19. 02. 2019.

Bulk collect and memory limits

We all know that for bulk collect PL/SQL operation it’s important to keep the memory consumption under control. For that reason all bulk collect operations should be combined with a LIMIT clause like in the following code fragment: Setting the limit to process only 10K records in bulk is does not impress me in a […]

11. 02. 2019.

Performance comparison: Python & cx_Oracle versus SQL*Plus & SQL*Net

In this article I want to check the truth about the slowness of Python language when it comes to retrieving data directly from Oracle database. Second goal is to show graphically impact of changing the array size on performance, which is not possible and convenient to do with SQL*Plus.   Python is widely used as […]

10. 02. 2019.

Impact of the parameter arraysize on performance

Main goal of this article is to explain impact of the parameter arraysize on database performance. First it’s important to define what array size is. The array size is the number of rows fetched by the server. I’m using Oracle’s SH demo schema, and it’s SALES table which has almost 1 million rows. In the […]

06. 02. 2019.

Introduction to Constraint Programming

Constraint programming is set of algorithms that can help you to identify feasible solutions out of a very large set of possible values that satisfy all given constraints. It relies on logic-based methods such as domain reduction and constraint propagation to accelerate the search by eliminating all the impossible solutions in an efficient way. Main […]

05. 02. 2019.

OpenJDK Mission Control – how to install it properly

If there is one tool that have almost all what is needed for monitoring, troubleshooting and tuning Java apps, that will be OpenJDK Mission Control.   There are several reasons why JMC will be hot topic in Java events from now on: More than 95% of all issues related to JVM, application servers, deployed apps […]

03. 02. 2019.

Starting with Oracle Unit Testing Framework – Part 1

For developers that are using Scrum methodology, it is not important to stress importance of unit tests when developing a new piece of code. Unit tests are important for many reasons like: can find problems in just developed/changed code at the earliest stage (before testing team) are the smallest testable part of application cover just […]

29. 01. 2019.

Putty for Linux copy/paste issue and solution

Putty is probably the most common tool to access Unix/Linux environments on Windows platform by using ssh protocol. Recently I’ve been in situation where I’ve got only Putty generated ppk file to access Unix server. Although I’ve asked if I can get open ssh generated file, that was not possible, as it was assumed that […]

28. 01. 2019.

Easy way to create Virtualbox VM’s internal network

Virtualbox is a very popular hypervisor which allows you to run guest virtual machines like Windows, Linux, BSD, Solaris etc. For various purposes you might want to combine several virtual machines into one network. In this post I’ll describe the easiest way of how to do that, which is good enough for most of the […]

25. 01. 2019.

Installing Oracle JDeveloper on Ubuntu

To complete configuration of Ubuntu machine that I’ll use later for Oracle Development, let’s install JDeveloper, Oracle’s main Java development tool. Although JDeveloper is free, it has never had any significant traction among Java developers. In Java IDE space there are several great competitors, starting with Eclipse, IntelliJ and NetBeans. With such competition it’s difficult […]

24. 01. 2019.

Installing SQL Developer on Ubuntu

Today it is not necessary to introduce SQL Developer, Oracle’s main tool to work with databases. I’ve started to use SQL Developer from the beginning (2015, project Raptor, later renamed into SQL Developer). Before that, the only Oracle tool for working with it’s flagship database was SQL*Plus (and iSQL*Plus later). For that reason, most of […]