8.12 Summary

PostgreSQL is a highly developed database that is mainly based on ANSI SQL. Up to now a major part of the ANSI specification has been implemented in the server and the developers are working hard to continue this project.

Constraints are used to define certain attributes and restrictions as well as to guarantee data integrity. PostgreSQL provides a pool of constraints used to work with data integrity.

To speed up your database, you can tune PostgreSQL, making heavy use of optimizer settings.

Queries can be combined with each other in order to build more complex operations. For this purpose, ANSI SQL defines many keywords.