In this chapter, we introduced four main areas to extend Hive's functionalities. We also covered three kinds of user-defined functions as well as their coding templates and deployment steps to guide the coding and deployment process. Then, we introduced HPL/SQL, which adds procedure-language programming to HQL. In addition, we talked about streaming to plug in your own code, which does not have to be Java code. At the end of this chapter, we discussed the available SerDe to parse different formats of data files when reading or writing data. After going through this chapter, you should be able to write basic UDFs and HPL/SQL, plug code into streams, and use available SerDe in Hive.

In the next chapter, we'll talk about security considerations.