presto-tpcds/src/main/java/io/prestosql/plugin/tpcds/TpcdsMetadata.java/TpcdsMetadata/getSchemaNames
class TpcdsMetadata:    private List<String> getSchemaNames(ConnectorSession session, Optional<String> schemaName)
    {
        if (!schemaName.isPresent()) {
            return listSchemaNames(session);
        }
        if (schemaNameToScaleFactor(schemaName.get()) > 0) {
            return ImmutableList.of(schemaName.get());
        }
        return ImmutableList.of();
    }