Nikolay and Michael discuss PostgreSQL subtransactions — what they are, and four issues they can cause at scale.  Here are some links to things they mentioned: Subtransactions (docs) https://www.postgresql.org/docs/current/subxacts.html   SAVEPOINT (docs) https://www.postgresql.org/docs/current/sql-savepoint.html   PostgreSQL Subtransactions Considered Harmful (blog post by Nikolay) https://postgres.ai/blog/20210831-postgresql-subtransactions-considered-harmful   Subtransactions and performance in PostgreSQL (blog post by Laurenz at Cybertec) https://www.cybertec-postgresql.com/en/subtransactions-and-performance-in-postgresql/   Notes on some PostgreSQL implementation details (blog post by Nelson Elhage) https://buttondown.email/nelhage/archive/notes-on-some-postgresql-implementation-details/  Why we spent the last month eliminating PostgreSQL subtransactions (GitLab blog post) https://about.gitlab.com/blog/2021/09/29/why-we-spent-the-last-month-eliminating-postgresql-subtransactions/   ~~~ What did you like or not like? What should we discuss next time? Let us know via a YouTube comment, on social media, or by commenting on our Google doc! ~~~ Postgres FM is brought to you by: Nikolay Samokhvalov, founder of Postgres.ai Michael Christofides, founder of pgMustard With special thanks to: Jessie Draws for the amazing artwork