RE: [SQL] Joining bug????

>     BTW:  You  might want to take a look at the new documentation
>     of the rule system to understand how views work in detail.
>
I think I'll do that.  I'd love to be able to help you for the rule
rewrite for v6.5 .

>     It could only be the parse stage. After the  rule  system  is
>     through  with the query, the parsetree given to the optimizer
>     is exactly the same  as  if  you  typed  in  the  query  that
>     accesses the real tables.  Having a view
>
>         CREATE VIEW v1 AS SELECT t1.a, t2.b FROM t1, t2
>             WHERE t1.a = t2.a;
>
>     and doing a
>
>         SELECT * FROM v1 WHERE a = 'something';
>
>     is 100% the same as
>
>         SELECT t1.a, t2.b FROM t1, t2
>             WHERE t1.a = 'something'
>               AND t1.a = t2.a;
>
>     The  optimizer  will  get exactly the same parsetree and will
>     generate the same plan then. So the timing difference  cannot
>     be in the optimizer or executor.
>
>     But  it's  interesting.  I'll  do some tests on it and try to
>     find out whether parsing of complicated WHERE clauses is that
>     costly  that  it  can be the reason. Seems the rule system is
>     quicker than the parser :-)
>
What kind of speed increases are people seeing in their queries?
I've actually never created a view in PostgreSQL (say he with head hung
low).


> Jan
    -DEJ