Star schemas consist of dimension and fact tables. Dimension tables consist of data in which the fact tables can be reported and summarized on. These are typically smaller parent tables. Fact tables hold the important statistical information in which business decisions can be made. The fact tables are larger than dimension tables and many of the fields are numeric and can be summarized.
Dimensions help make the fact table information meaningful.
Tables in the star schema are generally more de-normalized. De-normalized tables allow for easier and quicker reporting, because there are not as many joins and less complicated joins. In order to track the data a schema using start or beginning dates and ending dates can be used. This works by time stamping new records coming in and time stamping the old records. Another challenge in implementing a data warehouse is getting the data into the schema.