Re: [HACKERS] Optimizer is fixed, and faster

> I have fixed the optimizer, and it is working properly again, and faster
> too.
> 
> 
> -- 
>   Bruce Momjian                        |  http://www.op.net/~candle
>   maillist@candle.pha.pa.us            |  (610) 853-3000
>   +  If your life is a hard drive,     |  830 Blythe Avenue
>   +  Christ can be your backup.        |  Drexel Hill, Pennsylvania 19026

Looks good Bruce.

Here are some explain results from the 6.4.2 release and the development tree.

Postgres 6.4.2:
---------------
QUERY: EXPLAIN
SELECT hosts.host,      passwords.login,      passwords.uid,      groups.grp,      passwords.gecos,
passwords.home,     passwords.shell
 
FROM   hosts,      passwords,      groups
WHERE  hosts.host_id = passwords.host_id AND      groups.host_id = passwords.host_id AND      groups.gid =
passwords.gid;
NOTICE:  QUERY PLAN:

Merge Join  (cost=30894.02 size=2358855 width=108) ->  Nested Loop  (cost=20459.89 size=278240 width=84)       ->
IndexScan using hosts_pkey on hosts  (cost=13.90 size=198 width=16)       ->  Index Scan using passwords_pkey on
passwords (cost=103.26 
 
size=154973 width=68) ->  Seq Scan  (cost=20459.89 size=0 width=0)       ->  Sort  (cost=164.82 size=0 width=0)
             ->  Seq Scan on groups  (cost=164.82 size=3934 width=24)
 

Development Tree:
-----------------
QUERY: EXPLAIN
SELECT hosts.host,      passwords.login,      passwords.uid,      groups.grp,      passwords.gecos,
passwords.home,     passwords.shell
 
FROM   hosts,      passwords,      groups
WHERE  hosts.host_id = passwords.host_id AND      groups.host_id = passwords.host_id AND      groups.gid =
passwords.gid;
NOTICE:  QUERY PLAN:

Hash Join  (cost=4309.91 size=40 width=108) ->  Nested Loop  (cost=4291.52 size=40 width=92)       ->  Seq Scan on
groups (cost=160.82 size=3934 width=24)       ->  Index Scan using passwords_host_id_key on passwords  (cost=1.05 
 
size=154973 width=68) ->  Hash  (cost=0.00 size=0 width=0)       ->  Seq Scan on hosts  (cost=8.53 size=198 width=16)

-Ryan