Answered Questions

  • 1) Differences between DSS and OLTP.2) Explain Grouped cross tab.3) Define Surrogate key.4) What is IQD file.5) Expalin Reference cursor.


    • Nov 5th, 2012

    3.Surrogate key is a sequencer which is used to uniquely identify a row in a OLAP. This helps in implementing SCD Type 2 in data warehousing.


    • Apr 2nd, 2012

    1). Store historical data of an organization
    2). Data is used for BI/ business strategic decision

    1). Real time transactional data
    2). Data is used to have track of transaction details.

  • What is surrogate key ? Where we use it explain with examples?

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    Answered by: saravanan

    • Dec 2nd, 2005

    Surrogate key is a unique identification key, it is like an artificial or alternative key to production key, bz the production key may be alphanumeric or composite key but the surrogate key is always single numeric key. Assume the production key is an alphanumeric field if you create an index for this fields it will occupy more space, so it is not advisable to join/index, bz generally all the datawarehousing fact table are having historical data. These factable are linked with so many dimension table. if it's a numerical fields the performance is high


    • Oct 29th, 2017

    Surrogate key is system generated key. It is a column or set of columns declared as primary key instead of real of natural key.

    Anukul Thawarey

    • Aug 8th, 2017

    Just to add on to this point, we can also have date stamp as in the format (yyyymmdd) which is actually an 4 Byte unsigned integer to keep track of the historical data. This date stamp column can also be considered as an surrogate key.