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Hi,
Can you please tell me which schema is best for Fast loading data?
Dear Muthukumar,
Kindly check the attached image for Star Schema vs Snowflake Schema. I hope this will help you to understand in better way.
For more information, please have a look into listed below similar thread
Re: Star & snowflake schema
Kind regards,
Ishfaque Ahmed
Hi muthukumar,
Please refer to the page 15 from this document Best Practices for Data Modelling, it's a good reference of the advantages and disadvantages of a snowflake vs a star schema. In my personal opinion, I strongly support the Star Schema model, it provides not only better performance but also it's easier to understand for the user. I also recommend to read some of the Kimball techniques for dimensional modeling.
Hope it helps,
-- Karla
Dear Muthukumar,
Kindly check the attached image for Star Schema vs Snowflake Schema. I hope this will help you to understand in better way.
For more information, please have a look into listed below similar thread
Re: Star & snowflake schema
Kind regards,
Ishfaque Ahmed
Hi Muthukumar,
Star Schema is the best loading technique.
Snowflake Schema | Star Schema | |
---|---|---|
Ease of maintenance / change | No redundancy and hence more easy to maintain and change | Has redundant data and hence less easy to maintain/change |
Ease of Use | More complex queries and hence less easy to understand | Less complex queries and easy to understand |
Query Performance | More foreign keys-and hence more query execution time | Less no. of foreign keys and hence lesser query execution time |
Type of Datawarehouse | Good to use for datawarehouse core to simplify complex relationships (many:many) | Good for datamarts with simple relationships (1:1 or 1:many) |
Joins | Higher number of Joins | Fewer Joins |
Dimension table | It may have more than one dimension table for each dimension | Contains only single dimension table for each dimension |
When to use | When dimension table is relatively big in size, snowflaking is better as it reduces space. | When dimension table contains less number of rows, we can go for Star schema. |
Normalization/ De-Normalization | Dimension Tables are in Normalized form but Fact Table is still in De-Normalized form | Both Dimension and Fact Tables are in De-Normalized form |
Data model | Bottom up approach | Top down approach |
The main difference between star schema and snowflake schema is that
Can anybody explain why Single Table is bad for RAM Consumption and Script Run Time?