**Benchmark setup**

.. code-block:: python

    from pandas_vb_common import *
    
    N = 10000
    K = 10
    
    key1 = np.array([rands(10) for _ in xrange(N)], dtype='O').repeat(K)
    key2 = np.array([rands(10) for _ in xrange(N)], dtype='O').repeat(K)
    
    df = DataFrame({'key1' : key1, 'key2' : key2,
                    'value' : np.random.randn(N * K)})
    

**Benchmark statement**

.. code-block:: python

    df.sort_index(by=['key1', 'key2'])

**Performance graph**

.. image:: vbench/figures/frame_sort_index_by_columns.png
   :width: 6in