Daniel Westermann

Why does my first tablespace in PostgreSQL always get the OID 16384?

For those already familiar with this topic and wonder about the heading, hold on and continue reading. One of the exercises we do in our PostgreSQL DBA Essentials workshop is to create a tablespace. This is to(…)

How to efficiently add constraints to existing tables in PostgreSQL

Is is not a surprise that applications change over time. New tables get added, columns need to be changed or new ones are required, and sometimes you need to add check constraints or foreign keys to already existing tables which(…)

PostgreSQL indexes and operators

Creating a standard B-tree index in PostgreSQL is nothing special and usually we do it without thinking about what happens in the background. For the standard data types like e.g. int or text we do not need to know anything(…)

Some basics about time zones in PostgreSQL

As soon as you have an application which works across time zones you will have to deal with that properly in the database. I've seen many applications that didn't care of that at the beginning, and much work had to(…)

In which order do triggers fire in PostgreSQL?

When you are working with triggers it might be important to know in which order they fire. Of course, a "before" triggers fires before an "after" trigger. But what happens if you have two or more triggers for the same(…)

How much shared memory is PostgreSQL using? (2) – details

In the last post in this two post series we've briefly looked at configuring huge pages on Linux for PostgreSQL. It became clear, that calculating the number of huge pages purely based on the setting of(…)

How much shared memory is PostgreSQL using? (1) – basics

Have you ever wondered if the value of shared_buffers is the only setting which controls how much shared memory PostgreSQL is actually using? There was a nice addition committed to PostgreSQL 15 recently, which helps in answering(…)

Temporal tables for PostgreSQL 15?

One of the features which is currently missing in PostgreSQL is Temporal Tables. Other database systems have that since a long time and many people want to have in PostgreSQL as well. If you don't know what it is,(…)

Parallel distinct for PostgreSQL 15

When parallel execution was introduced with PostgreSQL 9.6 it was quite limited and supported only a few operations to run in parallel. Over time more and more operations were enabled to run in parallel. When PostgreSQL 15(…)

What are those *_init files for in PostgreSQL?

Quite some time ago I've written about relation files in PostgreSQL and when they get created. In that post we talked about the files containing the actual data, the free space map (fsm) and the visibility map(…)