On 7/11/06, A. Pagaltzis <[EMAIL PROTECTED]> wrote:
* Jay Sprenkle <[EMAIL PROTECTED]> [2006-07-10 17:30]:
> // - Use SQL Joins instead of using sub-queries
Not so fast there. I have accelerated queries by several 100
percent by turning joins into subqueries. On other occasions I
did so by turning subqueries into joins. The performance of joins
vs subqueries in any non-trivial query depends on a *lot* of
variables. You can't just say "use this one" or "use the other"
as a blanket statement.
I just did the test of that one. All things being equal I saw only
a 1%-4% difference between the performance of the two variants.
I don't think thats enough to even be worth looking at. Optimizations
that don't get you any significant benefit aren't worth doing.
