Not sure if you have a more specific question but Drill basically relies on an abstraction that we call Value Vectors. Take a look at [1]. The whole execution relies on these columnar structs so no row-wise materialization is done.
1: https://drill.apache.org/docs/value-vectors/ -Hanifi 2016-05-18 20:34 GMT-07:00 Yijie Shen <henry.yijies...@gmail.com>: > Hi folks, > > I'm new to Drill and find > "Drill also provides an execution layer that performs SQL processing > directly on columnar data without row materialization" and "vectorization > in Drill allows the CPU to operate on vectors" on > https://drill.apache.org/architecture/ page. > > I'm really curious about how these are implemented in Drill, after some > search in the current code base, I could only find parquet files could be > read in as vectors, how are these vectors handled then in `vectorized` > manner? Could someone nicely point out where I can find more > information/code on this? > > Thanks in advance. > > Yijie >
