Re: Seeking help with a query that takes too long

On Wed, 12 Nov 2003 08:34:50 -0500, "Nick Fankhauser"
<nickf@ontko.com> wrote:
>                                       ->  Index Scan using
>actor_full_name_uppercase on actor  (cost=0.00..6.01 rows=1 width=42)
                                                      ^^^^^^
>(actual time=37.62..677.44 rows=3501 loops=1)
                            ^^^^^^^^^
>                                             Index Cond:
>((actor_full_name_uppercase >= 'SANDERS'::character varying) AND
>(actor_full_name_uppercase < 'SANDERT'::character varying))
>                                             Filter:
>(actor_full_name_uppercase ~~ 'SANDERS%'::text)

Nick, can you find out why this row count estimation is so far off?

\x
SELECT * FROM pg_stats
 WHERE tablename='actor' AND attname='actor_full_name_uppercase';

BTW, there seem to be missing cases:
>  ->  Nested Loop  (cost=0.00..2214.66 rows=2 width=115)
>                   (actual time=59.05..119929.71 rows=5879 loops=1)
                                                       ^^^^
>        ->  Nested Loop  (cost=0.00..2205.26 rows=3 width=76)
>                         (actual time=51.46..66089.04 rows=5882 loops=1)
                                                            ^^^^

Servus
 Manfred