presto-iceberg/src/main/java/io/prestosql/plugin/iceberg/IcebergMetadata.java/IcebergMetadata/dropSchema
class IcebergMetadata:    @Override
    public void dropSchema(ConnectorSession session, String schemaName)
    {
        // basic sanity check to provide a better error message
        if (!listTables(session, Optional.of(schemaName)).isEmpty() ||
                !listViews(session, Optional.of(schemaName)).isEmpty()) {
            throw new PrestoException(SCHEMA_NOT_EMPTY, "Schema not empty: " + schemaName);
        }
        metastore.dropDatabase(new HiveIdentity(session), schemaName);
    }