Slow report generation

Question

Hi,
I have a report where its results depend on what option the user chooses in a selection list. The select list option alters the where clause in the query and displays new information. The problem is that it takes a ridiculously long amount of time to display results that have a larger amount of results (~100). Even with a table with 12 results there is a noticeable delay. The query includes a subquery as well as an order by and uses links to the database which is meant to make it act slower but I don't think such a thing would affect it so badly with 100 results? By slow display I mean around 5 minutes of loading. Meanwhile a query (not in the report) without the where statement doesn't take very long. The code is as follows:
select rpad(svc_app_name,8) project,rpad(loc_name,12)location,
rpad(svc_name,10)service,svs_date size_date,
round((svs_used_sz/1024)) used_size_MB
from hkadm.srvc@HKADM2_DBAAPEX.TNTEWW.COM, hkadm.svcsize@HKADM2_DBAAPEX.TNTEWW.COM, hkadm.host@HKADM2_DBAAPEX.TNTEWW.COM, hkadm.loc@HKADM2_DBAAPEX.TNTEWW.COM
where
   svc_name = svs_svc_name
   and svs_date = (select max(svs_date) from hkadm.svcsize@HKADM2_DBAAPEX.TNTEWW.COM a
                      where a.svs_hst_ip = svcsize.svs_hst_ip
                        and a.svs_svc_name = svcsize.svs_svc_name)
and svc_app_name = :P5_Link
  and svc_hst_ip = hst_ip
  and hst_loc_code = loc_code
order by 1,2,3,4My select list has submit on click and and there's a branch to the same page on submit. Any help appreciated.
Mike

Answer 1

You should create a view at your remote server like this:
CREATE OR REPLACE VIEW test_view
AS
   SELECT   RPAD (svc_app_name, 8) project, RPAD (loc_name, 12) LOCATION,
            RPAD (svc_name, 10) service, svs_date size_date,
            ROUND ((svs_used_sz / 1024)) used_size_mb,
            svc_app_name
       FROM hkadm.srvc, hkadm.svcsize, hkadm.HOST, hkadm.loc
      WHERE svc_name = svs_svc_name
        AND svs_date =
               (SELECT MAX (svs_date)
                  FROM hkadm.svcsize a
                 WHERE a.svs_hst_ip = svcsize.svs_hst_ip
                   AND a.svs_svc_name = svcsize.svs_svc_name)
        AND svc_hst_ip = hst_ip
        AND hst_loc_code = loc_code
   ORDER BY 1, 2, 3, 4and query it like this:
SELECT project, LOCATION, service, size_date, used_size_mb
  FROM test_view@hkadm2_dbaapex.tnteww.com
WHERE svc_app_name = :p5_listDenes Kubicek
http://deneskubicek.blogspot.com/
http://www.opal-consulting.de/training
http://apex.oracle.com/pls/otn/f?p=31517:1
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