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ST_Envelope

Returns the minimum bounding box (envelope) of a geometry.

Syntax​

ST_Envelope(geometry)

Parameters​

ParameterTypeDescription
geometryGeometryInput geometry

Returns​

TypeDescription
Binary (WKB)Bounding box as WKB polygon with geoarrow.wkb metadata

Examples​

Envelope of Polygon​

SELECT ST_Envelope(ST_GeomFromText('POLYGON((0 0, 3 0, 3 2, 1 4, 0 2, 0 0))'));
-- Returns: POLYGON((0 0, 3 0, 3 4, 0 4, 0 0))

Envelope of LineString​

SELECT ST_Envelope(ST_GeomFromText('LINESTRING(0 0, 1 1, 2 0)'));
-- Returns: POLYGON((0 0, 2 0, 2 1, 0 1, 0 0))

Calculate Extent of Features​

SELECT category, ST_Envelope(ST_Union(geom)) as extent
FROM features
GROUP BY category;

Pre-filter with Envelope​

SELECT * FROM detailed_features
WHERE ST_Intersects(ST_Envelope(geom), search_box);

Notes​

  • Returns the axis-aligned minimum bounding rectangle
  • For Points, returns a polygon with zero area
  • For horizontal/vertical lines, returns a degenerate polygon
  • Useful for spatial indexing and quick intersection tests
  • Envelope intersection is faster than full geometry intersection

See Also​