performance issue

[Steven varga <varga(at)yorku(dot)ca>]

hi,

having about 10^6 records in a table indexed on names (http://www.upcdatabase.com)
and doing a query from psql I get response time in millisec order on the 
other hand when executing the same query through JDBC it hangs about 80 
seconds.
This is about 10^5 decrease in speed.

After profiling the JDBC driver simply waits for data 
PGStream.ReceiveChar() spending enough time to do a sequencial scan on all 
10^6 records.

 Can anyone give a suggestion why is this lag?



PSQL:

test=# EXPLAIN ANALYZE SELECT count(*) from upc  where name like 'Aba%';
QUERY PLAN
 Aggregate  (cost=14897.01..14897.02 rows=1 width=0) (actual 
time=0.380..0.381 rows=1 loops=1)
   ->  Bitmap Heap Scan on upc (cost=57.67..14885.47 rows=4612 
width=0) (actual time=0.216..0.326 rows=13 loops=1)
         Filter: ((name)::text ~~ 'Aba%'::text)
         ->  Bitmap Index Scan on upc_name  (cost=0.00..57.67 
rows=4612 width=0) (actual time=0.155..0.155 rows=13 loops=1)
               Index Cond: (((name)::text >= 'Aba'::character varying) AND 
((name)::text < 'Abb'::character varying))
 Total runtime: 0.670 ms
(6 rows)


JDBC:

 PreparedStatement count =
        connection.prepareStatement("SELECT count(*) FROM
	upc WHERE name like upper(?)||'%' ");

 count.setString(1,"Aba");
 ResultSet  rs = count.executeQuery(); //<== this takes about 82 seconds 
to execute


psql (PostgreSQL) 8.1.5
postgresql-jdbc-8.3-603