Routines

Routines are pieces of code or programs that you can call to perform operations.

• Stored procedures
  A procedure (often called a stored procedure) is a program that can be called to perform operations that can include both host language statements and SQL statements. Procedures in SQL provide the same benefits as procedures in a host language.
• Use user-defined functions (UDFs)
  In writing SQL applications, you can implement some actions or operations as a UDF or as a subroutine in your application: Although it may appear easier to implement new operations as subroutines in your application, you might want to consider the advantages of using a UDF instead.
• Triggers
  A trigger is a set of actions that are run automatically when a specified change operation is performed on a specified table or view. The change operation can be an SQL INSERT, UPDATE, or DELETE statement, or an insert, update, or delete high-level language statement in an application program. Triggers are useful for tasks such as enforcing business rules, validating input data, and keeping an audit trail.
• Debug an SQL routine
  By specifying SET OPTION DBGVIEW = *SOURCE in your Create SQL Procedure, Create SQL Function, or Create Trigger statement, you can debug the generated program or module at the SQL statement level.
• Improve performance of procedures and functions
  When creating stored procedures and user-defined functions (UDFs), the SQL procedural language processor on the iSeries™ does not always generate the most efficient code. However, you can do some changes to reduce the number of database engine calls needed and improve performance.