Book Image

PostgreSQL 10 High Performance - Third Edition

By : Enrico Pirozzi
Book Image

PostgreSQL 10 High Performance - Third Edition

By: Enrico Pirozzi

Overview of this book

PostgreSQL database servers have a common set of problems that they encounter as their usage gets heavier and requirements get more demanding. Peek into the future of your PostgreSQL 10 database's problems today. Know the warning signs to look for and how to avoid the most common issues before they even happen. Surprisingly, most PostgreSQL database applications evolve in the same way—choose the right hardware, tune the operating system and server memory use, optimize queries against the database and CPUs with the right indexes, and monitor every layer, from hardware to queries, using tools from inside and outside PostgreSQL. Also, using monitoring insight, PostgreSQL database applications continuously rework the design and configuration. On reaching the limits of a single server, they break things up; connection pooling, caching, partitioning, replication, and parallel queries can all help handle increasing database workloads. By the end of this book, you will have all the knowledge you need to design, run, and manage your PostgreSQL solution while ensuring high performance and high availability
Table of Contents (18 chapters)

Indexing example walkthrough

Discussion of indexes and query plans can quickly reach an overwhelming level of theory. Instead, this section will lead you through running various queries, with and without useful indexes, and showing how the query execution changes.

Measuring query disk and index block statistics

The best way to really understand how indexes work to save on the number of disk reads is to show how many blocks were actually used to satisfy that query. The following view merges together the two main sources for relevant table statistics, pg_stat_user_tables and pg_statio_user_tables:

CREATE OR REPLACE VIEW table_stats AS
SELECT
 stat.relname AS relname, 
 seq_scan, seq_tup_read, idx_scan, idx_tup_fetch,
 heap_blks_read...