Functions defined as SECURITY DEFINER are a powerful, but dangerous tool in PostgreSQL. The documentation warns of the dangers: Because a SECURITY DEFINER function is executed with the privileges of the user that owns it, care is needed to ensure that the function cannot be misused. For security, search_path should be set to exclude any […]

  PostgreSQL commit 74dfe58a5927b22c744b29534e67bfdd203ac028 has added “support functions”. This exciting new functionality that allows the optimizer some insight into functions. This article will discuss how this will improve query planning for PostgreSQL v12. If you are willing to write C code, you can also use this functionality for your own functions. Functions as “black boxes” […]

PostgreSQL offers powerful means to manage users / roles and enables administrators to implement everything from simple to really complex security concepts. However, if the PostgreSQL security machinery is not used wisely, things might become a bit rough. This fairly short post will try to shed some light on this topic. The golden rule: Distinguish […]

Years ago Years ago I wrote this post describing how to implement 1-to-1 relationship in PostgreSQL. The trick was simple and obvious: You put a unique constraint on a referenced column and you’re fine. But then one of the readers noticed, that this is the 1-to-(0..1) relationship, not a true 1-to-1. And he was absolutely […]