Summary

In this chapter, we covered how to aggregate data using basic aggregation functions. Then, we introduced advanced aggregations with GROUPING SETS, ROLLUP, and CUBE, as well as aggregation conditions using HAVING. We also covered the various window functions. At the end of the chapter, we introduced three ways of sampling data. After going through this chapter, you should be able to do basic and advanced aggregations and data sampling in HQL. In the next chapter, we'll talk about performance considerations in Hive.