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From: Martijn van Oosterhout <[email protected]>
To: Gurjeet Singh <[email protected]>
Cc: Tom Lane <[email protected]>
Cc: Pavel Stehule <[email protected]>
Cc: PGSQL General <[email protected]>
Cc: PGSQL Hackers <[email protected]>
Subject: Re: [HACKERS] ERROR: failed to find conversion function from "unknown" to text
Date: Tue, 6 Jan 2009 23:13:41 +0100
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>
References: <[email protected]>
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On Tue, Jan 06, 2009 at 11:13:59PM +0530, Gurjeet Singh wrote:
> If we consider the second branch of UNION ALL of both the queries above, if
> "select '' " yields a text column, then so should a "select * from (select
> '')".

The problem is ofcourse that "select ''" doesn't produce a text column
in postgres. This generally works fine, except in the case of UNION
where none of the branches provide the necessary type info.

Have a nice day,
-- 
Martijn van Oosterhout   <[email protected]>   http://svana.org/kleptog/
> Please line up in a tree and maintain the heap invariant while 
> boarding. Thank you for flying nlogn airlines.


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