Re: Another seq scan instead of index question

On Tue, 07 Aug 2001, Tom Lane wrote:

> Your real problem is the bogus selectivity estimate. What version
> are you running? If 7.0, see contrib/likeplanning/. If 7.1, I'd
> be interested to see what you get from

I'm on 7.1
(PostgreSQL 7.1.2 on i686-pc-linux-gnu, compiled by GCC 2.95.4)

> select attname,attdispersion,s.*
> from pg_statistic s, pg_attribute a, pg_class c
> where starelid = c.oid and attrelid = c.oid and staattnum = attnum
> and relname = 'cdsongs';

That doesn't look good to me as it contains dodgy bytes...

attname | attdispersion | starelid | staattnum | staop | stanullfrac | stacommonfrac | stacommonval | staloval | stahival
---------+---------------+----------+-----------+-------+-------------+---------------+---------------+----------+--------------------------------------------------------------
songid | -1 | 61094022 | 1 | 97 | 0 | 2.3748e-07 | 1 | 1 | 4210874
cdid | 4.65505e-06 | 61094022 | 2 | 97 | 0 | 2.32731e-05 | 677 | 1 | 364477
track | 0.0231229 | 61094022 | 3 | 97 | 0 | 0.086018 | 0 | 0 | 97
song | 0.000647958 | 61094022 | 4 | 1066 | 0 | 0.00319886 | | | þöför amca
extt | 0.890813 | 61094022 | 5 | 664 | 0.937611 | 2.9685e-05 | The Residents | | ýòî ïðîéäåò - ëåòè íà âîñõîä,
À ÿ, òàê è áûòü, íà çàêàò.

The data came from freedb, translated to postgresql by a small C
program which I didn't write.

Nick

--
Part 3 MEng Cybernetics; Reading, UK http://www.nickpiper.co.uk/
Change PGP actions of mailer or fetch key see website 1024D/3ED8B27F
Choose life. Be Vegan :-) Please reduce needless cruelty + suffering !