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    PolarDB:ST_MatchGridLevel

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    PolarDB:ST_MatchGridLevel

    Last Updated:Mar 28, 2026

    Returns the highest available grid level for a Digital Elevation Model (DEM) raster based on its resolution.

    Syntax

    smallint ST_MatchGridLevel(raster dem);

    Parameters

    ParameterDescription
    demA raster containing terrain elevation data. The coordinate system must be Geodetic Coordinate System (GCS) 2000, EPSG:4490.

    Usage notes

    • Do not use a grid level higher than the value returned by this function when performing path calculations.

    • If the input raster is not in EPSG:4490, convert it to EPSG:4490 first using ST_Transform.

    Examples

    SELECT ST_MatchGridLevel(dem);

    Output:

     21

    See also

    • ST_Transform — converts a raster to a different coordinate system