STAR and SNOWFLAKE Schema
STAR Schema
Consists of one fact
table that is surrounded by dimension tables. It is an easy to understand structure.
How it works to give
results?
A query made on this structure
can easily combine results from various dimensions linked to the fact table and
result the required data required to answer any user question. Relationship of
a record in a fact table is with the rows present in the dimension tables.
Example:
SNOWFLAKE Schema
This is the Normalized version of STAR Schema.
All the tables present as dimensions here are normalized. The Fact table remains the same as STAR Schema.
It holds an advantage of
less storage space and being a normalized structure it is easy to update and
maintain. Thus, for a database that changes frequently this structure is
preferred.
Example:
No comments:
Post a Comment