Re: ERROR: FULL JOIN is only supported with merge-joinable - Mailing list pgsql-general

From Tom Lane
Subject Re: ERROR: FULL JOIN is only supported with merge-joinable
Date
Msg-id 9075.1142275758@sss.pgh.pa.us
Whole thread Raw
In response to Re: ERROR: FULL JOIN is only supported with merge-joinable  (Harco de Hilster <Harco.de.Hilster@ATConsultancy.nl>)
Responses Re: ERROR: FULL JOIN is only supported with merge-joinable  (Greg Stark <gsstark@mit.edu>)
List pgsql-general
Harco de Hilster <Harco.de.Hilster@ATConsultancy.nl> writes:
> What is the definition of a merge-joinable condition?

Equality on a sortable datatype.

> Can I create an type/operator that compares both records that is
> considered merge-joinable?

I think you could do something involving a time interval datatype that
considers "overlap" as equality and does something reasonable for
sorting non-overlapping intervals.  It'd take a bit of work ... nothing
particularly difficult, just tedious.  The "seg" datatype in contrib/
might serve as a prototype.

            regards, tom lane

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