Understanding hash joins in Redshift query plan

[dylanbaker]

This is awesome. Makes complete sense. Thanks!

(Has prompted another question relating to the efficient way of joining on inequalities. I’m going to ask that in another post.)

How to create efficient timeseries models (or how to join efficiently on inequalities)

Somewhat inspired by @drew’s great answer to this question about hash tables: What we currently do We need to report on the state of various records as of the end of every day, based on Type 4 history tables created by our Django application. For example, this could be the facility limits of each of our borrowers on a daily basis. Currently, our models take the following steps: Build a daily timeseries model. We build this as a utility table in our production schema as we use it in multipl…