Historical or auditing data is commonly produced automatically by database systems and does not require constraints to guarantee data integrity. In addition to this, it is usually in large data sets. Therefore, historical and auditing data can be a candidate for using the Stretch DB feature. SQL Server 2016 introduced support for system-versioned temporal tables. They are implemented as a pair of tables: a current and a historical table. One of the requirements for historical tables is that they cannot have any constraints. Therefore, historical tables used in system-versioned temporal tables are ideal candidates for stretching. Temporal tables are covered in Chapter 7, Temporal Tables.