A nice article on few DW worst practices.

Top Ways How Not To Scale Your Data Warehouse

I got this one from Tom Kyte’s blog. Thanks Tom.

(There were issues with the design in my original post. Those have been corrected. I have let the errors stay and have highlighted where I have made corrections so that you can understand better)

Consider this situation.

2 new guys Ravi and Raj go to our bank and open new savings accounts 101 and 102. And Ravi deposits 100 and Raj deposits 144. This can be represented by the following.

CLICK ON THE IMAGES BELOW TO SEE A LARGER PICTURE

Now suddenly, Ramu and Ramya come to the bank and open a joint account 103. And they deposit 1000. How will you represent this? What will you enter for CUST_KEY ? Will you enter 3 or 4? It was the same transaction of Rs 1000. But which customer to indicate? What will you fill in the red ? position below?

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I have written a post on my other blog about folder structures to effectively store project artifacts.

Please visit this link to access the same.

Also, please do not forget to leave a comment if you think you have a better idea.

Recently we migrated an entire DW module from Oracle to DB2. And our ETL was done using Business Objects Data Integrator.

Below is a sequence of steps that we followed to migrate the entire solution (including data structures, ETL code and universe)

Assumption:
–>All estimates done for 4 DB2 databases, 3 federated systems, 62 tables, 33 indexes, 6 DI jobs, 110 data flows, 151 transformations, 16 SQL transforms, 34 SQL() scripts, 220 objects in 23 classes and 2 reports.
–>Add 20% time as buffer for unexpected issues.
–>Some tasks can be executed in parallel, while some have strong dependency on completion of previous tasks.

Work breakdown of migration and rough estimation:

1. Initiation & planning : 40 Hrs
Establish objectives and goals
Requirements gathering
Establish scope
Plan resources
Identify development environment

2. Assessment : 40 Hrs
Assess tool and technology needs
Assess and understand technical requirements
Establish technical guidelines
Finalize tools and development environment

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I am currently researching and learning more about IBM DB2.

We recently migrated a module from Oracle to DB2 without having a single DB2 resource. Most of it was done on a research, trial and error basis.

And we had some great learning experience.

I will share those experiences with you soon.

In the meanwhile, if you know some great DB2 resources or help sites, please do leave a comment.