Book Image

MariaDb Essentials

Book Image

MariaDb Essentials

Overview of this book

This book will take you through all the nitty-gritty parts of MariaDB, right from the creation of your database all the way to using MariaDB’s advanced features. At the very beginning, we show you the basics, that is, how to install MariaDB. Then, we walk you through the databases and tables of MariaDB, and introduce SQL in MariaDB. You will learn about all the features that have been added in MariaDB but are absent in MySQL. Moving on, you’ll learn to import and export data, views, virtual columns, and dynamic columns in MariaDB. Then, you’ll get to grips with full-text searches and queries in MariaDb. You’ll also be familiarized with the CONNECT storage engine. At the end of the book, you’ll be introduced to the community of MariaDB.

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MariaDb Essentials
Oct, 2015 | 206 pages
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Table of Contents (15 chapters)
MariaDB Essentials
MariaDB Essentials
Credits
Credits
About the Authors
About the Authors
About the Reviewers
About the Reviewers
www.PacktPub.com
www.PacktPub.com
Preface
Preface
Free Chapter
1
Installing MariaDB
Installing MariaDB
Choosing a MariaDB version
Installing MariaDB
Starting and stopping MariaDB
Getting started with the mysql client
Configuring MariaDB
Upgrading MariaDB
Managing plugins
Summary
2
Databases and Tables
Databases and Tables
Working with databases
Working with tables
Working with columns
Storage engines
Indexing
Using comments
Working with metadata
Creating an installation script
Summary
3
Getting Started with SQL
Getting Started with SQL
Working with rows
Understanding transactions
Foreign keys
Dealing with duplicates and consistency errors
Reading rows
Joining tables
Working with operators
Working with times and dates
Using comments to annotate your database schema
Summary
4
Importing and Exporting Data
Importing and Exporting Data
The basics of importing and exporting data
Creating and importing CSV files
Creating and importing a dump file
Speeding up data import
Summary
5
Views and Virtual Columns
Views and Virtual Columns
Views
Virtual and persistent columns
Summary
6
Dynamic Columns
Dynamic Columns
The problem: storing non-homogeneous data
Dynamic columns
Summary
7
Full-Text Searches
Full-Text Searches
Defining a full-text search
Full-text searches in MySQL and MariaDB
Working with full-text indexes
Full-text queries
Mroonga
Connecting MariaDB to Sphinx
Summary
8
Using the CONNECT Storage Engine
Using the CONNECT Storage Engine
Understanding the CONNECT storage engine
Accessing CSV files
Accessing XML and HTML files
Using the XCOL table type
Using the OCCUR table type
Using the PIVOT table type
The MariaDB community
MariaDB resources
Included storage engines
Summary
Index
Index

Virtual and persistent columns

We described a view on a virtual table, meaning that its contents are the results of a query. The idea behind virtual columns is very similar: they are columns based on SQL expressions.

A virtual column overview

The terminology is a bit confusing here. In fact, all automatically calculated columns are called virtual columns in MariaDB KnowledgeBase. However, there are two types of virtual columns: VIRTUAL columns and PERSISTENT columns.

  • A VIRTUAL column is calculated on-the-fly when it is referenced in a statement—for example, when a SELECT clause extracts its value. This is the default type.

  • A PERSISTENT column is written in the table and its value can be read when needed, as happens with regular columns.

Calculating each value on-the-fly is additional work for the CPU, but saves space on the disk. Only PERSISTENT columns can be indexed or used in a foreign key.

In both cases, the calculated values cannot be directly inserted or modified. MariaDB automatically modifies...

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