Re: SELECT returning too many rows (?)

rob  writes:
> processing=# select oid,  ctid, xmin, cmin, xmax, cmax from q_certs
> where oid = 15282219 ;
>    oid    | ctid  |   xmin    |   cmin    |   xmax    |   cmax   
> ----------+-------+-----------+-----------+-----------+-----------
>  15282219 | (3,5) | 174011432 |         1 |         1 | 174214469
>  15282219 | (5,5) | 174011432 |         1 |         1 | 174214469
>  15282219 | (7,5) | 174011432 | 174700216 | 174700216 |         1

This looks to me like malfeasance of a VACUUM FULL: the reason there
are multiple copies is that VACUUM FULL was trying to move the row
around, and somehow you ended up with all three copies marked "good",
when there should have been only one "good" copy at any instant.

So: (1) have you had any system crashes recently?  (2) what sort of
disk hardware is this running on?  I'm wondering about IDE drives
with write caching enabled :-(

			regards, tom lane