Database Administration & Monitoring

From Oracle Standard Auditing to Oracle Unified Auditing

In this post, I will not show you all advantages related to Oracle Unified Auditing. For that, read the oracle documentation. You can also read the blogs written by my colleagues : Oracle 12c Unified Auditing Feature in(…)

Exadata X9M release

I would like to share some personal thoughts. September 28th 2021, Oracle released the eleventh Exadata data machine called "X9M-2" (2 CPU sockets), X9M-8 (8 sockets) and ZDLRA X9M. Exadata is a computing platform to run Oracle RDBMS, zero data(…)

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(…)

Magic Upgrade to 21c with Replay Upgrade Feature

Last week I did some upgrade tests from 19c to 21c. The plan was to copy a 19c PDB to a CDB 21c using Online Clone and then upgrade it to 21c. I have done this many times for 19c(…)

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(…)

After startup database with srvctl, sqlplus as sysdba results in ORA-12547: TNS:lost contact

A few days ago a customer called me, that he have a strange issue with a new created database in a oracle restart configuration with 19c. Problem The customer has patches his 19c Databases with the newest RU and(…)

MongoDB Monitoring using Nagios

The question comes frequently: How can I monitor my MongoDB cluster (ReplicaSet or Sharded) in a production environment? To answer this question we need first to get an overview of all potential monitoring solutions, and then compare them one by(…)