Indexes on fact table

  • hi

    my fact table consist of 4 dimensions. I have a composite primary key on all the 4 dimensions. the time dimension is of 15 minutes and it is one of the dimensins. i have one more date column says just the date without 15 minutes just to tell which date it is.

    it has been designed already and now i can't remove the other date column. and it has been used in reports and other queris.

    my question is to speed up the activity should i create an index on the same?

    Thanks,

    Regards,

    Ami

  • Which data column did you want to remove exactly?

    And which column do you want to speed up?

    Typically, indexes will enhance query performance, if created correctly.

    Need an answer? No, you need a question
    My blog at https://sqlkover.com.
    MCSE Business Intelligence - Microsoft Data Platform MVP

  • As a rule of thumbs it should be an index per each dimension pointing to a specific fact table.

    Remember that the function of the dimensions is to provide the means to slice-and-dice the measures stored in the fact table therefore a sound indexing strategy is a must.

    A single index on all dimensions would help only queries using all dimensions to filter/acces the data - which is not usually the case.

    _____________________________________
    Pablo (Paul) Berzukov

    Author of Understanding Database Administration available at Amazon and other bookstores.

    Disclaimer: Advice is provided to the best of my knowledge but no implicit or explicit warranties are provided. Since the advisor explicitly encourages testing any and all suggestions on a test non-production environment advisor should not held liable or responsible for any actions taken based on the given advice.

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