Geospatial functions

Spatial functions allow for operations relating to the geohash types which provide geospatial data support. For more information on this type of data, see the geohashes documentation and the operators which help with filtering data.

rnd_geohash

rnd_geohash(bits) returns a random geohash of variable precision.

Arguments:

bits - an integer between 1 and 60 which determines the precision of the generated geohash.

Return value:

Returns a geohash

Examples:

SELECT rnd_geohash(7) g7,
      rnd_geohash(10) g10,
      rnd_geohash(30) g30,
      rnd_geohash(29) g29,
      rnd_geohash(60) g60
FROM long_sequence(5);

g7	g10	g30	g29	g60
1101100	4h	hsmmq8	01110101011001101111110111011	rjtwedd0z72p
0010011	vf	f9jc1q	10101111100101111111101101101	fzj09w97tj1h
0101011	kx	fkhked	01110110010001001000110001100	v4cs8qsnjkeh
0000001	07	qm99sm	11001010011011000010101100101	hrz9gq171nc5
0101011	6t	3r8jb5	11011101010111001010010001010	fm521tq86j2c

make_geohash

make_geohash(lon, lat, bits) returns a geohash equivalent of latitude and longitude, with precision specified in bits.

make_geohash() is intended to be used via SQL over HTTP / PostgreSQL wire protocol, for use within Java (embedded) scenario, see the Java embedded documentation for geohashes.

Arguments:

• lon - longitude coordinate as a floating point value with up to eight decimal places
• lat - latitude coordinate as a floating point value with up to eight decimal places
• bits - an integer between 1 and 60 which determines the precision of the generated geohash.

The latitude and longitude arguments may be constants, column values or the results of a function which produces them.

Return value:

Returns a geohash.

• If latitude and longitude comes from constants and is incorrect, an error is thrown
• If column values have invalid lat / long coordinates, this produces null.

Examples:

SELECT make_geohash(142.89124148, -12.90604153, 40)