Within all database systems there are tables that hold transactions or some type of data based on time. These transactions unfortunately build up over time to handle regulatory compliance, infrequent access or support development of historical and trending reports.
Within your database design, this time-based transaction data builds up quickly and managing it so the volume does not affect performance is critical. Sometimes the frequency or grain of transactions such as web clicks, banking transactions, stock transactions or other transactions build up to terabytes of data per day, quickly overwhelming robust storage arrays.
Separating out the real time transaction data versus the old data within your database requires planning and design steps. These planning and design steps help the separation of the old data versus new data and guarantee application and SQL performance does not suffer when your database is fully populated A separation of the old and new data also helps performance management so more resources can be delegated to maintain transaction performance for business operational success.
DB2 10 Temporal Tables with their built-in functionality automatically understand the business time or system time that the data was entered into the system. This functionality is great for finding out the condition of the business as of a certain time. There are two new BUSINESS_TIME and SYSTEM_TIME table period definitions columns available. These new time period column definitions are used for the new DB2 temporal table definitions to provide system-maintained, period-maintained or bi-temporal (when both system and period maintained) database tables.
Many systems today have manual applications or utilities which migrate their real time data to history tables. These new temporal tables with their built-in system and business time columns can be used in conjunction with a user-defined trigger to automatically migrate transactional temporal table data to another user defined HISTORY table. Having these facilities built into the database greatly improves regulatory compliance, operations and overall performance.
More information can be found on DB2 10 Temporal Tables and other DB2 10 features in the IBM White Paper: IBM DB2 10 for z/OS Beta -- Reduce Costs with Improved Performance.