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MattiasThalén
Partner - Contributor II
Partner - Contributor II

Smallest performance footprint between duplicated rows vs extra relation

Hi!

I have two solutions for a model and am trying to decide on which would have the smallest performance footprint:

  1. [Order Fact (10M): %ItemKey] > [Item Dim (1M): %ProductGroupKey] > [Product Group Dim (100k)]
  2. [Order Fact (10M): %ItemKey] > [Item Dim (1M): %ProductGroupKey]
    + [Order Fact (10M): %ItemKey] > [Product Group Dim (1M)]

Basically it stands between having a snowflake or a star schema, an extra relation, vs duplicating data in [Product Group Dim] so I can join it directly to [Order Fact].

My gut tells my that having that option 1 has the smallest footprint on performance.

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1 Reply
Chanty4u
MVP
MVP

You are correct that having option 1 with a snowflake schema is likely to have a smaller performance footprint than option 2 with a star schema.

 

In a snowflake schema, the fact table is connected to dimension tables through intermediate tables, resulting in a more normalized data structure. This can help to reduce data redundancy and improve data consistency, which can lead to faster query performance.