diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 82081e514fa..a5d81b6fddc 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -1,5 +1,5 @@ @@ -5971,6 +5971,22 @@ SELECT TIMESTAMP 'now'; as an array of two point values. + + The area function works for the types + box, circle, and path. + The area function only works on the + path data type if the points in the + path are non-intersecting. For example, the + path + '((0,0),(0,1),(2,1),(2,2),(1,2),(1,0),(0,0))'::PATH + won't 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))'::PATH + will work. If the concept of an intersecting versus + non-intersecting path is confusing, draw both of the + above paths side by side on a piece of graph paper. + +