This book is for system administrators, database administrators, architects, developers, and anyone with an interest in planning for or running live production databases. This book is most suited to those who have some technical experience.

Chapter 1, First Steps, covers topics such as an introduction to PostgreSQL 10, downloading and installing PostgreSQL 10, connecting to a PostgreSQL server, enabling server access to network/remote users, using graphical administration tools, using psql query and scripting tools, changing your password securely, avoiding hardcoding your password, using a connection service file, and troubleshooting a failed connection.

Chapter 2, Exploring the Database, helps you identify the version of the database server you are using and also the server uptime. It helps you locate the database server files, database server message log, and database's system identifier. It lets you list a database on the database server, contains recipes that let you know the number of tables in your database, how much disk space is used by the database and tables, which are the biggest tables, how many rows a table has, how to estimate rows in a table, and how to understand object dependencies.

Chapter 3, Configuration, covers topics such as reading the fine manual (RTFM), planning a new database, changing parameters in your programs, the current configuration settings, parameters that are at non-default settings, updating the parameter file, setting parameters for particular groups of users, basic server configuration checklist, adding an external module into the PostgreSQL server, and running the server in power saving mode.

Chapter 4, Server Control, provides information about starting the database server manually, stopping the server quickly and safely, stopping the server in an emergency, reloading the server configuration files, restarting the server quickly, preventing new connections, restricting users to just one session each, and pushing users off the system. It contains recipes that help you decide on a design for multi-tenancy, how to use multiple schemas, giving users their own private database, running multiple database servers on one system, and setting up a connection pool.

Chapter 5, Tables and Data, guides you through the process of choosing good names for database objects, handling objects with quoted names, enforcing same name, same definition for columns, identifying and removing duplicate rows, preventing duplicate rows, finding a unique key for a set of data, generating test data, randomly sampling data, loading data from a spreadsheet, and loading data from flat files.

Chapter 6, Security, provides recipes on revoking user access to a table, granting user access to a table, creating a new user, temporarily preventing a user from connecting, removing a user without dropping their data, checking whether all users have a secure password, giving limited super user powers to specific users, auditing DDL changes, auditing data changes, integrating with LDAP, connecting using SSL, and encrypting sensitive data.

Chapter 7, Database Administration, provides recipes on useful topics such as writing a script wherein either all succeed or all fail, writing a psql script that exits on the first error, performing actions on many tables, adding/removing columns on tables, changing the data type of a column, adding/removing schemas, moving objects between schemas, adding/removing tablespaces, moving objects between tablespaces, accessing objects in other PostgreSQL databases, and making views updateable.

Chapter 8, Monitoring and Diagnosis, provides recipes that answer questions such as is the user connected?, what are they running?, are they active or blocked?, who is blocking them?, is anybody using a specific table?, when did anybody last use it?, how much disk space is used by temporary data?, and why are my queries slowing down? It also helps you in investigating and reporting a bug, producing a daily summary report of logfile errors, killing a specific session, and resolving an in-doubt prepared transaction.

Chapter 9, Regular Maintenance, provides useful recipes on controlling automatic database maintenance, avoiding auto freezing and page corruptions, avoiding transaction wraparound, removing old prepared transactions, actions for heavy users of temporary tables, identifying and fixing bloated tables and indexes, maintaining indexes, finding unused indexes, carefully removing unwanted indexes, and planning maintenance.

Chapter 10, Performance and Concurrency, covers topics such as finding slow SQL statements, collecting regular statistics from pg_stat* views, finding what makes SQL slow, reducing the number of rows returned, simplifying complex SQL, speeding up queries without rewriting them, why is my query not using an index?, how do I force a query to use an index?, using optimistic locking, and reporting performance problems. And of course, the new parallel query features.

Chapter 11, Backup and Recovery, insists that backups are essential, though they also devote only a very small amount of time to thinking about the topic. So, this chapter provides useful information about backup and recovery of your PostgreSQL database through recipes on understanding and controlling crash recovery, planning backups, hot logical backup of one database, hot logical backup of all databases, hot logical backup of all tables in a tablespace, backup of database object definitions, standalone hot physical database backup, hot physical backup and continuous archiving. It also includes topics such as recovery of all databases, recovery to a point in time, recovery of a dropped/damaged table, recovery of a dropped/damaged database, recovery of a dropped/damaged tablespace, improving performance of backup/recovery, and incremental/differential backup and restore. 

Chapter 12, Replication and Upgrades, explains that replication isn't magic, though it can be pretty cool. It's even cooler when it works, and that's what this chapter is all about. This chapter covers replication concepts, replication best practices, setting up file-based log shipping replication, setting up streaming log replication, managing log shipping replication, managing Hot Standby, synchronous replication, upgrading to a new minor release, in-place major upgrades, major upgrades online, plus logical replication and Postgres-BDR.

In order for this book to be useful, you need at least access to a PostgreSQL client that is allowed to execute queries on a server. Ideally, you'll also be the server administrator. Full client and server packages for PostgreSQL are available for most popular operating systems at http://www.postgresql.org/download/. All the examples here are executed at a Command Prompt, usually running the psql program. This makes them applicable to most platforms. It's straightforward to do many of these operations instead using a GUI tool for PostgreSQL, such as pgAdmin or OmniDB.

CREATE USER repuser
       SUPERUSER
       LOGIN
       CONNECTION LIMIT 1
       ENCRYPTED PASSWORD 'changeme';

SELECT *FROM mytable
 WHERE  (col1, col2, … ,colN) IN
 (SELECT col1, col2, … ,colN
  FROM mytable
  GROUP BY col1, col2, … ,colN
HAVING count(*) > 1);

$ postgres --single -D /full/path/to/datadir postgres

In this book, you will find several headings that appear frequently (Getting ready, How to do it..., How it works..., There's more..., and See also).

To give clear instructions on how to complete a recipe, use these sections as follows:

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