Michel,

You should examine the query plan. If you see table scans on large tables it's most definately bad. If you see it estimating more rows than you think should be output by a step then you may need to HINT the SQL to get it to use a better index for a JOIN or a WHERE. And that assumes you have an index that can be used to optimize the piece.

>The simple join was not optimized. I had results in 0.3 seconds where I get results in 0.001 second with the 2nd approach. But, this seems to create a deadlock. So, I will use the EXISTS approach and we'll see how it goes.