Rafia Sabih - PostgreSQL Executor: Executing your execution plan (PGConf.EU 2024)

In PostgreSQL, one of the key components is its query executor which is really in charge of running your query. This presentation will deep dive into this vital component of PostgreSQL and shed some light on the inner workings of the very heart of PostgreSQL. Let us understand how PostgreSQL really runs a query, how data is processed and which key internal algorithms and data structures are at work to make PostgreSQL tick. How does PostgreSQL handle expressions? What is an executor state and how does PostgreSQL actually execute an execution plan created by the optimizer? Where does parallelism kick in?