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Date: Tue, 6 Jan 2009 23:13:41 +0100
From: Martijn van Oosterhout <kleptog@svana.org>
To: Gurjeet Singh <singh.gurjeet@gmail.com>
Cc: Tom Lane <tgl@sss.pgh.pa.us>, Pavel Stehule <pavel.stehule@gmail.com>,
	PGSQL General <pgsql-general@postgresql.org>,
	PGSQL Hackers <pgsql-hackers@postgresql.org>
Subject: Re: [HACKERS] ERROR: failed to find conversion function from
	"unknown" to text
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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,
--=20
Martijn van Oosterhout   <kleptog@svana.org>   http://svana.org/kleptog/
> Please line up in a tree and maintain the heap invariant while=20
> boarding. Thank you for flying nlogn airlines.

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