Problem with inherited tables vs query planning

I have a query which runs a join between a table with multiple child tables
and a second table. The planner is doing a sequential scan of the children,
then doing the join on the result, despite having indices that are relevant.
If I do the join between any of the children and the second table, the index
is used. Note that the planner does well when it doesn't have to deal with
the join -- it handles the child tables (and their indices) fine normally.

I think the simple example below demonstrates the problem I'm having:

create table base (file integer, data integer);
create table child_0 () inherits (base);
create table child_1 () inherits (base);
create index child_0_file_index on child_0 using btree (file);
create index child_1_file_index on child_1 using btree (file);
create table other (file integer, stuff integer);
analyze;
<insert lots of data here>

testing=> explain SELECT * from base join other using (file) where stuff =
1;
                                 QUERY PLAN
----------------------------------------------------------------------------
 Hash Join  (cost=34.27..285.26 rows=597 width=12)
   Hash Cond: ("outer".file = "inner".file)
   ->  Append  (cost=0.00..185.34 rows=11934 width=8)
         ->  Seq Scan on base  (cost=0.00..29.40 rows=1940 width=8)
         ->  Seq Scan on child_0 base  (cost=0.00..77.98 rows=4998 width=8)
         ->  Seq Scan on child_1 base  (cost=0.00..77.96 rows=4996 width=8)
   ->  Hash  (cost=34.25..34.25 rows=10 width=8)
         ->  Seq Scan on other  (cost=0.00..34.25 rows=10 width=8)
               Filter: (stuff = 1)


testing=> explain SELECT * from child_1 join other using (file) where stuff
= 1;
                                       QUERY PLAN
----------------------------------------------------------------------------
------------
 Nested Loop  (cost=0.00..64.51 rows=10 width=12)
   ->  Seq Scan on other  (cost=0.00..34.25 rows=10 width=8)
         Filter: (stuff = 1)
   ->  Index Scan using child_1_file_index on child_1  (cost=0.00..3.01
rows=1 width=8)
         Index Cond: (child_1.file = "outer".file)


Is there a way I can reformulate the query to help the planner use the
indices? I can clearly write a plpgsql function to run the query over all
child tables separately, but was hoping to learn more.

I'm running:
PostgreSQL 8.1.4 on x86_64-redhat-linux-gnu, compiled by GCC gcc (GCC) 3.4.3
20041212 (Red Hat 3.4.3-9.EL4)

I also tried this on 8.1.9 and 8.2.4, same results.

Thanks,
Dave Golombek
Senior Software Engineer
Black Duck Software, Inc.
http://www.blackducksoftware.com