Re: query optimization scenarios 17,701 times faster!!!

On Wed, Apr 23, 2003 at 02:04:02PM -0400, Robert Dyas wrote:
> 
> The following is a list of query pairs (one fast, one slow) that must
> produce identical results by definition (and do), but have very different
> execution times.

I think what you see is what is described in the documentation
too.  If you use outer joins, it will do them in the order of the
query.  I think the reason for that was that the SQL standard
required it.

So if you put your query in an other order, you will get a
different result.

I believe that they removed that restriction in the last/cvs
version of PosgresQL.

> Especially the last example.

Where it's joining alot of tables it doesn't use in the first
place.  You even removed the conditions on how to join the
tables.


Kurt