This topic describes the built-in functions and user-defined functions (UDFs) that MaxCompute provides.

MaxCompute provides SQL computing capabilities. You can use the built-in functions in MaxCompute SQL statements to complete some computing and counting tasks. If the built-in functions do not meet your requirements, you can use the Java APIs that MaxCompute provides to develop UDFs.

UDFs can be classified into scalar-valued functions, user-defined aggregate functions (UDAFs), and user-defined table functions (UDTFs).

After you develop a UDF, you must compile the UDF code to a JAR package, upload the package to MaxCompute as a resource, and then register the UDF in MaxCompute.
Note To use a UDF in MaxCompute, you only need to specify its name and parameters in an SQL statement as you do when you use the built-in functions of MaxCompute.

For more information about how to manage functions, see Create a function, Delete a function, and List functions.