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From: Tom Lane <tgl@sss.pgh.pa.us>
To: rekgrpth@gmail.com
cc: pgsql-bugs@lists.postgresql.org
Subject: Re: BUG #17147: Why concat_ws and concat is not immutable?
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References: <17147-11e30c950a4faae8@postgresql.org>
Comments: In-reply-to PG Bug reporting form <noreply@postgresql.org>
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PG Bug reporting form <noreply@postgresql.org> writes:
> Why concat_ws and concat is not immutable?

Those invoke datatype-specific output functions, which aren't guaranteed
to be immutable.  Maybe ideally they would be, but we have too much
historical baggage --- for example, timestamp_out has always depended
on DateStyle.

			regards, tom lane