• 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.

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    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.