is_empty(geom), check if a geometry is empty (geometry that contain no coordinates)is_empty_or_null(geom), check if a geometry is empty or NULL (does not have geometry)hash, cryptographic hashes functions using QCryptographicHash. Use case is the same as PgCrypto but in client side for all supported format.This feature was developed by Loïc Bartoletti (Oslandia)