isbn	city	libname	a
007	Berkeley	Berkeley Public1	1
007	Berkeley	Berkeley Public2	1
000	New York	New York Public Libra	6
001	New York	NYC Lib	1
006	San Fran	San Fransisco Public	1
isbn	city	libname	a
007	Berkeley	Berkeley Public1	2
000	New York	New York Public Libra	2
f1	count(distinct t2.f2)	count(distinct 1,NULL)
1	0	0