About

PostgreSQL (often "Postgres", never "Postgre"), is an object-relational database management system (ORDBMS) available for all major operating systems. It is free and open-source software released under the PostgreSQL License, an MIT-style license. PostgreSQL is developed by the PostgreSQL Global Development Group, consisting of volunteers employed by companies such as Red Hat and EnterpriseDB.

PostgreSQL is pronounced as "post-grez-q-l". Postgres is pronounced as "post-grez".

Numerous forks of Postgres exist for specialized tasks, such as Greenplum Database, Amazon Redshift, ParAccel, Postgres-XC, Postgres-XL, PPAS, etc. Their features and syntax differ from stock PostgreSQL. Declare what you are using and add a tag.

PostgreSQL Features

• Implements most of the major features of SQL:2016
• ACID-compliant
• Fully transactional (including all DDL statements)
• Extensible data types, operators, indexing, functions, aggregates, procedural languages
• A large number of extensions, both bundled and supplied by third parties
• Supported operating systems include: Linux, FreeBSD, Solaris, MS Windows, Mac OS X
• Detailed, comprehensive and precise documentation

How to ask good questions

For performance questions consider instructions for postgresql-performance.

For questions targeting a specific version add a version tag: postgresql-9.6, postgresql-13 etc.

Questions concerning the administration or advanced features are best directed to dba.StackExchange.com.

The Guide to Reporting Problems on the PostgreSQL wiki is helpful reading.

• Show at least your major PostgreSQL version from SELECT version().

• Include the full text of relevant error messages, SQL queries, etc.

• Where appropriate, supply a test case with CREATE TABLE and INSERT statements with sample data and expected results. A fiddle site like dbfiddle.uk or sqlfiddle.com is typically useful.

• If you've asked previous, related questions, add a link.

• If you re-post a mailing list question, link to the page in the mailing list archives. And vice versa.

• Know about PostgreSQL current settings/backend config with:

   SELECT name, current_setting(name), source FROM pg_settings
   WHERE  source NOT IN ('default', 'override');
  

Resources

• The current manual
• PostgreSQL GUI Tools
• PostgreSQL Wiki
• PostgreSQL on Wikipedia
• Mailing list archives
• PostgreSQL IRC channels
• Books

Useful links

• PostgreSQL Tutorials
• PostgreSQL Online Tutorial
• PostgreSQL SQL Tricks
• PostgreSQL on Reddit
• PostgreSQL documentation compliment