Monday, November 29, 2010

Operational Data Store Vs Data warehouse

Operational Data Store(ODS)

Data warehouse

ODS is an Online integration of data

Typically it won't provide online Information.  It provides offline  data.

ODS is used, when a system's data is required to access from some other systems immediately. Ex: records updated from various section, data is lying in different DB, of Hospital is required while billing or some other activities

It is used while making decisions from past and present data(bit old, may be data taken from hours or days back)

ODS is centralized repository of data for online operational use

This is Non-Operational use


What is Data warehouse?

Data warehouse is repository of data, which are collected from many sources like transactional database or old backup data, etc., and then filtered, cleansed, transformed the data for the purpose of analyzing, decision making and reporting.

Monday, November 22, 2010

Types Of Dimensions:

Dimensions are classified as followings:


1. Slowly Changing Dimensions or SCD (Type0,Type1,Type2,Type3,Type4,Type6)
2. Slowly Growing Dimensions or SGD (Type1,Type2,Type3 from SCD)


And Other Types are...


1. Conformed Dimension
2. Junk Dimension
3. Degenerated Dimension
4. Role Playing Dimension