Note that the“same as”operator,
~=, represents the usual notion of equality for the
circletypes. Some of these types also have an
=compares for equal_areas_only. The other scalar comparison operators (
<=and so on) likewise compare areas for these types.
Table 9.33. Geometric Operators
BeforePostgreSQL8.2, the containment operators
<@were respectively called
@. These names are still available, but are deprecated and will eventually be removed.
Table 9.34. Geometric Functions
Table 9.35. Geometric Type Conversion Functions
It is possible to access the two component numbers of a
pointas though the point were an array with indexes 0 and 1. For example, if
SELECT p FROM tretrieves the X coordinate and
UPDATE t SET p = ...changes the Y coordinate. In the same way, a value of type
lsegcan be treated as an array of two
areafunction works for the types
areafunction only works on the
pathdata type if the points in the
pathare non-intersecting. For example, the
path'((0,0),(0,1),(2,1),(2,2),(1,2),(1,0),(0,0))'::PATHwill not work; however, the following visually identical
path'((0,0),(0,1),(1,1),(1,2),(2,2),(2,1),(1,1),(1,0),(0,0))'::PATHwill work. If the concept of an intersecting versus non-intersecting
pathis confusing, draw both of the above
paths side by side on a piece of graph paper.