ST_Generalize function for aggregating geographic grids - ApsaraDB RDS

Aggregates a geographic grid or an array of geographic grids to a lower aggregation level.

Syntax

geomgrid ST_Generalize(geomgrid gridcode, integer precision);
geomgrid[] ST_Generalize(geomgrid[] gridarray, integer precision, bool degenerated default false);

Parameters

Parameter	Description
`gridcode`	The geographic grid object.
`gridarray`	The array of geographic grids.
`precision`	The aggregation level.
`degenerated`	Specifies whether to use a degenerated grid. Default value: `false`.

Examples

Aggregate a single grid to level 5:

SELECT ST_AsText(ST_Generalize(ST_GridFromText('GZ0026206440'), 5));
 st_astext
-----------
 GZ00262

Aggregate a 3D grid array derived from a line geometry to level 8:

SELECT ST_Generalize(ST_As3DGrid(
'srid=4490;LINESTRING Z (116 39 2000,116.012 39.009 3000)'::geometry, 10), 8);
                st_generalize
---------------------------------------------
 {01024008722600000000,01024008742600000000}