Re: could not open relation - why?

> Oh, I assumed you had reason to think that the error message came from
> autovacuum. It could easily have been the same situation except two
> unrelated processes.
Surely my mistake in error reporting. Just cut out the "surrounding lines"
from the log; like in contextual diff :(

> What indeed happens alot in this database is the creation and the dropping
> > of temp tables (the later automagically at the end of a connection, I
> > assume)
>
> Hmm ... but why would one process be trying to open another one's temp
> table? The built-in stuff tries to avoid that, for the most part.
> What was that user doing, exactly, when he got the error?

"exactly" is a difficult question: he was creating a form. This form is
build out of 5-7 main queries, which touch around 60% of the tables in the
database. And one of these queries failed with this "cannot access" message
appearing.

My reason for suspecting the temp tables is the coded process of:

1) connect to database
2) on this connection, create a temp table carrying the user-id
3) on this connection, create a temp table carrying a quarant-level
4) prepare a hanfull of quereies for this connection
5) query lots of tables and views

the views are something like

select col1, col2, col3
from
mastertable
where now() >= validfrom and now() <= validuntill
and mastertable.quarantlevel=get_quarant()

(with get_quarant() a function looking up the current value within the
connections temp_table)

As the connections are handled in a pool, and the runtimesystem is able to
close them (together with the temp tables), those where my suspects.

>You
> >could try turning on log_error_statement so you could see what SQL
> >operation is provoking the error; that might help figure it out.

I put in

log_min_error_statement = error

and feel better prepared for the next appearing error. This error occurred
with a frequency of aroound once every month; so it will be some time until
I see it again.

Thanks for all the information and help,

Harald

--
GHUM Harald Massa
persuadere et programmare
Harald Armin Massa
Reinsburgstraße 202b
70197 Stuttgart
0173/9409607
-
Let's set so double the killer delete select all.