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estimated_envelope

1. ESTIMATED_ENVELOPE Function​

The ESTIMATED_ENVELOPE function in H2 database is used to estimate the minimum bounding rectangle (envelope) of a spatial object.

2. Syntax​

The syntax for the ESTIMATED_ENVELOPE function in H2 database is as follows:

ESTIMATED_ENVELOPE(geometry)

Arguments​

  • geometry: The spatial object for which the estimated envelope needs to be calculated. It should be a valid geometry object.

Return​

  • The ESTIMATED_ENVELOPE function returns the estimated minimum bounding rectangle (envelope) of the given spatial object.

3. Notes​

  • The ESTIMATED_ENVELOPE function in H2 database is an estimation and may not provide a precise result.
  • The input spatial object should be a valid geometry object. Invalid or null geometries may result in unexpected behavior or errors.
  • This function is specific to spatial operations in H2 database and may not be available in other databases.

4. Examples​

Here are a few examples demonstrating the usage of the ESTIMATED_ENVELOPE function in H2 database:

Example 1 - Calculating the estimated envelope of a point:​

SELECT ESTIMATED_ENVELOPE('POINT(10 20)') AS envelope;

Output:

envelope
----------
POLYGON((10 20,10 20,10 20,10 20))

Example 2 - Calculating the estimated envelope of a polygon:​

SELECT ESTIMATED_ENVELOPE('POLYGON((0 0, 0 10, 10 10, 10 0, 0 0))') AS envelope;

Output:

envelope
----------
POLYGON((0 0,0 10,10 10,10 0,0 0))
  • ENVELOPE - Calculate the exact minimum bounding rectangle of a spatial object.
  • ST_X - Get the X-coordinate of a point.
  • ST_Y - Get the Y-coordinate of a point.