Showing posts with label data sub-setting techniques. Show all posts
Showing posts with label data sub-setting techniques. Show all posts

Friday 22 February 2013

Techniques for Data Subset

In my previous posts, I explained about Data Subset in TDM & Implementation Approaches to Data Sub-setting.  In this post, I will explain some basic techniques with the help of which we can do a data subset.

  • First N records
    • This is a pretty simple technique, wherein the first N records of a table is retrieved from the Production database.  This can be achieved using a simple SQL Query such as
      • SELECT TOP 10000 * FROM DBO.CUSTOMERS
  • Based on a filter criteria
    • This is a scenario where the subset conditions can be based on a simple filter criteria like Age > 50, City = London, etc.  This is easier to implement in cases where the subset requirements are less complicated.  An example query for such technique would be
      • SELECT * FROM DBO.CUSTOMERS WHERE AGE > 50 AND CITY = 'LONDON'
  • Based on a complex SQL query
    • Sometimes the subset requirements can be more complicated.  It might involve dependencies across multiple tables.  What that means is