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Huge table meets star schema

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Huge table meets star schema Empty Huge table meets star schema

Post  ObjectiveC Wed Apr 27, 2011 5:34 pm

Hello everyone,

I have a general question.

I was wondering if it's acceptable to combine a star-schema with one or more huge table(s). Where those huge tabels would be a plain dimension like dim_huge_x and a fact_table would be just a fact_table.

So I was thinking of a design like this:

dim_date -> fact_table
dim_time -> fact_table
dim_person -> fact_table
dim_huge_x -> fact_table
etc...


What are your thoughts on this ?

ObjectiveC

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Join date : 2011-03-18

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Post  ngalemmo Wed Apr 27, 2011 5:38 pm

I don't follow... do you mean to say derive a big flat dimension by denormaling all related dimensions into one table... creating a schema made up of one fact and one dimension table?

I wouldn't do that... performance would be terrible.
ngalemmo
ngalemmo

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Post  ObjectiveC Thu Apr 28, 2011 2:19 am

ngalemmo wrote:I don't follow... do you mean to say derive a big flat dimension by denormaling all related dimensions into one table... creating a schema made up of one fact and one dimension table?

I wouldn't do that... performance would be terrible.

I mean derive a big flat dimension by denormaling some dimensions, not all. So that way you will have a normal star schema, but with one or two big flat dimensions.

ObjectiveC

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Post  ngalemmo Thu Apr 28, 2011 8:37 am

It really depends. If you mean creating a junk dimension for a handful of low cardinality codes and descriptions, fine.
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