A database specialist is designing the database for a software-as-a-service (SaaS) version of an employee information application. In the current architecture, the change history of employee records is stored in a single table in an Amazon RDS for Oracle database. Triggers on the employee table populate the history table with historical records.
This architecture has two major challenges. First, there is no way to guarantee that the records have not been changed in the history table. Second, queries on the history table are slow because of the large size of the table and the need to run the queries against a large subset of data in the table.
The database specialist must design a solution that prevents modification of the historical records. The solution also must maximize the speed of the queries.
Which solution will meet these requirements?