Page Comparison

Manually comparing the data between source and target and optionally applying the differences

Please see http://docs.oracle.com/cd/B28359_01/appdev.111/b28419/d_comparison.htm for the use of DBMS_COMPARISON to compare both datasets and generate SQL for the differences.

Another option is to run the following SQL: 

...

...

select count(*) 

from 

( 

( select * from tab1@source 

minus 

select * from tab1@target ) 

union all 

( select * from tab1@target 

minus 

select * from tab1@source ) 
)