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# 9.19. Range Functions and Operators

See Section 8.17 for an overview of range types.

Table 9-45 shows the operators available for range types.

Table 9-45. Range Operators

Operator Description Example Result
= equal int4range(1,5) = '[1,4]'::int4range t
<> not equal numrange(1.1,2.2) <> numrange(1.1,2.3) t
< less than int4range(1,10) < int4range(2,3) t
> greater than int4range(1,10) > int4range(1,5) t
<= less than or equal numrange(1.1,2.2) <= numrange(1.1,2.2) t
>= greater than or equal numrange(1.1,2.2) >= numrange(1.1,2.0) t
@> contains range int4range(2,4) @> int4range(2,3) t
@> contains element '[2011-01-01,2011-03-01)'::tsrange @> '2011-01-10'::timestamp t
<@ range is contained by int4range(2,4) <@ int4range(1,7) t
<@ element is contained by 42 <@ int4range(1,7) f
&& overlap (have points in common) int8range(3,7) && int8range(4,12) t
<< strictly left of int8range(1,10) << int8range(100,110) t
>> strictly right of int8range(50,60) >> int8range(20,30) t
&< does not extend to the right of int8range(1,20) &< int8range(18,20) t
&> does not extend to the left of int8range(7,20) &> int8range(5,10) t
-|- is adjacent to numrange(1.1,2.2) -|- numrange(2.2,3.3) t
+ union numrange(5,15) + numrange(10,20) [5,20)
* intersection int8range(5,15) * int8range(10,20) [10,15)
- difference int8range(5,15) - int8range(10,20) [5,10)

The simple comparison operators <, >, <=, and >= compare the lower bounds first, and only if those are equal, compare the upper bounds. These comparisons are not usually very useful for ranges, but are provided to allow B-tree indexes to be constructed on ranges.

The left-of/right-of/adjacent operators always return false when an empty range is involved; that is, an empty range is not considered to be either before or after any other range.

The union and difference operators will fail if the resulting range would need to contain two disjoint sub-ranges, as such a range cannot be represented.

Table 9-46 shows the functions available for use with range types.

Table 9-46. Range Functions

Function Return Type Description Example Result
`lower`(anyrange) range's element type lower bound of range lower(numrange(1.1,2.2)) 1.1
`upper`(anyrange) range's element type upper bound of range upper(numrange(1.1,2.2)) 2.2
`isempty`(anyrange) boolean is the range empty? isempty(numrange(1.1,2.2)) false
`lower_inc`(anyrange) boolean is the lower bound inclusive? lower_inc(numrange(1.1,2.2)) true
`upper_inc`(anyrange) boolean is the upper bound inclusive? upper_inc(numrange(1.1,2.2)) false
`lower_inf`(anyrange) boolean is the lower bound infinite? lower_inf('(,)'::daterange) true
`upper_inf`(anyrange) boolean is the upper bound infinite? upper_inf('(,)'::daterange) true

The `lower` and `upper` functions return null if the range is empty or the requested bound is infinite. The `lower_inc`, `upper_inc`, `lower_inf`, and `upper_inf` functions all return false for an empty range.