Periodic snapshot analysis

    Periodic snapshot analysis

     

    There are only 3 categories of fact table [ref. Kimball: transaction, periodic snapshot & accumulating snapshot].  The analysis of periodic snapshot tables is straight forward, as long as the analysis recognizes that the facts are only "semi-additive".

     

    There seems to be relatively little available on the Community relating to analysis of periodic snapshots, so I have put together an example.

     

    Any analysis of a periodic snapshot requires to reference the "snapshot period" (census [measurement] date) {see: comment about semi-additive nature}, and this can be achieved in one of two ways:

    • As Of Date calendar & Analysis Flags; or
    • Set Analysis.

    There are advantages and disadvantages of each approach, and you may find yourself more comfortable with one than the other.

     

    I tend to adopt the Set Analysis approach and I'd welcome any thoughts on the relative benefits.

     

    Explore & Enjoy,

    Nick Scott.