From: Tom Lane <tgl@sss.pgh.pa.us>
To: Dean Gibson (DB Administrator) <postgresql4@ultimeth.com>
Cc: pgsql-sql <pgsql-sql@postgresql.org>
Subject: Re: What does "merge-joinable join conditions" mean ????
Date: Sun, 15 Jan 2006 16:58:28 -0500
Message-ID: <17050.1137362308@sss.pgh.pa.us> (raw)
In-Reply-To: <43CAAFA6.6050001@ultimeth.com>
References: <43CAAFA6.6050001@ultimeth.com>
"Dean Gibson (DB Administrator)" <postgresql4@ultimeth.com> writes:
> I have a FULL JOIN between two simple tables, and am getting the message
> " Query failed: ERROR: FULL JOIN is only supported with merge-joinable
> join conditions"
> I'd be glad to fix this in my query if I knew what the #@!! it meant.
The join condition(s) of a FULL JOIN have to be mergejoinable, which
basically means an equality relation between sortable (btree-indexable)
data types. You can see exactly which operators are mergejoinable with
a query like
select oid::regoperator from pg_operator where oprlsortop != 0;
regards, tom lane
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To: pgsql-sql@postgresql.org
Cc: tgl@sss.pgh.pa.us, postgresql4@ultimeth.com
Subject: Re: What does "merge-joinable join conditions" mean ????
In-Reply-To: <17050.1137362308@sss.pgh.pa.us>
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