A histogram is a chart that shows frequencies for equal width intervals of values of a metric variable. A company wants to know how monthly salaries are distributed over 1,110 employees having operational, middle or higher management level jobs. The screenshot below shows what their raw data look like.
The snowflake schema is a variation of the star schema, featuring normalization of dimension tables. In computing, a snowflake schema is a logical arrangement of tables in a multidimensional database such that the entity relationship diagram resembles a snowflake shape. The snowflake schema is represented by centralized fact tables which are connected to multiple dimensions..
Snowflake Schema versus Star Schema comparison chart; Snowflake Schema Star Schema; Ease of maintenance / change: No redundancy, so snowflake schemas are easier 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: Lower query complexity and easy to understand