From: Tom Lane <tgl@sss.pgh.pa.us>
To: Gunther Schadow <gunther@aurora.regenstrief.org>
Cc: pgsql-sql <pgsql-sql@postgresql.org>
Subject: Re: Support for distributed queries with semijoins could be possible, if ...
Date: Sun, 09 Jun 2002 15:00:58 -0400
Message-ID: <6693.1023649258@sss.pgh.pa.us> (raw)
In-Reply-To: <3D0393D0.2070208@aurora.regenstrief.org>
References: <3D0393D0.2070208@aurora.regenstrief.org>
Gunther Schadow <gunther@aurora.regenstrief.org> writes:
> SELECT fever.patient_id AS patient_id,
> fever.value AS fever,
> wbc.value AS wbc
> FROM (SELECT patient_id, value
> FROM STDIN) fever
> INNER JOIN Observation wbc
> ON fever.patient_id = wbc.patient_id
> WHERE wbc.type_code = 'WHITE BLOOD CELL COUNT'
> AND wbc.value < 1000;
A much more direct way of doing it is to leave the client out of the
loop. The data from system A could be pulled directly into system B,
using e.g. Joe Conway's contrib/dblink package. dblink is pretty
awkward to use in 7.2 but in 7.3 it should be a lot nicer --- the
returned data can be treated as a table function...
regards, tom lane
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To: pgsql-sql@postgresql.org
Cc: tgl@sss.pgh.pa.us, gunther@aurora.regenstrief.org
Subject: Re: Support for distributed queries with semijoins could be possible, if ...
In-Reply-To: <6693.1023649258@sss.pgh.pa.us>
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