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Message-ID: <4C63AD83.3060602@gmail.com>
Date: Thu, 12 Aug 2010 10:14:59 +0200
From: Yeb Havinga <yebhavinga@gmail.com>
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To: Tom Lane <tgl@sss.pgh.pa.us>
CC: Mark Rostron <mrostron@ql2.com>,
	"pgsql-admin@postgresql.org" <pgsql-admin@postgresql.org>
Subject: Re: how do i query the type of an object?
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	<1823.1281577198@sss.pgh.pa.us>
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Tom Lane wrote:
> Mark Rostron <mrostron@ql2.com> writes:
>   
>> Is there some way to query the data-type of '<some value expression>'?
>>     
>
> There's a SQL-standard construct called IS OF, and a function called
> pg_typeof, but it's not real clear whether either of those would help
> you.
>   
I failed finding IS OF in the pg documentation, however, 
http://farrago.sourceforge.net/design/UserDefinedTypesAndRoutines.html 
had a reference to it.

postgres=# create table a(a) as select 1;
SELECT 1
postgres=# select * from a where a IS OF (integer);
 a
---
 1
(1 row)

While learning this somehow triggers the 'cool I just learned some new 
obscure SQL trick' feeling, I am not sure if it is really useful without 
CREATE TYPE foo UNDER bar.

regards,
Yeb Havinga