This function merges an array of pcpatch entries into a pcpatch object.

Syntax

pcpatch ST_union(pcpatch[] pcs);

Parameters

Parameter Description
pcs The pcpatch array.

Examples

-- Compare npoints(sum(patches)) with sum(npoints(patches)).
SELECT ST_NumPoints(ST_Union(pa)) FROM patches;
SELECT Sum(ST_NumPoints(pa)) FROM patches;

100