Adding Intelligence to the Database Manager

You can write code to perform any of a range of functions:

• Calculate values at runtime

  For example, you might include database system code to read the current exchange rate and convert a total amount into another currency

• Implement additional integrity constraints

  For example, you can add code to ensure that a replacement is in stock before a material is deleted

• Implement views of the data

  For example, you might define an empty table named OVERDUE_ORDERS. At read time, your exit code would read the main orders table and return the records with overdue accounts

• Implement a sophisticated security system

  For example, you might make a table accessible to specific people at different times of the day

• Log database usage

  For example, you might maintain a file logging all reads of sensitive data