MaxCompute provides SQL computational function for users. You can use System Built-in Functions in MaxCompute SQL to complete computation or count. But when the built-in functions are unable to meet the requirements, you can use Java to delevelop user defined function UDF. The user defined function (UDF) can be further divided into scalar valued function (UDF), user defined aggregation function (UDAF) and user defined table valued function (UDTF).
After UDF coding is finished, the code needs to be compiled into a jar package and uploaded to MaxCompute. While using UDF, you only need to specify the function name of UDF and input the parameters.The use method is the same as built-in functions provided by ODPS.
- For function operations, refer to Function Introduction.