- A BLOB for the well-known binary representation of the spatial type.
The maximum size of wkb is approximately 16 MB (the exact maximum is 16 MB - 1 KB), allowing for a representation of approximately one million points.
For details on well-known binary formats, see Well-Known Binary Format.
- An optional INTEGER value for a spatial reference system identifier.
If this argument is omitted, the spatial reference system identifier is set to 0.