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ST_HILBERT

Encodes a GEOMETRY or GEOGRAPHY object into a Hilbert curve index. The function uses the center of the geometry's bounding box as the point to encode. When bounds are provided, the point is normalized into the specified bounding box before encoding.

Syntax

ST_HILBERT(<geometry_or_geography>)
ST_HILBERT(<geometry_or_geography>, <bounds>)

Arguments

Arguments	Description
`<geometry_or_geography>`	The argument must be an expression of type GEOMETRY or GEOGRAPHY.
`<bounds>`	Optional. An array `[xmin, ymin, xmax, ymax]` used to normalize the point before encoding.

Note

Geometry: If no bounding box is provided, GEOMETRY coordinates are not normalized to a specific bounding box. Instead, the center point values are mapped to the full float32 domain, and then encoded into the Hilbert index.
Geography: If no bounding box is provided, the default bounds are [-180, -90, 180, 90].

Return Type

UInt64.

Examples

GEOMETRY examples

SELECT ST_HILBERT(TO_GEOMETRY('POINT(1 2)')) AS hilbert1, ST_HILBERT(TO_GEOMETRY('POINT(5 5)')) AS hilbert2;

╭───────────────────────────╮
│   hilbert1  │   hilbert2  │
├─────────────┼─────────────┤
│  3355443200 │  2155872256 │
╰───────────────────────────╯

SELECT ST_HILBERT(TO_GEOMETRY('POINT(1 2)'), [0, 0, 1, 1]) AS hilbert1, ST_HILBERT(TO_GEOMETRY('POINT(5 5)'), [0, 0, 5, 5]) AS hilbert2;

╭───────────────────────────╮
│   hilbert1  │   hilbert2  │
├─────────────┼─────────────┤
│  2863311530 │  2863311530 │
╰───────────────────────────╯

GEOGRAPHY examples

SELECT ST_HILBERT(TO_GEOGRAPHY('POINT(113.15 23.06)')) AS hilbert1, ST_HILBERT(TO_GEOGRAPHY('POINT(116.25 39.54)')) AS hilbert2;

╭───────────────────────────╮
│   hilbert1  │   hilbert2  │
├─────────────┼─────────────┤
│  3070259060 │  3033451300 │
╰───────────────────────────╯

SELECT ST_HILBERT(TO_GEOGRAPHY('POINT(113.15 23.06)'), [73, 4, 135, 53]) AS hilbert1, ST_HILBERT(TO_GEOGRAPHY('POINT(116.25 39.54)'), [73, 4, 135, 53]) AS hilbert2;

╭───────────────────────────╮
│   hilbert1  │   hilbert2  │
├─────────────┼─────────────┤
│  3533607194 │  2330429279 │
╰───────────────────────────╯