in 0.12, you have to concat the result of selecting multiple criteria (keeping in mind that you may generate duplicates)
In [9]: pd.concat([store.select('testVar1', where=('A > 0', 'index >= 20131017')),
store.select('testVar1', where=('B > 0', 'index >= 20131017'))]).drop_duplicates().sort_index()
Out[9]:
A B C
2013-10-17 0.156248 0.085911 10.238636
2013-10-22 -0.125369 0.335910 10.865678
2013-10-23 -2.531444 0.690332 12.335883
2013-10-24 -0.266777 0.501257 13.529781
2013-10-25 0.815413 -0.629418 14.690554
2013-10-28 0.383213 -0.587026 13.589094
2013-10-31 1.897674 0.361764 14.595062
[7 rows x 3 columns]
In 0.13/master (0.13rc1 is out!), you can just do a very natural query
In [10]: store.select('testVar1', where='(A > 0 | B > 0) & index >= 20131017')
Out[10]:
A B C
2013-10-17 0.156248 0.085911 10.238636
2013-10-22 -0.125369 0.335910 10.865678
2013-10-23 -2.531444 0.690332 12.335883
2013-10-24 -0.266777 0.501257 13.529781
2013-10-25 0.815413 -0.629418 14.690554
2013-10-28 0.383213 -0.587026 13.589094
2013-10-31 1.897674 0.361764 14.595062
[7 rows x 3 columns]