Re: Using multi-row technique with COPY - Mailing list pgsql-hackers

From Bruce Momjian
Subject Re: Using multi-row technique with COPY
Date
Msg-id 200511291950.jATJoZ513641@candle.pha.pa.us
Whole thread Raw
In response to Re: Using multi-row technique with COPY  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: Using multi-row technique with COPY  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
Tom Lane wrote:
> Bruce Momjian <pgman@candle.pha.pa.us> writes:
> > One idea for default behavior would be to use EXCLUSIVE when the table
> > is zero size.  I think that would do pg_dump and most of the user cases,
> > and of course users could override the default by using a keyword.  We
> > could emit a NOTICE if an an exclusive lock is used without an EXCLUSIVE
> > keyword.  One problem I see is that there is no way to insure zero size
> > without a lock that blocks other writers.  Is that reliable?
> 
> No, and if you try to upgrade your lock after checking, you create a
> deadlock problem.
> 
> Something that would probably be reasonable, and require *no* weird new
> syntax, is to shortcut in a COPY into a table created in the current
> transaction.  I believe we still keep a flag in the relcache indicating
> whether that's the case ...

So if the table is created in the current transaction, we don't log? 
Yes, I guess, but do we want to propogate that into pg_dump output?  I
would think not.

--  Bruce Momjian                        |  http://candle.pha.pa.us pgman@candle.pha.pa.us               |  (610)
359-1001+  If your life is a hard drive,     |  13 Roberts Road +  Christ can be your backup.        |  Newtown Square,
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