Limitations when using spatial data with Amazon Redshift - Amazon Redshift

Limitations when using spatial data with Amazon Redshift

The following are limitations when using spatial data with Amazon Redshift:

  • The maximum size of a GEOMETRY object is 1,048,447 bytes.

  • Amazon Redshift Spectrum doesn't natively support spatial data. Therefore, you can't create or alter an external table with a GEOMETRY column.

  • Data types for Python user-defined functions (UDFs) don't support the GEOMETRY data type.

  • You can't use a GEOMETRY column as a sort key or a distribution key for an Amazon Redshift table.

  • You can't use GEOMETRY columns in SQL ORDER BY, GROUP BY, or DISTINCT clauses.

  • You can't use GEOMETRY columns in many SQL functions.

  • You can't perform an UNLOAD operation on geometry columns into every format. You can UNLOAD GEOMETRY columns to text or comma-separated value (CSV) files. Doing this writes GEOMETRY data in hexadecimal EWKB format. If the size of the EWKB data is more than 4 MB, then a warning occurs because the data can't later be loaded into a table.

  • The supported compression encoding of GEOMETRY data is RAW.

  • When using JDBC or ODBC drivers, use customized type mappings. In this case, the client application must have information on which parameters of a ResultSet object are GEOMETRY objects. The ResultSetMetadata operation returns type VARCHAR.

The following nonspatial functions can accept an input of type GEOMETRY or columns of type GEOMETRY:

  • The aggregate function COUNT

  • The conditional expressions COALESCE and NVL

  • CASE expressions

  • The default encoding for GEOMETRY is RAW. For more information, see Compression encodings.