Re: Creating unique or "internal-use-only" column names (ColumnRef) - Mailing list pgsql-hackers

Andrew Dunstan <andrew@dunslane.net> writes:
> On 09/07/2015 09:28 AM, Alvaro Herrera wrote:
>> This seems pretty much the same as a junk attribute, if I understand you
>> correctly.  I suggest given a look at how those work.

> Is that actually documented anywhere much?

I don't think there's much besides a code comment here and there.
Grepping for functions that touch the "resjunk" field of TargetListEntries
should give you the lay of the land.
        regards, tom lane