Data Warehousing Basics Question: Download Questions PDF
Explain Differences between star and snowflake schemas?
Answer:
star schema is a logical structure that can be arranged with fact and dimension tables
in a star formation.it looks like a star with fact table at the core of the star and the dimension tables along the spikes of the star.the dimension model is therefore called a STAR SCHEMA.
SNOWFLAKING is a method of normalizing the dimension tables in a star schema.
Star Schema: can have less number of joins.
Snow flake: can have more number of joins.
Star Schema : has data redundancy, so the query performace is good.
Snow flake: is normalized, so does not has data redundancey. can have perfomance issues.
in a star formation.it looks like a star with fact table at the core of the star and the dimension tables along the spikes of the star.the dimension model is therefore called a STAR SCHEMA.
SNOWFLAKING is a method of normalizing the dimension tables in a star schema.
Star Schema: can have less number of joins.
Snow flake: can have more number of joins.
Star Schema : has data redundancy, so the query performace is good.
Snow flake: is normalized, so does not has data redundancey. can have perfomance issues.
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