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

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: Zeugswetter Andreas SB <ZeugswetterA(at)wien(dot)spardat(dot)at>
Cc: pgsql-hackers(at)postgresql(dot)org
Subject: Re: AW: Issue NOTICE for attempt to raise lock level?
Date: 2000-11-07 17:05:57
Message-ID: 6358.973616757@sss.pgh.pa.us
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Zeugswetter Andreas SB <ZeugswetterA(at)wien(dot)spardat(dot)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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