Query Against a dblink View Takes Too Long to Return

 PostgreSQL Version: 7.2.1 
 OS : Red Hat 7.3 with Kernel 2.4.18-5 and SGI_XFS 

 Currently we have a view defined: 
 CREATE VIEW db1_info_view AS 
               SELECT CAST(dblink_tok(t1.dblink_db1_info,0) AS MACADDR)   AS id1, 
                                  CAST(dblink_tok(t1.dblink_db1_info,1) AS MACADDR)   AS id2, 
                            textToBoolean(dblink_tok(t1.dblink_db1_info,2))              AS valid, 
                                  CAST(dblink_tok(t1.dblink_db1_info,3) AS TIMESTAMPTZ) AS modify_time 
               FROM (SELECT dblink('hostaddr=127.0.0.1 port=5432 dbname=db1 user=postgres', 
                          'SELECT id1, id2, valid, modify_time FROM db1_info') AS dblink_db1_info) AS t1; 

 Periodically we update information in the second database based upon the modify time from this view. This is the query that is run from a stored procedure. I've separated it out of the stored procedure because running it by hand in psql has the same problem. 

 SELECT v.id1, v.id2, v.valid, v.modify_time 
 FROM db1_info_view v LEFT OUTER JOIN db2_info d ON (v.id1 = d.id1 AND v.id2 = d.id2) WHERE v.modify_time >= d.modify_time; 

 Until recently this has worked perfectly.  We started increasing the number of records in these tables and now we're running into the problem where the SELECT statement does not return. I'm not talking about a lot of records. Both tables in the query only have about 9,000 records each. 

 I can do a SELECT COUNT(*) or SELECT * on the view and it comes back instantly. I can SELECT * and ORDER BY modify_time and it comes back instantly. As soon as I try to join the view to another table the query takes 10 to 20 minutes to come back. 

 NOTICE:  QUERY PLAN: 

 Nested Loop  (cost=0.00..466.51 rows=1 width=24) (actual time=226.39..1018072.99 rows=9353 loops=1) 
   ->  Subquery Scan t1  (cost=0.00..0.01 rows=1 width=0) (actual time=225.99..345.86 rows=9353 loops=1) 
         ->  Result  (cost=0.00..0.01 rows=1 width=0) (actual time=225.98..303.29 rows=9353 loops=1) 
   ->  Seq Scan on allowed_station_view av  (cost=0.00..162.53 rows=9353 width=20) (actual time=0.01..31.77 rows=9353 loops=9353) 
 Total runtime: 1018092.69 msec 

 EXPLAIN 

 If I create a temporary table by selecting everything from the view and then do the join it comes back instantly. 

 NOTICE:  QUERY PLAN: 

 Merge Join  (cost=69.83..526.68 rows=1000 width=40) (actual time=109.03..247.78 rows=9353 loops=1) 
   ->  Index Scan using allowed_station_view_pkey on allowed_station_view av  (cost=0.00..426.88 rows=9353 width=20) (actual time=0.03..41.93 rows=9353 loops=1) 
   ->  Sort  (cost=69.83..69.83 rows=1000 width=20) (actual time=108.95..120.77 rows=9353 loops=1) 
         ->  Seq Scan on allowed_station_view_test al  (cost=0.00..20.00 rows=1000 width=20) (actual time=0.07..26.67 rows=9353 loops=1) 
 Total runtime: 261.97 msec 

 EXPLAIN 

 Am I misusing dblink? 

 Dawn Hollingsworth 
 AirDefense, Inc.