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 200511292015.jATKFLe17985@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  (Simon Riggs <simon@2ndquadrant.com>)
List pgsql-hackers
Tom Lane wrote:
> Bruce Momjian <pgman@candle.pha.pa.us> writes:
> > Tom Lane wrote:
> >> 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? 
> 
> Log, yes, unless it's a temp table.  The point is we could avoid taking
> buffer content locks.  Come to think of it, we could implement that
> trivially in the heapam.c routines; it would then apply to any table
> update whether generated by COPY or otherwise.

I am confused.  This optimization prevents locking, but still requires
logging?

> > Yes, I guess, but do we want to propogate that into pg_dump output?  I
> > would think not.
> 
> Exactly my point; we don't have to change any syntax, so pg_dump
> doesn't care.

But can pg_dump take advantage of this optimization?

--  Bruce Momjian                        |  http://candle.pha.pa.us pgman@candle.pha.pa.us               |  (610)
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