def version(*dbs):
    '''
    Server Version (select banner  from v$version)

    CLI Example:

    .. code-block:: bash

        salt '*' oracle.version
        salt '*' oracle.version my_db
    '''
    pillar_dbs = __salt__['pillar.get']('oracle:dbs')
    get_version = lambda x: [
        r[0] for r in run_query(x, "select banner from v$version order by banner")
        ]
    result = {}
    if dbs:
        log.debug('get db versions for: %s', dbs)
        for db in dbs:
            if db in pillar_dbs:
                result[db] = get_version(db)
    else:
        log.debug('get all(%s) dbs versions', len(dbs))
        for db in dbs:
            result[db] = get_version(db)
    return result