PostgreSQL is an open source, object-oriented relational database system. It supports many advanced features and complies with the ANSI-SQL standard. It has won industry recognition and user appreciation. The PostgreSQL slogan The world's most advanced open source database reflects the sophistication of the PostgreSQL features. It is a result of many years of research and collaboration between academia and industry. Start-up companies often favor PostgreSQL due to licensing costs and it can aid profitable business models. PostgreSQL is also favored by many developers because of its capabilities and advantages.

PostgreSQL can be used for OLTP and OLAP applications. It is ACID compliant; thus, it can be used out of the box for OLTP applications. For OLAP applications, PostgreSQL supports the Windows functions, FDW, and table inheritance. Also, there are many external extensions. Several proprietary DBMSs are based on PostgreSQL. In addition to that, there are several open source forks that add new features and technologies to PostgreSQL such as MPP and MapReduce.

PostgreSQL has a very organized active community including users, developers, companies, and associations. The community contributes to PostgreSQL on a daily basis; many companies have contributed to PostgreSQL by publishing best practices or articles, submitting feature requests to the development group, submitting new features, and developing new tools and software. 

The first interaction with PostgreSQL is quick and easy, and one requires a few minutes to install it. PostgreSQL is shipped with many client tools to help user interactions. PostgreSQL is user-friendly the psql meta command h, ?, iming</kbd>, pset, auto-completion, and so on make it easy for the developer to complete his tasks quickly.

In the next chapter, the PostgreSQL building components will be introduced. Also, the user will be able to create his first database and use some DDL statements such as CREATE TABLE and CREATE VIEW. The next chapter will provide some advice regarding coding and coding style for SQL and will provide an overview of high-level component interactions.