Amir Becher <abecher@yahoo.com> writes:
> Here is an example of the misbehavior that I am
> seeing:
> [snip]
> The main point is that "column_a" is the wrong number.
Hmm. This looks like you must have an index entry pointing at the wrong
heap tuple. Which is not something we hear of regularly, and certainly
not an error that I'd expect to see appearing in isolation.
You didn't say in so many words, but should I take it that (a) this
pattern of misbehavior (wrong row returned) occurs repeatedly for you,
and (b) there are no other signs of problems (backend unexpectedly
quits, strange error messages, that sort of thing)?
I can't really think of any plausible mechanism for this to happen,
except for the index and table files getting out of sync somehow.
Are you doing anything that operates directly on the database files
(for example, doing backup/restore with cp or tar or some such)?
regards, tom lane