PostgreSQL: The world's most advanced open source database
WEBPostgreSQL is a powerful, open source object-relational database system with over 35 years of active development that has earned it a strong reputation for reliability, feature robustness, and performance. There is a wealth of information to be found describing how to install and use PostgreSQL through the official documentation.
PostgreSQL 16.4 Documentation
WEBPostgreSQL: Documentation: 16: PostgreSQL 16.4 Documentation. September 5, 2024: PostgreSQL 17 RC1 Released! Documentation → PostgreSQL 16. Supported Versions: Current (16) / 15 / 14 / 13 / 12. Development Versions: 17 / devel.
About - PostgreSQL
WEBSep 5, 2024 · PostgreSQL is a powerful, open source object-relational database system that uses and extends the SQL language combined with many features that safely store and scale the most complicated data workloads. The origins of PostgreSQL date back to 1986 as part of the POSTGRES project at the University of …
PostgreSQL: Documentation: 16: psql
WEBBoth the system-wide startup file and the user's personal startup file can be made psql -version-specific by appending a dash and the PostgreSQL major or minor release identifier to the file name, for example ~/.psqlrc-16 or ~/.psqlrc-16.4.
9.4. String Functions and Operators - PostgreSQL
WEB9.4.1. format. This section describes functions and operators for examining and manipulating string values. Strings in this context include values of the types character, character varying, and text. Except where noted, these functions and operators are declared to accept and return type text. They will interchangeably accept character varying ...
PostgreSQL: Documentation: 16: 8.1. Numeric Types
WEBThe type numeric can store numbers with a very large number of digits. It is especially recommended for storing monetary amounts and other quantities where exactness is required. Calculations with numeric values yield exact results where possible, e.g., addition, subtraction, multiplication. However, calculations on numeric values are very slow compared to the integer types, or to the floating ...
PostgreSQL: Documentation: 16: 25.1. Routine Vacuuming
WEBThe PostgreSQL query planner relies on statistical information about the contents of tables in order to generate good plans for queries. These statistics are gathered by the ANALYZE command, which can be invoked by itself or as an optional step in VACUUM.It is important to have reasonably accurate statistics, otherwise poor choices of plans might degrade database performance.
PostgreSQL: Documentation: 16: 1.1. Installation
WEBPostgreSQL 16.4, 15.8, 14.13, 13.16, 12.20, and 17 Beta 3 Released! 1.1. Installation. Chapter 1. Getting Started. 1.1. Installation #. Before you can use PostgreSQL you need to install it, of course. It is possible that PostgreSQL is already installed at your site, either because it was included in your operating system distribution or because ...
PostgreSQL: Documentation: 16: MERGE
WEBDescription. MERGE performs actions that modify rows in the target table identified as target_table_name, using the data_source.MERGE provides a single SQL statement that can conditionally INSERT, UPDATE or DELETE rows, a task that would otherwise require multiple procedural language statements.. First, the MERGE command performs a join from data_source to the target table producing zero or ...
PostgreSQL: Documentation: 16: 3.3. Foreign Keys
WEBAdvanced Features. 3.3. Foreign Keys #. Recall the weather and cities tables from Chapter 2. Consider the following problem: You want to make sure that no one can insert rows in the weather table that do not have a matching entry in the cities table. This is called maintaining the referential integrity of your data.