At PrestoCon Day, Anant Aneja of Ahana, an IBM Company introduced a new feature for Presto called Quick Stats which aims to enhance query optimization by providing up-to-date statistics for the query optimizer. This enables more accurate cost-based decisions and better selectivity for non-trivial queries. In this blog post we’ll recap the details and benefits…
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…