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what are relational and multi-dimensional format? RRS feed

  • Question

  • I read an interview question:
    "In which format SSAS stores data?"

    Well, I remeber having read, that ROLAP stores and operates their data and metadata in  relational format (OLTP relational database) that permits to use SQL, above of only MDX for SSAS storage.

    What are exactly relational  and multi-dimensional (SSAS) formats?
    What are details of their storage, resp., and what are the differences? 
    • Edited by vgv8 Friday, December 3, 2010 1:27 PM
    Friday, December 3, 2010 3:01 AM

Answers

  • Hi,

    Relational is two dimensional storage but under covers you have pages and extents.

    Regarding multidimensional storage I would describe that as a cobweb net where the dimension members are the threads and the interaction points of the threads are the measures. Mathematically it can be described as matrix storage.

    http://en.wikipedia.org/wiki/Matrix_(mathematics)

    HTH

    Thomas Ivarsson

    • Marked as answer by vgv8 Friday, December 3, 2010 1:22 PM
    Friday, December 3, 2010 12:23 PM

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