Online Documentation for SQL Manager for PostgreSQL

Creating/editing operator


Use the Operator tab of Operator Editor to create/edit an operator and specify its definition.

 

Operator Editor - Editing operator definition

 

 

Name

Select a schema and enter the name of the operator to be defined. See below for allowable characters. Two operators in the same schema can have the same name if they operate on different data types. This is called overloading.

 

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.

 

Function

The function used to implement this operator. Select it from the list of all database functions.

 

Left operand type

The type of the left-hand argument of the operator, if any. This option would be omitted for a left-unary operator.

 

Right operand type

The type of the right-hand argument of the operator, if any. This option would be omitted for a right-unary operator.

 

Commutator

Use the drop-down list to select the commutator of this operator.

 

Negator

Use the drop-down list to select the negator of this operator.

 

Restrict function

Use the drop-down list to select the restriction selectivity estimator function for this operator.

 

Join function

Use the drop-down list to select the join selectivity estimator function for this operator.

 

CheckBox Support hash joins

Check this option to indicate that this operator can support a hash join.

 

CheckBox Support merge joins

Check this option to indicate that this operator can support a merge join.

 

Left sort operator

If this operator can support a merge join, select the operator that sorts the left-hand data type of this operator.

 

Right sort operator

If this operator can support a merge join, select the operator that sorts the right-hand data type of this operator.

 

Less than operator

If this operator can support a merge join, select the less-than operator that compares the input data types of this operator.

 

Greater than operator

If this operator can support a merge join, select the greater-than operator that compares the input data types of this operator.