'''Recovers from errors.

    Only works under PostgreSQL (uses INSERT RETURNING).

    '''

    if pkey_ == None: pkey_ = pkey(db, table, recover=True)

    try:

    @return sql_gen.Col Where the output pkeys are made available

    '''

    out_table = sql_gen.as_Table(out_table)

    def log_debug(msg): db.log_debug(msg, level=1.5)

    def col_ustr(str_):

    insert_in_pkeys = insert_pkeys_table('in')

    # Do inserts and selects

    while True:

        if limit_ref[0] == 0: # special case

            log_debug('Creating an empty pkeys table')