i have four same tables in postgres and oracle.I'm using the postgres 7.1 version.
listed below
               
GROUPSMS=# select * from group_smu_trans ;
 sub_id |  con_phone   |                             message                              |
--------+--------------+------------------------------------------------------------------+---------
      2 | 919810058237 | hi checking                                                      | 2001-05-01
      2 | 919810299102 | hi checking                                                      | 2001-05-01
      2 | 919810058237 | hi checking                                                      | 2001-05-01
      2 | 919810299102 | hi checking                                                      | 2001-05-01
      2 | 919810058237 | hi checking                                                      | 2001-05-01
      2 | 919810299102 | hi checking                                                      | 2001-05-01
      2 | 9810125422   | Kindly Check . 						  | 2001-05-01
(7 rows)

GROUPSMS=# select * from subscriber_mast ;
 sub_id | sub_name  | sub_username |  sub_pwd  | sub_phone |    sub_add     | sub_type | plan
--------+-----------+--------------+-----------+-----------+----------------+----------+------
      2 | veeren    | veeren       | veeren    | 8976548   | kljhjkhdslkjhf | o        | c
     10 | textarea1 | textarea1    | textarea1 | textarea1 | textarea1      | o        | c
(2 rows)

GROUPSMS=# select * from sub_group_contact_lnk;
 sub_id | group_id | contact_id
--------+----------+------------
      2 |       18 |
      2 |       18 |         27
      2 |       21 |
      2 |       21 |         33
      2 |       21 |         37
(5 rows)

GROUPSMS=# select * from pre_sub_bal   ;
 sub_id | sub_total | sub_current | msg_rate
--------+-----------+-------------+----------
      3 |       350 |         200 |      125
      4 |       250 |         200 |       75
      7 |       500 |         500 |       75
      8 |       250 |         250 |       75
      1 |       250 |         125 |      125
      2 |       250 |      117.25 |      125
(6 rows)

create view mis_group_smu_trans
as
  select sub_id,count(message) as tot_message,count(con_phone) as con_phone  from
group_smu_trans
        group by sub_id;
GROUPSMS=# select * from  mis_group_smu_trans  ;
 sub_id | tot_message | con_phone
--------+-------------+-----------
      2 |           7 |         7
(1 row)

create view mis_sub_group_contact
as
  select sub_id,count(distinct group_id) as
group_id,count(distinct contact_id) as contact_id from
 sub_group_contact_lnk
        group by sub_id;
GROUPSMS=# select * from  mis_sub_group_contact;
 sub_id | group_id | contact_id
--------+----------+------------
      2 |        2 |          3
(1 row)

create view test1 as
select
a.sub_id,a.sub_name,c.tot_message,c.con_phone,d.sub_total,d.sub_current
        from
                subscriber_mast a,
                mis_group_smu_trans c,
                pre_sub_bal d
        where
                a.sub_id=c.sub_id and a.sub_id=d.sub_id;
GROUPSMS=# select * from test1;
 sub_id | sub_name | tot_message | con_phone | sub_total | sub_current
--------+----------+-------------+-----------+-----------+-------------
      2 | veeren   |           7 |         7 |       250 |      117.25
(1 row)

create view test2 as
select
a.sub_id,b.group_id,b.contact_id
        from
                subscriber_mast a,
                mis_sub_group_contact b
        where
                a.sub_id=b.sub_id;

GROUPSMS=# select * from test2;
 sub_id | group_id | contact_id
--------+----------+------------
      2 |        2 |          3
(1 row)


select a.*,b.* from test1 a ,test2 b
where b.sub_id=a.sub_id;

GROUPSMS-# where b.sub_id=a.sub_id;
 sub_id | sub_name | tot_message | con_phone | sub_total | sub_current | sub_id | group_id | contac
--------+----------+-------------+-----------+-----------+-------------+--------+----------+--------
      2 | veeren   |          35 |        35 |       250 |      117.25 |      2 |        2 |       3
(1 row)






       Now wht happen is in my final query of test1 and test2, "total_message" and "con_phone" both 
the columns output is changed by 5 times which is a random value.


   The same test case i have taken to the "oracle"  there i find the it is working absolutly fine.
Kindly handle this issue because one of major application at my customor end is running.


  

   Regards
    Shashi Bhushan Ahuja