ST_Segmentize-ApsaraDB RDS(RDS)-阿里云帮助中心

Returns a modified geometry or geography having no segment longer than a given distance. Short segments are left unchanged.

Syntax

geometry  ST_Segmentize(geometry  geom , float  maxSegmentLength);
geography ST_Segmentize(geography geog , float  maxSegmentLength);

Parameter	Description
`geom`	The geometry object to segmentize.
`geog`	The geography object to segmentize.
`maxSegmentLength`	The maximum segment length. For geometry, the unit follows the spatial reference of the input. For geography, the unit is meters.

Only segments longer than maxSegmentLength are split. Segments shorter than maxSegmentLength are not modified.

The 1-unit segment (2 1, 1 1) is split into two 0.5-unit subsegments, adding vertex (1.5 1).

SELECT ST_AsText(ST_Segmentize(ST_GeomFromText('LINESTRING(2 1,1 1)'),0.5));

Expected output:

         st_astext
---------------------------
 LINESTRING(2 1,1.5 1,1 1)
(1 row)