sql select help required

I have a table T1 with the following columns
( A Char, B char, C Char, D char, E Date)

I have the data for A and B and I want to retrieve the records with the maximum date, The columns C and D will repeat for a combination of A, B.

I can write a sql with a subquery like this , but due to performance reasons I dont prefer a subquery
Select C, D, E from T where A = n and B= m and T = ( select Max(E) from T where A= n and B= m)

Performace is very important for this query. Please help.

Thanks,
Sumanb

maybe something like:

SELECT C, D, E FROM T1 WHERE A='n' AND B='m', ORDER BY E DESC LIMIT 1;

this will order the items that apply (A=n and B=m), with the biggest on top, then only take the first (one with the highest date)

Alternatively, if what you mean by
is that C and D are the same for all lines in which A=n and B=m (so only E is different) you can use:

SELECT C, D, MAX(E) FROM T1 WHERE A='n' AND B='m' GROUP BY a, b);

only use this if that's true though, ontherwise you'll get wrong results.

Hi Sumanb

I prefer doing this query using INNER JOIN. It will be much quicker

Raj