Identify the Data Source Tables

You map the logical tables to the physical tables alias that you created in the physical layer of the semantic model. When creating a semantic model, you must know what data your business community needs and understand the available data sources that can aid in meeting those needs.

Identify the following contents of the physical data source. To gather the needed information, work with a database administrator for each data source. To understand all of the data elements, ask the people who use or own the data, or the developers of the applications that create the data.

• Identify the contents of each table.

• Identify the detail level for each table.

• Identify the table definition for each fact table. This lets you set up the aggregate navigation. The Oracle Analytics query engine requires the following:

  • The level of aggregation for each dimension that the fact is joined with, for example is this table by day, by month, or by year.

  • For each measure defined on the fact, the type of aggregation: SUM, AVG, MIN, MAX, or COUNT.

• Identify the contents of each column.

• Identify the joins defined in the database.