Ans: There are two methods to load the data in dimension tables. Following are the two methods:
- Conventional(Slow): Before storing the data into the dimension table, all constraints and keys are legalised against the data, and this process is called data integrity which is a time taking process.
- Direct(Fast): In this process, all constraints and keys are disabled before loading the data into the dimension table. Once loading of the information is complete into the dimension table, it validates the data against constraints and keys. In this process, if any set of data is invalid or irrelevant, then the information is skipped from the index and all future operations.