VSCode: How to change the font size

Visual Studio Code is a lightweight but powerful source code editor which runs on your desktop and is available for Windows, macOS and Linux. It’s developed by Microsoft. Here a guide how to change the Editor’s font and the font of the hole application (tabs, explorer, etc). This article describes how to change the VSCode’s fonts. How to open setting There 2 way of opening VSCode’s setting: Over main menu or hot keys: go to File -> Preferences -> Setting (or click on Ctrl + Alt + S) Over setting. Continue reading

Principles of Object Oriented Design

Intro Here is a list of main principles of Object Oriented Design (OOD) with short description of them. I’ll provide detailed descriptions for some of the principles in later posts. OOD principles can be divided into two groups. The first group well known and named SOLID (has 5 principles) and describes class design. The second group (6 principles) is related to the packaging of the application. Principles from these group describe how package and component design helps us to organize large application into packages or components. Continue reading

Partitioning in Relational databases

Introduction Partitioning is a process of dividing a table into multiple smaller pieces, where each piece of such a database object is called a partition. This tutorial describes what is Partitioning and provided an example of Range partitioning in PostgreSQL database. Benefits of partitioning Query performance could be increased when: most of the heavily accessed rows of the table are in a single partition or a small number of partitions. queries or updates access a large percentage of a single partition because of sequential scan of that partition instead of using an index and random access reads scattered across the whole table Seldom-used data can be migrated to cheaper and slower storage media Performing maintenance operations on one or more partitions can be made more quickly. Continue reading

How to run Spring Boot and MongoDB in Docker container

Introduction This tutorial describes how to run Spring Boot application and Mongo DB in Docker containers. For a demo purposes we’ll use the following project: spring-mongo-demo. All sources can be found on Github. Our goal is to run our Spring Boot application and MongoDB in its own containers. Some words about Demo project Demo project (spring-boot-demo) is very simple and does the following: it saves the users into Mongo DB. A new added user is displayed in the Users table on the bottom of the page: Requirements We need: Continue reading

How to install Docker on Ubuntu 16.04

Introduction Docker is software containerization platform which makes it easier to create, deploy, and run applications by using containers. It’s the most popular containerization platform in our days. More details about Docker could be found on Docker official web site or Wikipedia. This tutorial describes only how to install Docker on Ubuntu 16.04. Installation process on other distribution looks very similar but can have some differences. How to use Docker will be described into future tutorials. Continue reading

SQL Query explain plan and Optimization

Query optimization is determination by relational database the most efficient way to execute a given query by considering the possible query plans. Mostly query optimizer is used by databases for optimizing the query in the best possible way. User doesn’t work directly with query optimizer. But some queries can be optimized by exploring its execution plan. Prepare test data Before we dive into queries optimizations and explain plan, let’s prepare a table with test data. Continue reading

Indexes into Relational Databases

A database index is a data structure that improves the speed of data retrieval operations on a database table (increase database performance). But such performance has a cost of additional writes to hard drive and storage space to maintain the index data structure. In nutshell, index is a quick path to a single row into database. Indexes allow us to go directly to he required column without scanning the entire database table. Continue reading