def _render_sources(dataset, tables):
    """Render the source part of a query.

    Args:
        dataset: the data set to fetch log data from.
        tables: the tables to fetch log data from.

    Returns:
        a string that represents the from part of a query.
    """

    return "FROM " + ", ".join(
        ["[%s.%s]" % (dataset, table) for table in tables])