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

On 2006-01-15 15:21, Tom Lane wrote:
> Really?  The FULL JOIN condition using ~ is the source of the failure, and I'd be quite surprised if changing WHERE
makesit work.
 
>   

Works fine:

EXPLAIN SELECT count(*)  FROM "Extra" FULL JOIN  "GeoRestrict" ON
callsign ~ pattern  WHERE geo_region =
4;                                  QUERY
PLAN
---------------------------------------------------------------------------------
Aggregate  (cost=1934.02..1934.02 rows=1 width=0)  ->  Nested Loop Left Join  (cost=1.18..1926.66 rows=2943 width=0)
   Join Filter: ("outer".callsign ~ ("inner".pattern)::text)        ->  Seq Scan on "Extra"  (cost=0.00..866.00
rows=2943width=10)              Filter: (geo_region = 4)        ->  Materialize  (cost=1.18..1.34 rows=16 width=7)
       ->  Seq Scan on "GeoRestrict"  (cost=0.00..1.16 rows=16
 
width=7)

Note that this used to be just a LEFT JOIN (which also worked), but
today I wanted to include rows from "GeoRestrict" that had nulls for the
left-hand-side of the query, so I changed the LEFT JOIN to a FULL JOIN
(that worked), and then attempted to add a condition to restrict which
rows were included from "GeoRestrict", and that gave the error.

-- Dean