# CREATE_OPERATOR - define a new operator - man(7) - [phpMan]

_CREATE_ [_OPERATOR_(7)](https://www.chedong.com/phpMan.php/man/OPERATOR/7/markdown)                 PostgreSQL 16.14 Documentation                 _CREATE_ [_OPERATOR_(7)](https://www.chedong.com/phpMan.php/man/OPERATOR/7/markdown)

## NAME
       CREATE_OPERATOR - define a new operator

## SYNOPSIS
       CREATE OPERATOR _name_ (
           {FUNCTION|PROCEDURE} = _function_name_
           [, LEFTARG = _left_type_ ] [, RIGHTARG = _right_type_ ]
           [, COMMUTATOR = _com_op_ ] [, NEGATOR = _neg_op_ ]
           [, RESTRICT = _res_proc_ ] [, JOIN = _join_proc_ ]
           [, HASHES ] [, MERGES ]
       )

## DESCRIPTION
       **CREATE OPERATOR **defines a new operator, _name_. The user who defines an operator becomes its
       owner. If a schema name is given then the operator is created in the specified schema.
       Otherwise it is created in the current schema.

       The operator name is a sequence of up to NAMEDATALEN-1 (63 by default) characters from the
       following list:

           + - * / < > = ~ ! @ # % ^ & | ` ?

       There are a few restrictions on your choice of name:

       •   -- and /* cannot appear anywhere in an operator name, since they will be taken as the
           start of a comment.

       •   A multicharacter operator name cannot end in + or -, unless the name also contains at
           least one of these characters:

               ~ ! @ # % ^ & | ` ?

           For example, @- is an allowed operator name, but *- is not. This restriction allows
           PostgreSQL to parse SQL-compliant commands without requiring spaces between tokens.

       •   The symbol => is reserved by the SQL grammar, so it cannot be used as an operator name.

       The operator != is mapped to <> on input, so these two names are always equivalent.

       For binary operators, both LEFTARG and RIGHTARG must be defined. For prefix operators only
       RIGHTARG should be defined. The _function_name_ function must have been previously defined
       using **CREATE FUNCTION **and must be defined to accept the correct number of arguments (either
       one or two) of the indicated types.

       In the syntax of CREATE OPERATOR, the keywords FUNCTION and PROCEDURE are equivalent, but the
       referenced function must in any case be a function, not a procedure. The use of the keyword
       PROCEDURE here is historical and deprecated.

       The other clauses specify optional operator optimization clauses. Their meaning is detailed
       in Section 38.15.

       To be able to create an operator, you must have USAGE privilege on the argument types and the
       return type, as well as EXECUTE privilege on the underlying function. If a commutator or
       negator operator is specified, you must own these operators.

## PARAMETERS
       _name_
           The name of the operator to be defined. See above for allowable characters. The name can
           be schema-qualified, for example CREATE OPERATOR myschema.+ (...). If not, then the
           operator is created in the current schema. Two operators in the same schema can have the
           same name if they operate on different data types. This is called overloading.

       _function_name_
           The function used to implement this operator.

       _left_type_
           The data type of the operator's left operand, if any. This option would be omitted for a
           prefix operator.

       _right_type_
           The data type of the operator's right operand.

       _com_op_
           The commutator of this operator.

       _neg_op_
           The negator of this operator.

       _res_proc_
           The restriction selectivity estimator function for this operator.

       _join_proc_
           The join selectivity estimator function for this operator.

       HASHES
           Indicates this operator can support a hash join.

       MERGES
           Indicates this operator can support a merge join.

       To give a schema-qualified operator name in _com_op_ or the other optional arguments, use the
       OPERATOR() syntax, for example:

           COMMUTATOR = OPERATOR(myschema.===) ,

## NOTES
       Refer to Section 38.14 for further information.

       It is not possible to specify an operator's lexical precedence in **CREATE OPERATOR**, because
       the parser's precedence behavior is hard-wired. See Section 4.1.6 for precedence details.

       The obsolete options SORT1, SORT2, LTCMP, and GTCMP were formerly used to specify the names
       of sort operators associated with a merge-joinable operator. This is no longer necessary,
       since information about associated operators is found by looking at B-tree operator families
       instead. If one of these options is given, it is ignored except for implicitly setting MERGES
       true.

       Use **DROP OPERATOR **to delete user-defined operators from a database. Use **ALTER OPERATOR **to
       modify operators in a database.

## EXAMPLES
       The following command defines a new operator, area-equality, for the data type box:

           CREATE OPERATOR === (
               LEFTARG = box,
               RIGHTARG = box,
               FUNCTION = area_equal_function,
               COMMUTATOR = ===,
               NEGATOR = !==,
               RESTRICT = area_restriction_function,
               JOIN = area_join_function,
               HASHES, MERGES
           );

## COMPATIBILITY
       **CREATE OPERATOR **is a PostgreSQL extension. There are no provisions for user-defined operators
       in the SQL standard.

## SEE ALSO
       ALTER OPERATOR ([**ALTER_OPERATOR**(7)](https://www.chedong.com/phpMan.php/man/ALTEROPERATOR/7/markdown)), CREATE OPERATOR CLASS ([**CREATE_OPERATOR_CLASS**(7)](https://www.chedong.com/phpMan.php/man/CREATEOPERATORCLASS/7/markdown)), DROP
       OPERATOR ([**DROP_OPERATOR**(7)](https://www.chedong.com/phpMan.php/man/DROPOPERATOR/7/markdown))

PostgreSQL 16.14                                2026                              _CREATE_ [_OPERATOR_(7)](https://www.chedong.com/phpMan.php/man/OPERATOR/7/markdown)