Comparison of two tables in Teradata

Question

I'd need to compare two tables in Teradata SQL.

A sample of the two tables is

Table 1

User  Date          Ind1    Ind2
12   2010-05-23     Y       N
12   2010-06-23     Y       Y
12   2010-07-23     Y       N
23   2010-04-23     N       N
23   2010-05-23     N       N
23   2010-06-12     Y       N

Table 2

User  Date          Ind1    Ind2
12   2010-05-23     Y       N
12   2010-06-23     Y       Y
12   2010-07-23     N       N
24   2010-03-22     N       N
23   2010-04-23     N       Y
23   2010-05-23     N       Y
23   2010-06-12     Y       N

In this example, Table 1 differs from Table 2 because it has not the user 24 and also some values in Ind1 and Ind2 have changed. I usually compare data outside Teradata as I am not familiar with the code. Since the tables are very big, I'd like to know if there is a way to compare directly these tables there (for example, using join for users; I'm interested in looking at cases where there are more Ind1 =Y in Table 1).

Output expected:

Table 1 (where Ind1 and Ind2 have at least 1 Y)
    User  Date          Ind1    Ind2
    12   2010-05-23     Y       N
    12   2010-06-23     Y       Y
    12   2010-07-23     Y       N
    23   2010-06-12     Y       N

Table 2

User  Date          Ind1    Ind2
12   2010-06-23     Y       Y      /* it differs from Ind2 */
12   2010-07-23     N       N      /* it differs from both indicators */
24   2010-03-22     N       N     /* Not included in Table 1 */
23   2010-04-23     N       Y     /* it differs from Ind2 */
23   2010-05-23     N       Y     /* it differs from Ind2 */ 
23   2010-06-12     Y       N     /* it differs from Ind1 */

Answer 1

A typical method for comparing such tables would use full join :

select t1.*, t2.*
from table1 t1 full join
     table2 t2
     on t1.user = t2.user and t1.date = t2.date and
        t1.ind1 = t2.ind1 and t1.ind2 = t2.ind2
where t1.user is null or t2.user is null;

This returns the rows that are in each table that are not in the other. Note: It doesn't handle duplicate rows very well -- 1 duplicate in one table matches any number in the other table, for instance.

Answer 2

Your 1st result looks like a simple

select *
from table1
where ind1 = 'Y' 
   or ind2 = 'Y'

And the 2nd seems to be a set operation:

select *
from table2

except

select *
from table1

If there are duplicate rows, EXCEPT ALL might be what you want. If there are no duplicates it might still be more efficient than EXCEPT, you should try it.