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 […]

18. 03. 2020.

String aggregation – part II

Last time I’ve suggested two ways of how to perform string concatenation. Unfortunately, both approaches have serious drawbacks that you might experience. In this post I’ll explain one approach which is not Oracle version dependent, which corrects both shortcomings of previously described methods: size of concatenated string speed of data processing Part I you can […]

17. 03. 2020.

String aggregation – part I

Very often you’ll find delimited text to be more suitable format option instead of splitting text in many rows. Typical use cases for having delimited text includes preparation of data for further analysis, reporting, importing data into the spreadsheet etc. To demonstrate the concept, I’ll use my demo table TEST with 10 million rows. And […]

21. 02. 2020.

External C procedures – how to setup and performance boost you can expect

In this post I’ll explain what you need to do to setup external C procedure call with Oracle 18c. I’ll also show for a CPU intensive task, what performance boost you might expect. For those of you who remember how difficult it was to configure LISTENER and TNSNAMES to work with C external procedures, will […]

13. 01. 2020.

Descending Index type – performance and limitations

The main topic of this article is the DESC index type, which is often mixed-up with the Btree index type because of the great similarity they share when looking at the index creation syntax. “Raison d’etre” for having DESC index type is to avoid expensive sorting when you are sure you’ll always query and sort […]

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 […]

02. 01. 2020.

Oracle database links – locking strategy

In this post mechanism of Oracle database link technology along with locking strategy used by Oracle database will be described. Today in almost all production environments based on Oracle databases where I’ve been called to help with optimization & tuning, it is a quite common to have at least one or more db links to […]

16. 12. 2019.

Oracle RAC in the AWS Cloud – performance testing part III

This is the last part of the series called “Oracle RAC in the AWS Cloud”. In my previous article I’ve promised to put a Oracle RAC cluster under the crazy load. It was time to fulfill my promise. My previous articles you can find on the following two links: https://www.josip-pojatina.com/en/oracle-rac-in-the-aws-cloud-performance-testing-part-i/ & https://www.josip-pojatina.com/en/oracle-rac-in-the-aws-cloud-performance-testing-part-ii/ Let’s go straight […]