Re: postgres external table

Yes. We get quite a few files as 'feeds' from external systems. Once the
files are in our network, we know that no changes will happen to those
files. We access them using Oracle external tables and process them (the
data, after some processing, end up in other real tables). If external
tables were not there, we would have had to schedule some job to load
these files.
Jayadevan

From: Greg Stark <gsstark(at)mit(dot)edu>
To: Craig Ringer <craig(at)postnewspapers(dot)com(dot)au>
Cc: Vincenzo Romano <vincenzo(dot)romano(at)notorand(dot)it>, Tom Lane
<tgl(at)sss(dot)pgh(dot)pa(dot)us>, Greg Smith <greg(at)2ndquadrant(dot)com>, Amy Smith
<vah123(at)gmail(dot)com>, pgsql-general(at)postgresql(dot)org
Date: 01/19/2010 04:37 PM
Subject: Re: [GENERAL] postgres external table
Sent by: pgsql-general-owner(at)postgresql(dot)org

On Tue, Jan 19, 2010 at 4:41 AM, Craig Ringer
<craig(at)postnewspapers(dot)com(dot)au> wrote:
> How can that work without a transactional file system, though? If the
> external process writes to the file while you're half-way through
reading
> it, what's the database to do? In general, how do external tables cope
with
> the fact that they're on non-transactional storage?

Well if you use mv to replace the old file with the new one then it
should be safe. Unless your query involves opening the table multiple
times or your transactions are more complex than a single query...

--
greg

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