Re: [HACKERS] ERROR: failed to find conversion function from "unknown" to text - Mailing list pgsql-general

From Gurjeet Singh
Subject Re: [HACKERS] ERROR: failed to find conversion function from "unknown" to text
Date
Msg-id 65937bea0901060943w52c5473ucee1a90f36842d4c@mail.gmail.com
Whole thread Raw
In response to Re: [HACKERS] ERROR: failed to find conversion function from "unknown" to text  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: [HACKERS] ERROR: failed to find conversion function from "unknown" to text  (Martijn van Oosterhout <kleptog@svana.org>)
List pgsql-general
On Tue, Jan 6, 2009 at 7:18 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
"Gurjeet Singh" <singh.gurjeet@gmail.com> writes:
>> This is a horrendously bad idea; it will bite your *ss sooner or later,
>> probably sooner.

> Can you please let us know how this would be problematic?

The point is that it's going to have unknown, untested effects on the
default coercion rules, possibly leading to silent changes in the
behavior of queries that used to work.  If you'd rather retest every one
of your other queries than fix this one, then go ahead.


Changing the query is an option not given to us. It is being migrated from a BigDB.

I was working on these solutions assuming that these are workarounds to a bug. But from your mails, it seems that it is an expected behaviour; is it?

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 '')".

Its not exactly a bug, but sure is a problem that we should try to resolve.

Thanks and best regards,
--
gurjeet[.singh]@EnterpriseDB.com
singh.gurjeet@{ gmail | hotmail | indiatimes | yahoo }.com

EnterpriseDB      http://www.enterprisedb.com

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