Re: 8.4 open item: copy performance regression?

<div class="gmail_quote">On Mon, Jun 22, 2009 at 7:16 AM, Tom Lane <span dir="ltr"><<a
href="mailto:tgl@sss.pgh.pa.us">tgl@sss.pgh.pa.us</a>></span>wrote:<br /><blockquote class="gmail_quote"
style="border-left:1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"><div class="im">Alan Li
<<ahref="mailto:ali@truviso.com">ali@truviso.com</a>> writes:<br /> > How much concern is there for the
contentionfor use cases where the WAL<br /> > can't be bypassed?<br /><br /></div>If you mean "is something going to
bedone about it in 8.4", the<br /> answer is "no".  This is a pre-existing issue that there is no simple<br /> fix
for.<br/><br />                        regards, tom lane<br /><br /><br /></blockquote></div>No no, I am certainly not
implyinganything for the 8.4 timeframe.<br /><br />Moving forward, I imagine this being more of a problem for data
warehouseapplications, where bulk inserts occur on existing fact tables.  In this case, the WAL cannot be bypassed
(unlessthe bulk insert occurs on a newly created partition).  And since COPY is cpu-bound, it would perhaps be
advantageousto do parallel COPY's on the same table on multi-core systems, which won't work with WAL bypassing
either.<br/><br />Thanks, Alan<br />