User Defined Functions (UDFs) are extensions or additions to the existing built-in functions of the SQL language. It allows the user to extend the capabilities of the database by creating custom functions just like built-in functions. UDFs enhance modularity and code reuse, improves query readability by encapsulating complex logic, and optimizes performance by executing custom logic directly within the database. A UDF takes one or more columns or parameters as input. These inputs can be values from a table, constants, or expressions passed to the function. It then applies the logic or operations defined in its code to process the input. This logic can range from simple calculations to complex business rules, transformations, or validations. After performing the defined actions, the UDF produces an output, which is returned as a single value (for scalar UDFs) or as a set of rows (for table UDFs). This result can then be used directly in queries, enabling seamless integration into existing Db2 workflows or applications. We will also cover in this presentation the following topics: · Overview of User Defined Functions (UDFs) · UDF Types and Differences · Differences between UDF, Stored Procedure and Trigger · UDF Operations and Options · SQL Scalar UDF Ordering and Versioning · UDF Restrictions and Considerations · Real-World Use Cases of User Defined Functions
