PostgreSQL Archives - Blog dbi services

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 about operators or operator classes. In those cases the standard operator class for the data type is applied and all is fine. But sometimes we need to know about the possibilities PostgreSQL comes with, and…

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 be done to change the implementation afterwards. The one and only recommendation is: Do it properly from the beginning and you don’t have to think much about it in the future. PostgreSQL comes with all…

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 event? Maybe you want to make sure that a specific trigger is executed first (for whatever reason) or you want to make sure that another trigger is executed last. The good news is: You can…

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 shared_buffers will not work. PostgreSQL requires more shared memory, but what exactly is it? Well, this is the goal of this post and I’ll introduce a new feature of PostgreSQL 15 which helps in identifying those bits without digging…

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 this question (more on that later). shared_buffers for sure is the biggest chunk of shared memory that PostgreSQL is using but there might be other factors which come into the game. You might ask yourself why that is…

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, here is a short overview. Basically you can ask for a row as it was at a specific point in time. The patch which implements this, is currently in status “Ready for Committer”, which does not…

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 will be released next year it will come with parallel distinct. Here is an easy example:

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 (vm). But this is not all, there is another kind of file you might spot if you take a look into the directory of a database.

This script provides functionality to setup passwordless authentication in PostgreSQL for defined Server Names. This is very helpful by using replication via repmgr and is not Linux Distribution specific, it was used till now with SLES 12, SLES 15 and RHEL 8 Clones. As all of my scripts it provides help how the usage is with -h parameter: $ [[[email protected] ~]$ sh pgpass.sh -h $ [[[email protected] ~]$ Usage: $ [[[email protected] ~]$ pgpass.sh [OPTION] $ [[[email protected]…