05. 06. 2021.

Missing columns in PrestoSQL

One of the first issues when starting to use PrestoSQL distributed query engine is related to missing columns of certain data types, especially numeric and all variants of date. This issue is usually because of missing precision at the data source, which is not only one of the most common, but also one of the […]

16. 02. 2021.

Postgres monitoring with Percona PMM

For those who are coming from Oracle world, the best alternative database is probably Postgres, because of many similarities between those two Db engines (data types, tablespace concept etc.).   However, one of the first thing you want to do is to grab a full control over what is going on in your database. If […]

21. 01. 2021.

Kafka & TCP Retrans Error rate

Recently I had an interesting case where in the data pipeline I’ve found duplicate messages in the Kafka topics. Duplicate records in Kafka topics might appear for many different reasons, but most of them you can find only those related to the Kafka settings (especially those related to the Kafka settings). In this article you […]

06. 12. 2020.

Bashtop – future of the terminal Linux monitoring

Although the idea of the original top utility is follewed in many similar utilities for terminal based Linux monitoring, till now I’ve been using Htop, atop (which can monitor GPU on top of CPU/Mem/Net/Disk) and Nmon to do a job (later one, called „Topas on steroids” is ported from AIX to Linux). Quite recently I’ve […]

06. 10. 2020.

Perfect case for NoSQL database

On many sites where I’ve been involved in troubleshooting and performance tuning, I can find usage of wrong technology for a wrong use case. Usually client technology experts are keen with some new features of some technology and want to solve all kind of problems by using it. In practice, new features are added to […]

24. 09. 2020.

How to setup Adobe Flash Support in Browser for Linux

Some vendors still relies on Adobe Flash for rich web contents. One such example is Oracle, where you can find that all tuning reports are generated by using Flash. Even Oracle Enterprise Manager Grid, main Oracle monitoring tool still uses Adobe Flash to generate its content. If you are on Windows, you can use Internet […]

10. 05. 2020.

Customer experience on Oracle Db – One metric to rule them all

Over the years I’ve found that almost every enterprise monitoring software I’ve been working with so far (and there are a few dozen of them), put extensive load on targets under the monitoring. While one monitoring tool brings extensive hard parsing on its targets, another one calculates free space for each tablespace in a very […]

20. 01. 2020.

Configuring environment for debugging PL/SQL Stored procedures

Main objective of this post is to list some of the typical issues I’ve found when debugging PL/SQL stored procedures, functions and packages. There are many ways of how you can debug server side code, and here is the list of the most common ways I’ve found in practice: dbms_debug_jdwp dbms_debug dbms_output database tables used […]

07. 01. 2020.

Oracle database links – performance impact

In this post I’m going to explain the most important drawbacks when using db links technology for purposes for which it is not design for. To be more precise, the case in which db links are used to massively exchange data between many separate databases will be explained. In the previous post you can find […]

21. 10. 2019.

Performing stress test against Oracle database that is running in a Cloud

Today majority of enterprises are moving or at least considering moving some load into the Cloud. What you need to be aware in such case, system requirements for a Cloud load are quite different when comparing with on-premises, mainly due to many new moving parts that are not present within classical environment such as sharing […]