Complex queries

[Anil]

HI,

are there any recommendations (other than affinity) for complex queries
like below.

SELECT DISTINCT b.id, b.filename, a1.name
FROM a a1
JOIN b
  ON b.id = a1.id
LEFT JOIN (select a.id, max(rank) latest from a group by a.id) a2
  ON a2.id = a1.id

Thanks.