Re: What does "merge-joinable join conditions" mean ????

"Dean Gibson (DB Administrator)" <postgresql4@ultimeth.com> writes:
> SELECT count(*)  FROM "GenAppExtra" FULL JOIN  "GeoRestrict" ON callsign 
> ~ pattern  WHERE region_id = 4 OR geo_region = 4;

> If either of the "region_id = 4"  (a field in the right-hand table) or 
> "geo_region = 4" (a field in the left-hand table) are removed, the 
> SELECT functions (does not give an error message),

Really?  The FULL JOIN condition using ~ is the source of the failure,
and I'd be quite surprised if changing WHERE makes it work.
        regards, tom lane