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DuckDB Extensions All extensions GeoSilo

Encoding functions in the GeoSilo DuckDB extension

Function category

Encoding

3 functions

Encode/decode between [`GEOMETRY`](https://duckdb.org/docs/extensions/spatial) and the compact GEOSILO BLOB format, plus header inspection without a full decode. The `GEOSILO` column type drives most of this transparently — these functions are for explicit BLOB pipelines and Arrow IPC interchange.

geosilo_decode

Scalar function Encoding
Signature
geosilo_decode(col0: BLOB | GEOSILO) → GEOMETRY
Arguments (Positional)
Argument col0 Type BLOB | GEOSILO
2 concrete types
BLOBGEOSILO
Mode Positional Description
Description

Decode a GEOSILO blob back into a standard GEOMETRY. Most callers don't need to call this directly — the implicit GEOSILO → GEOMETRY cast runs it on demand for any ST_* function that doesn't have a native GEOSILO overload (e.g. ST_Buffer, ST_Union, ST_AsText).

1 Round-trip a polygon through the encoding 
SELECT ST_AsText(
  geosilo_decode(geosilo_encode(ST_GeomFromText('POLYGON((0 0,10 0,10 10,0 10,0 0))')))
);
Related functions

geosilo_encode

Scalar function Encoding
Signature
2 overloaded forms · click to inspect
Arguments (Positional)
Argument col0 Type GEOMETRY Mode Positional Description
Description

Encode a GEOMETRY into the compact GEOSILO format and return a BLOB. With one argument, the integer scale is derived from the geometry's CRS — degrees default to 1e7 (≈1 cm), projected meters to 100 (1 cm). With two arguments, the second explicitly sets the scale.

1 Default scale (auto from CRS, or `1e7` if absent) 
SELECT geosilo_encode(ST_GeomFromText('POINT(1 2)'));
2 Explicit scale — UTM / Web Mercator data, 1 cm precision 
SELECT geosilo_encode(geom, 100) FROM utm_data;
Related functions

geosilo_metadata

Scalar function Encoding
Signature
geosilo_metadata(col0: GEOSILO | BLOB) → STRUCT(geometry_type VARCHAR, vertex_type VARCHAR, scale BIGINT)
Arguments (Positional)
Argument col0 Type GEOSILO | BLOB
2 concrete types
BLOBGEOSILO
Mode Positional Description
Description

Read a GEOSILO blob's header without decoding the geometry. Returns STRUCT(geometry_type VARCHAR, vertex_type VARCHAR, scale BIGINT). Useful for filtering by geometry type or auditing the integer scale of a stored column before any heavy spatial work.

1 Inspect the header of stored silo blobs 
SELECT geosilo_metadata(silo_blob) AS meta
FROM compact_table
LIMIT 5;
-- {'geometry_type':'POLYGON','vertex_type':'XY','scale':10000000}
Related functions