Hello! I'm kicking off another article series about the internals of PostgreSQL. This one will focus on query planning and execution mechanics. This series will cover: query execution stages (this article), statistics, sequential and index scans, nested-loop, hash, and merge joins. Many thanks to Alexander Meleshko for the translation of this series into English. This article borrows from our course QPT Query Optimization (available in English soon), but focuses mostly on the internal mechani...| postgrespro.com
So far we have covered query execution stages , statistics , sequential and index scan , and have moved on to joins. The previous article focused on the nested loop join , and in this one I will explain the hash join . I will also briefly mention group-bys and distincs.| postgrespro.com