© Kevin Feasel 2020Kevin FeaselPolyBase Revealedhttps://doi.org/10.1007/978-1-4842-5461-5_4
4. Using Predicate Pushdown to Enhance Query Performance
Durham, NC, USA
In Chapters 2 and 3, we looked at using PolyBase to retrieve data from Azure Blob Storage and Hadoop, respectively. In both of those cases, we allowed the PolyBase data movement service to pull all of the data from our external data source and then applied filters and performed aggregations within SQL Server. This is our only option for Azure Blob Storage, but when working with Hadoop, there is another technique: predicate pushdown. This chapter will dive into the concept of predicate pushdown and look at the mechanisms available in PolyBase to offload compute requirements ...