To answer this question, you need to understand the concept of OLAP cubes and their metadata.
OLAP (Online Analytical Processing) cubes are multidimensional data structures that are used for analyzing and reporting data. They provide a way to organize and summarize large amounts of data into a format that is easy to understand and analyze.
The metadata of an OLAP cube refers to the information about the cube's structure, dimensions, measures, hierarchies, and relationships between the different elements. This metadata is essential for querying and analyzing the data in the cube.
The source of an OLAP cube's metadata can come from different places, but the most common sources are star schema and snowflake schema.
A star schema is a type of database schema that organizes data into a central fact table surrounded by dimension tables. The fact table contains the measures or numerical data, while the dimension tables contain the descriptive attributes or dimensions. In this schema, the metadata for the OLAP cube can be derived from the star schema.
A snowflake schema is a more complex version of the star schema, where dimension tables are further normalized into sub-dimension tables. In this schema, the metadata for the OLAP cube can be derived from the snowflake schema.
Therefore, the correct answer is C) Both a and b. The metadata of an OLAP cube can be sourced from both star schema and snowflake schema, as they provide the necessary structure and relationships for the cube's dimensions and measures.