Re: optimizer - Mailing list pgsql-admin
| From | Zhang, Anna |
|---|---|
| Subject | Re: optimizer |
| Date | |
| Msg-id | 5511D658682A7740BA295CCF1E1233A635A861@vsvapostal2.bkup3 Whole thread Raw |
| In response to | optimizer ("Zhang, Anna" <azhang@verisign.com>) |
| Responses |
Re: optimizer
|
| List | pgsql-admin |
>Is the estimate above (1.5M rows) reasonable? If so, it's probably
>doing the right thing. If not, what version are you using and are
>there any very common values that may throw off the estimates; what
>does select * from pg_statistic where starelid=(select oid from
>pg_class where relname='domain'); give?
select * from pg_statistic where starelid=(select oid from pg_class where
relname='domain');
starelid | staattnum | staop | stanullfrac | stacommonfrac |
stacommonval | staloval |
stahival
-----------+-----------+-------+-------------+---------------+--------------
--------------+------------------------------+------------------------------
-----------------------------------
749413081 | 1 | 664 | 0 | 7.02145e-08 | UPSPWR-DOM
| 000000000000000000000-N3-DOM | ZZZZZZZZZZZZZZZZZZZZZ9-DOM
749413081 | 2 | 664 | 0 | 7.02145e-08 | UPSPWR
| 00 |
ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ
749413081 | 3 | 664 | 0 | 0.728349 | COM
| ARPA | WS
749413081 | 4 | 664 | 0 | 0.107595 | NAMEZERO.COM
| ` | ambassador blinds
749413081 | 5 | 664 | 0 | 0.107594 | 51 University
Ave, Suite K | - | zzzzzzzzzzzzzzzzzz
zzzzzzzzzzzzzzzz, zzzzzzzzzzz 325698
749413081 | 6 | 664 | 0.312378 | 0.107716 | LOS GATOS
| - | Murray
749413081 | 7 | 664 | 0.312378 | 0.227842 | CA
| AA | WY
749413081 | 8 | 664 | 0.312119 | 0.107774 | 95030
| 00005 | 99995
749413081 | 9 | 664 | 0.00980173 | 0.687646 | US
| AC | ZW
(9 rows)
The column holdername is not common, same holdername may have a few records.
I am running postgres 7.2, for pg_statistic table I really no idea what each
column means, if you get some clue from above query result please give me an
advise. Thanks for reply.
Anna Zhang
pgsql-admin by date: