Thread: AW: Issue NOTICE for attempt to raise lock level?

> I am working on eliminating the "relation NNN modified while in use"
> misfeature by instead grabbing a lock on each relation at first use
> in a statement, and holding that lock till end of transaction. 

As anticipated, I object :-) 
If you do this you will most likely add the code to the wrong places, 
since what we really need is a lock for the duration of one statement only.

Otherwise you will only fix this situation for those cases where the application 
is actually inside a transaction. And this is (and hopefully stays) not mandatory. 

Additionally we would have the discussed lockout of admin tasks ...

Andreas

Zeugswetter Andreas SB <ZeugswetterA@wien.spardat.at> writes:
>> I am working on eliminating the "relation NNN modified while in use"
>> misfeature by instead grabbing a lock on each relation at first use
>> in a statement, and holding that lock till end of transaction. 

> As anticipated, I object :-) 

Your objection is founded on two misunderstandings.  In the first place,
we are *always* inside a transaction when executing a query.  It may be
an implicit one-statement transaction, but it's still a transaction.
In the second place, we already grab locks that we do not release till
end of xact for all user-level queries.  The problem is that we grab
them too late, ie, in the executor.  I'm just planning to move up the
grab till first use.
        regards, tom lane