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

From Simon Riggs
Subject Re: Using multi-row technique with COPY
Date
Msg-id 1133170776.2906.360.camel@localhost.localdomain
Whole thread Raw
In response to Re: Using multi-row technique with COPY  (Martijn van Oosterhout <kleptog@svana.org>)
Responses Re: Using multi-row technique with COPY  (Martijn van Oosterhout <kleptog@svana.org>)
List pgsql-hackers
On Mon, 2005-11-28 at 09:40 +0100, Martijn van Oosterhout wrote:
> On Sun, Nov 27, 2005 at 05:45:31PM -0500, Tom Lane wrote:
> > Simon Riggs <simon@2ndquadrant.com> writes:
> > > COPY FROM can read in sufficient rows until it has a whole block worth
> > > of data, then get a new block and write it all with one pair of
> > > BufferLock calls.
> > 
> > > Comments?

> Whatever happened to that idea to build as entire datafile with COPY or
> some external tool and simply copy it into place and update the
> catalog?

What's wrong with tuning the server to do this? 

Zapping the catalog as a normal operation is the wrong approach if you
want a robust system. All actions on the catalog must be under tight
control.

Most other RDBMS support a "fast path" loader, but all of them include
strong hooks into the main server to maintain catalog correctly. That is
one approach, but it requires creation of an external API - which seems
more work, plus a security risk. Copying data in a block at a time is
the basic technique all use.

I never discuss implementing features that other RDBMS have for any
other reason than than a similar use case exists for both. There are
many features where PostgreSQL is already ahead.

Best Regards, Simon Riggs



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