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)

Statistics

The least-appreciated part of query optimization is the collection of database statistics. Often, when questions such as "why isn't the optimizer using my index?" are asked, it is poor statistics that are really to blame.

Statistics are collected for each column in every table in a database when ANALYZE is executed against the table. If you're running with autovacuum turned on, it will usually run often enough to keep accurate statistics available. Unlike a complete vacuum cleanup, which can take quite some time on large tables, analyzing a table should take only a few seconds at any table size. It doesn't take anything other than a read lock while running, either.

Viewing and estimating with statistics

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