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Data Integrity

Protecting your data is a vital concern, and this topic encompasses different concepts. First, you don’t want users to enter illegal values. So, you want to check or validate new data before it gets to the database. The tutorial touched on some of the ways you can validate data, like validation expressions in the database or database triggers. On a lower level, you can use triggers in your interface to check data as the user enters it. To learn more about validation, see both the Progress Database Design Guide and the Progress Programming Handbook .

Next, if you begin to write a set of changes to a database, you need to make sure that either the whole set is written to the database or the whole set is not written. Incomplete database writes can cause database corruption, incomplete data, or conflicting data.

A set of data slated for writing to the database is known as a transaction. A transaction may be interrupted by some user actions or system errors. Progress has many valuable default behaviors that commit or roll back transactions in response to interruptions. Understanding when Progress starts and ends transactions and how Progress decides to commit or roll back transactions is very important for mission critical applications. See the Progress Programming Handbook for this information.


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