Re: Oracle SQL Tuning

The Minus won't use the primary keys as theres no explicit join between the two tables.

You could try the following:

SELECT a.*
FROM table_a a, table_b b
WHERE a.id = b.id (+)
AND b.rowid is null;

Regards, Andy

Patrick Lo <cylo_at_vtc.edu.hk> wrote in message news:<3D24FF7F.2216FD9B_at_vtc.edu.hk>...
> Hi,
>
> I got two data structure identifical tables table_a and table_b. Table
> table_a contains not more than 100 records while Table table_b contains
> more than 100000 records. Both tables have the same Primary Key.
>
> Now, I am going to "diff" the records in table_a with the ones in
> table_b and show the different records in table_a. Someone told me that
> I could use the following SQL statement to "diff" the records :
>
> SELECT * FROM table_a
>
> MINUS
>
> SELECT * FROM table_b
>
> He told me that it was efficient to find the difference of the two
> identificals. As I have not used this way to compare two sets of
> records, I went ahead to run the SQL statement. However, I found that
> the above SQL statement ran a long long time, even though the number
>
> Can the above statement use the Primary Key as indexing?
Received on Fri Jul 05 2002 - 05:21:50 CDT