Showing posts with label techniques for data subset. Show all posts
Showing posts with label techniques for data subset. 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