PostgreSQL Reference Manual - Volume 1 - SQL Language Reference by The PostgreSQL Global Development Group Paperback (6"x9"), 716 pages ISBN 0954612027 RRP £32.00 ($49.95) Sales of this book support the PostgreSQL project! Get a printed copy>>>

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7 Functions and Operators

PostgreSQL provides a large number of functions and operators for the built-in data types. Users can also define their own functions and operators, as described in Volume 2: Server Programming. The psql commands \df and \do can be used to show the list of all actually available functions and operators, respectively.

If you are concerned about portability then take note that most of the functions and operators described in this chapter, with the exception of the most trivial arithmetic and comparison operators and some explicitly marked functions, are not specified by the SQL standard. Some of the extended functionality is present in other SQL database management systems, and in many cases this functionality is compatible and consistent between the various implementations. This chapter is also not exhaustive; additional functions appear in relevant sections of the manual.