Sunday, October 3, 2010

Dimensions of Data Extraction or Data Acquisition

Five Dimensions are generally used to describe the different methods and properties of data acquisition process.
1.Acquisition/Extraction Mode
2.Acquisition/Extraction Scenario
3.Acquisition/Extraction Formats
4.Data Latency
5.Acquisition Scope

Acquisition Mode:
The Extraction mode refers to the range of data extracted from the source system. Basically there are 2 types of Extraction Mode.
1. Full Extraction Mode
2.Delta Extraction Mode
Full Extraction mode extracts all data records available in the source tables based on the acquisition scope defined.
Delta Extraction Mode only reads updated or newly inserted records since from the previous data load.
From an sap bw point of view extraction mode is referred to as update mode.
Acquisition Scenario:
Data can either be pushed into a data warehouse or pulled from an operational system(source system). In a pushed scenario, the initiator of the data acquisition is the sender system or middle ware. The web services interface is an example of a push data acquisition,
In a pull scenario, the initiator of the data acquisition is the datawarehouse system. Eg:SAP BW. The file interface is an example of a pull data acquisition.

Acquisition Formats: Data can be file versus database, relational versus multi dimensional or XML Versus Text versus Binary. i.e., CSV,ASCII and Binary.

Data Latency: It refers to the timeliness of Data acquisition. Whether or not an acquisition is synchronous(realtime) Asynchronous( Stored and Forwarded) or Asynchronous Batch(Background).
In general these are called as V1,V2,V3 Updates.
Acquisition Scope: It refers to the specification of how data must be acquired from a projection(which fields), a selection(which records are required) and an aggregation(at what level of granularity perspective)

1 comment:

  1. Hello,

    Data Extraction is the act or process of retrieving data out of data sources for further data processing or data storage. It holds the dimension data while it is being updated. Thanks a lot....