Migrating SQL workloads from a fully on-premise environment to cloud infrastructure has numerous benefits, including alleviating resource contention and reducing costs by paying for computation resources on an on-demand basis. In the case of Presto running on data stored in HDFS, the separation of compute in the cloud and storage on-premises is apparent since Presto’s…
In the previous article we looked at the abstract problem statement and possibilities inherent in scanning tables. In this piece we look at the quantitative upside with Presto. We look at a number of queries and explain the findings. The initial impulse motivating this work is the observation that table scan is by far the…
Table scan, on the face of it, sounds trivial and boring. What’s there in just reading a long bunch of records from first to last? Aren’t indexing and other kinds of physical design more interesting? As data has gotten bigger, the columnar table scan has only gotten more prominent. The columnar scan is a fairly…