Re: AW: Issue NOTICE for attempt to raise lock level? - Mailing list pgsql-hackers

From Tom Lane
Subject Re: AW: Issue NOTICE for attempt to raise lock level?
Date
Msg-id 6358.973616757@sss.pgh.pa.us
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In response to AW: Issue NOTICE for attempt to raise lock level?  (Zeugswetter Andreas SB <ZeugswetterA@wien.spardat.at>)
List pgsql-hackers
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


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