Re: [PATCH 4/4] Add tests to dblink covering use of COPY TO FUNCTION
От | Jeff Davis |
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Тема | Re: [PATCH 4/4] Add tests to dblink covering use of COPY TO FUNCTION |
Дата | |
Msg-id | 1259355349.19289.536.camel@jdavis обсуждение исходный текст |
Ответ на | Re: [PATCH 4/4] Add tests to dblink covering use of COPY TO FUNCTION (Simon Riggs <simon@2ndQuadrant.com>) |
Список | pgsql-hackers |
On Fri, 2009-11-27 at 13:39 +0000, Simon Riggs wrote: > On Tue, 2009-11-24 at 22:13 -0800, Jeff Davis wrote: > > > My disagreement with the row-by-row approach is more semantics than > > performance. COPY translates records to bytes and vice-versa, and your > > original patch maintains those semantics. > > The bytes <-> records conversion is a costly one. Anything we can do to > avoid that in either direction will be worth it. I would regard > performance as being part/most of the reason to support this. > Right. I was responding to an idea that copy support sending records from a table to a function, or from a function to a table, which is something that INSERT/SELECT can already do. Our use case is a table to a remote table, so it would go something like:1. COPY TO WITH BINARY on local node2. stream output bytes from #1 to remote node3. COPY FROM WITH BINARY on remotenode The only faster mechanism that I could imagine is sending the records themselves, which would be machine-dependent. Regards,Jeff Davis
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