step would take (could define time, hammers to the head, amount of cowbell, etc.). This basic structure will allow the definition of any number of main and sub processes in a tree hierarchy. This table can be used to describe any number of main steps, each with any number of sub steps. It is important to note that we would be assigning ‘workEffort’ values to the children of our main steps for as many levels as we may have. I.E. – only the children of these steps (the inner steps) will have workEffort… Aggregating these values would, in turn, yield the workEffort of its parent. Peachy.

We will have a second table, Log, where the status of each of these processes can be recorded. The log table will have the following fields: id, active, success, startTime, endTime. Both active and success will be booleans and will indicate which process is active and which process, if any, fails.

Simple but complete enough to represent many real life processes we could monitor. At work, our typical process consists of a series of main steps each comprised of many sub steps. The tables described here would even allow us to take this a bit further as long as we remain sensible in our expectations on performance and complexity.

I have included the scripts to create each of these tables step and log for you. Download and replace the doc extension for sql. WordPress, free and wonderful, wouldn’t allow me to upload .sql files. Bah!

For the next post I will be describing this ‘car inspection’ process and how we can both model and mimic realistically.

Written by mariotalavera

May 17, 2010 at 1:51 am

Real Time Dashboards 1 – Introduction

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Based on my presentation at BarCamp Orlando 2010, I’ve decided to do a series of posts generalizing my work.  Hopefully this will help me remember the skills used and, more importantly, help someone else in turn.

The dashboard built for my presentation consisted of an Adobe Flex application as the front end, a Java backend and BlazeDS (Adobe’s as well) in the middle to connect these two.  I had developed a tech demo for work where this tool would provide real time operational insight into the progress of a long running task.  More specifically, this operational dashboard would relay progress, realtime, on an Extract, Transform and Load (ETL from now on) job we needed to monitor.

This ETL job is a combination of java tools and different databases where data is extracted, then curated and then processed to be reused in different ways.  It’s a thing of beauty in execution but a bit intimidating to someone like me who lacks a thorough understanding of what I do for a living :)

I thought it would be nice to build a tool to monitor on this process.  It would have to be non intrusive to my team or to ETL, and had to be completely independent of the tool it was keeping tabs on.  Thinking this would be a fun way to use Flex and BlazeDS (I miss working with Flex), I set out to built such a tool.  Unbeknownst to be, the task would prove to be bit more complicated than I thought it would be (ignorance keeps me bold).  In the end, some of the most daunting requirements where easily met with a completely free set of tools and the end result was not bad looking either.  it even works!

I used quite a few tools to complete a working example and will try to break posts down into main components that can be completed independently.  Feel free to stay tuned (or not) for the juicy parts. Hopefully, I can at least save you some time showing you what not to do.

Briefly, the dashboard was constructed with the following technologies, all freely available:
For the software parts, Abode Flex (ActionScript 3), Java and Hibernate.
For the server components, I used Tomcat and Adobe BlazeDS. Oh yeah, you are going to need a database server of your choice.  I will be using MySQL.
Any text editor would do as well; I am most comfortable in Eclipse but you may use anything you want.

Written by mariotalavera

May 10, 2010 at 5:01 pm

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