Presto, a prominent open-source distributed SQL query engine, has been at the leading edge of high-performance data analytics for over a decade. In analytical data processing, the effectiveness of query optimization is paramount. Over the last half-century, optimizing SQL queries has been a hotbed of research and development, resulting in groundbreaking innovations. This blog post…
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…