From: Tom Lane <tgl@sss.pgh.pa.us>
To: arthur.mcgibbon@gmail.com
cc: pgsql-bugs@lists.postgresql.org
Subject: Re: BUG #17052: Incorrect params inferred on PREPARE (part 2)
In-reply-to: <17052-0bb053c08bb80fb6@postgresql.org>
References: <17052-0bb053c08bb80fb6@postgresql.org>
Comments: In-reply-to PG Bug reporting form <noreply@postgresql.org>
	message dated "Tue, 08 Jun 2021 11:27:51 -0000"
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-ID: <1119503.1623170371.1@sss.pgh.pa.us>
Date: Tue, 08 Jun 2021 12:39:31 -0400
Message-ID: <1119504.1623170371@sss.pgh.pa.us>
Archived-At: 
 <https://www.postgresql.org/message-id/1119504.1623170371%40sss.pgh.pa.us>
Precedence: bulk

PG Bug reporting form <noreply@postgresql.org> writes:
>   SET timestampCol = $1 + interval '1 minute';
> ...results in an error...
> ERROR:  column "timestampcol" is of type timestamp without time zone but
> expression is of type interval
> LINE 4:   set timestampCol = $1 + interval '1 minute';
>                              ^

As in your other report, the context in which the parameter type is
guessed is just the immediate context of the plus-operator expression.
The relevant rule there is "guess that an unknown input is of the same
type as the other input", so we resolve the operator as interval + interval.

			regards, tom lane