Book Image

SQL Server on Linux

Book Image

SQL Server on Linux

Overview of this book

Microsoft's launch of SQL Server on Linux has made SQL Server a truly versatile platform across different operating systems and data-types, both on-premise and on-cloud. This book is your handy guide to setting up and implementing your SQL Server solution on the open source Linux platform. You will start by understanding how SQL Server can be installed on supported and unsupported Linux distributions. Then you will brush up your SQL Server skills by creating and querying database objects and implementing basic administration tasks to support business continuity, including security and performance optimization. This book will also take you beyond the basics and highlight some advanced topics such as in-memory OLTP and temporal tables. By the end of this book, you will be able to recognize and utilize the full potential of setting up an efficient SQL Server database solution in your Linux environment.
Table of Contents (19 chapters)
Title Page
Credits
About the Author
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface

How transaction log works


If you are Linux user with MySQL and PostgreSQL experience, you have probably noticed that SQL Server works with two types of files, .data and .log:

  • data: A container file for database objects and data itself
  • log: A container file for logging database operations, depending on recovery model

Each database has at least one data and log file. However, based on business needs, this number can be larger.

The transaction log file is the heart of Atomicity, Consistency, Integrity, and Durability (ACID). Those four magic words are the most powerful tools of every relational database. In a nutshell, it helps that, if something goes wrong during the business process, all changes are written to the database or returned to the state prior to the transaction. ACID in SQL Server is implemented through Write Ahead Log (WAL). The following figure describes that process:

Figure 7-1 WAL process in SQL Server

As you see, all changes are made first on the memory level and written to the...