Prerequisite : the content of this page is a continuation of Imperative Squall interface and is based on the concepts detailed in it. Theta-Join concepts are presented in the publication from A. Okcan and M. Riedewald Processing Theta-Join using MapReduce [1] and briefly described in our Squall overview.
This section is divided into two parts. The first part describes how query plans using Theta-Join can be written, more specifically how join conditions are specified, as it is the main difference compared to the standard hash-join. The second part provides explanation on how Theta-Join is implemented in Squall.