Book Image

Mastering PostgreSQL 10

Book Image

Mastering PostgreSQL 10

Overview of this book

PostgreSQL is an open source database used for handling large datasets (big data) and as a JSON document database. This book highlights the newly introduced features in PostgreSQL 10, and shows you how you can build better PostgreSQL applications, and administer your PostgreSQL database more efficiently. We begin by explaining advanced database design concepts in PostgreSQL 10, along with indexing and query optimization. You will also see how to work with event triggers and perform concurrent transactions and table partitioning, along with exploring SQL and server tuning. We will walk you through implementing advanced administrative tasks such as server maintenance and monitoring, replication, recovery, high availability, and much more. You will understand common and not-so-common troubleshooting problems and how you can overcome them. By the end of this book, you will have an expert-level command of advanced database functionalities and will be able to implement advanced administrative tasks with PostgreSQL 10.
Table of Contents (15 chapters)

Understanding noteworthy error scenarios

After those basic guidelines to hunt down the most common issues, the upcoming sections will discuss some of the most common error scenarios happening in the PostgreSQL world.

Facing clog corruption

PostgreSQL has a thing called the commit log (now called pg_xact; it is formally known as pg_clog). It tracks the state of every transaction on the system and helps PostgreSQL determine whether a row can be seen or not. In general, a transaction can be in four states:

#define TRANSACTION_STATUS_IN_PROGRESS    0x00
#define TRANSACTION_STATUS_COMMITTED 0x01
#define TRANSACTION_STATUS_ABORTED 0x02
#define TRANSACTION_STATUS_SUB_COMMITTED 0x03

The clog has a separate directory in the...