Daniel Westermann

PostgreSQL 17: login event triggers

This is a feature I am sure a lot of people have waited for and finally it was committed for PostgreSQL 17. Back in my Oracle days it was quite common to have a trigger firing once a user logged(…)

PostgreSQL 17: Support for AT LOCAL

When it comes to conversions between time zones in PostgreSQL, there is already much you can do today. What PostgreSQL up to version 16 does not support, is the conversion to the local session’s time zone with ‘AT LOCAL’. Starting(…)

How the name of the initial superuser is chosen in PostgreSQL

When working with a PostgreSQL instance, most of the time the initial superuser is called “postgres”. One might think this is always the case, and this user is there by default. But the name for that user is chosen by(…)

Things you can, but probably shouldn’t do in PostgreSQL: Tables in tables, types in types, and arrays on top

PostgreSQL comes with a lot of flexibility for defining new data types, defining tables and defining arrays over data types. You can make that as complex as you want, which does not mean that you should do it. Somehow you(…)

No more snapshot too old in PostgreSQL 17

Currently PostgreSQL has a feature which is called snapshot too old. While each release of PostgreSQL comes with a bunch of new features, sometimes features also get removed. Starting with PostgreSQL 17 there will be most likely no more “snapshot(…)

“create user”, “create role”, what should be used in PostgreSQL?

Recently we’ve seen a video on YouTube which recommends not to use the “create user” command in PostgreSQL and instead always use the “create role” command. It was also mentioned that “create group” should not be used as well. We’ve(…)

PostgreSQL 17: Allow “\watch” to stop based on the number of rows returned

psql already is really powerful but still it gets more features with almost every release of PostgreSQL. One example is the “\watch” meta command. This command was introduced in PostgreSQL 9.3 and hasn’t changed much since(…)

PostgreSQL 17: pg_wait_events

As development of PostgreSQL 17 already started there are already some commits which bring in new functionality. One of them introduces a new catalog view called “pg_wait_events”. As the same implies, this view lists the known wait events for PostgreSQL.

PostgreSQL 16: Playing with pg_stat_io (2) – evictions

In the last post in this little series we’ve looked at the “extends” statistic in pg_stat_io. In this post we’ll look at the “eviction” statistic. Before we go into the details: What(…)

PostgreSQL 16: Playing with pg_stat_io (1) – extends

PostgreSQL 16 (currently in beta 2) will come with a new view for tracking I/O related statistics. I’ve written a very basic blog about pg_stat_io in the past. In this post and(…)