'''For kw_args, see tables()'''

    for table in tables(db, schema, **kw_args): truncate(db, table, schema)

    '''Creates a copy of a temp table which is distinct on the given columns.

    Adds an index on table's distinct_on columns, to facilitate merge joins.

    @param distinct_on If empty, creates a table with one row. This is useful if

        your distinct_on columns are all literal values.

    @param joins The joins to use when creating the new table

    @return The new table.

    '''

    if joins == None: joins = [table]

    else: add_index(db, distinct_on, table) # for join optimization

    insert_select(db, new_table, None, mk_select(db, joins,

        order_by=None, limit=limit))

    analyze(db, new_table)