Your intent is good but you may wish to verify your answers
"SELECT table_name,index_name FROM user_constraints"
I believe user_constraints is Oracle specific.
Also
"Subqueries can often be re-written to use a standard outer join,
resulting in faster performance. As we may know, an outer join uses the
plus sign (+) operator to tell the database to return all non-matching
rows with NULL values. Hence we combine the outer join with a NULL test
in the WHERE clause to reproduce the result set without using a
sub-query. "
The + is also Oracle specific syntax for outer joins. It's not ANSI or SQL Server specific.
