All Postgres Locks Explained | A Deep Dive

This episode explores the complexities of locking mechanisms in PostgreSQL, specifically focusing on the various types of locks and their interactions. The host, Hussein Nasser, initially intended to discuss a Notion blog post about sharding and Postgres limitations, but his lack of complete understanding of Postgres locking led him to delve into a deeper explanation of the topic. Against this backdrop, he examines different lock levels (table, page, row) and their nuanced behaviors, highlighting the counterintuitive nature of some lock names and their actual functionalities. More significantly, the discussion progresses to a detailed analysis of lock modes like access exclusive, access share, row share, and row exclusive, explaining their conflicts and implications for concurrent operations such as vacuuming, indexing, and data modification. For instance, the host clarifies the differences between `vacuum full` and `vacuum` and their respective lock acquisitions. Ultimately, this deep dive into Postgres locking provides valuable insights for backend engineers, particularly in understanding concurrency control and potential performance bottlenecks arising from lock contention.