Database Administration & Monitoring

Locales, collations, encodings and the PostgreSQL sort order (1) – basics

When it comes to sorting strings it is all about locales and how PostgreSQL is using them. PostgreSQL uses the locales provided by the underlying operating system, by default this is “C” or “POSIX”. To see(…)

What is the difference between session_user and current_user in PostgreSQL?

When you want to know the currently connected user in PostgreSQL for your session there are two system information functions which seem to do the same thing. There is “session_user” and there is “current_user”. So what is the difference between(…)

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(…)

SQL Server: How to shrink the T-log file for a lot of old user-databases

Recently I have the case that a customer has a lot of databases not more used but need to be accessible at any time. In this case, we had a lot of T-log with the size when there are used(…)

New Features 23c, Overview (in extracts):

In this blog I want to introduce some of the new features of the Oracle 23c developer edition. It will be only a selection of some of the main features. It is not the intention to give you a thorough(…)

Oracle Lock Free Reservations

The Oracle 23c new feature Lock Free Reservations allows to break with the traditional locking mechanism. Now multiple concurrent sessions can update the same row without be blocked !!! Let’s see how it works. In the traditional locking mechanism,(…)

Automatic PL/SQL to SQL Transpiler

SQL is a wonderful language and very easy to use. For example you can call a PL/SQL function into a SELECT or WHERE clause and the result of the PL/SQL function is returned into the SQL expression. But when we(…)

SQL FIREWALL

This blog comes to complete the excellent blog written by my colleague Gregory Steulet on the same topic. SQL FIREWALL is a new security layer integrated into Oracle Database 23c. First, we create a admin user for which we(…)