SQL Query Analyzer is an interactive, graphical tool that enables a database administrator or developer to write queries, execute multiple queries simultaneously, view results, analyze the query plan, and receive assistance to improve the query performance.
The best SQL optimizers are humans. If possible, talk to a DBA who can help you work out the issue. In general, database optimization tools may only help you find the troublesome queries, but rarely how to fix them. The vast majority of the time this involves adding an index to a particular column (Hash or Btree)
I recommend find a process that's taking a long time. Then isolate the exact query that's taking a long time. Then start stripping away conditions and joins of the query until you find the one condition or one join that's slowing it down. That is often where you need to insert an index. Resolving some slow queries could involve refactoring your database schema or even adding denormalized (see: materialized views) data. There's no magic tool that's going to solve it for you, you just need to be a detective.
As a side note, I'm not against query optimization tools, in some cases they can find things you'd never think of. I just feel the best query optimizers are humans, since 99 times out of a 100 a single index will resolve the slowdown.