Poor performance with Oracle Spatial when spatial query invoked remotely

Question

Is anyone aware of any problems with Oracle Spatial (10.2.0.4 with patches 6989483 and 7003151 on Red Hat Linux 4) which might explain why a spatial query (SDO_WITHIN_DISTANCE) would perform 20 times worse when it was invoked remotely from another computer (using SQLplus) vs. invoking the very same query from the database server itself (also using SQLplus)?
Does Oracle Spatial have any known problems with servers which use SAN disk storage? That is the primary difference between a server in which I see this poor performance and another server where the performance is fine.
Thank you in advance for any thoughts you might share.

Answer 1

OK, that's clearer.
Are you sure it is the SQL inside the procedure that is causing the problem? To check, try extracting the SQL from inside the procedure and run it in SQLPLUS with
set autotrace on
set timing on
SELECT ....If the plans and performance are the same then it may be something inside the procedure itself.
Have you profiled the procedure? Here is an example of how to do it:
Prompt Firstly, create PL/SQL profiler table
@$ORACLE_HOME/rdbms/admin/proftab.sql
Prompt Secondly, use the profiler to gather stats on execution characteristics
DECLARE
  l_run_num PLS_INTEGER := 1;
  l_max_num PLS_INTEGER := 1;
  v_geom    mdsys.sdo_geometry := mdsys.sdo_geometry(2002,null,null,sdo_elem_info_array(1,2,1),sdo_ordinate_array(0,0,45,45,90,0,135,45,180,0,180,-45,45,-45,0,0));
BEGIN
  dbms_output.put_line('Start Profiler Result = ' || DBMS_PROFILER.START_PROFILER(run_comment => 'PARALLEL PROFILE'));  -- The comment name can be anything: here it is related to the Parallel procedure I am testing.
  v_geom := Parallel(v_geom,10,0.05,1);  -- Put your procedure call here
  dbms_output.put_line('Stop Profiler Result = ' || DBMS_PROFILER.STOP_PROFILER );
END;
SHOW ERRORS
Prompt Finally, report activity
COLUMN runid FORMAT 99999
COLUMN run_comment FORMAT A40
SELECT runid || ',' || run_date || ',' || run_comment || ',' || run_total_time
  FROM plsql_profiler_runs
  ORDER BY runid;
COLUMN runid       FORMAT 99999
COLUMN unit_number FORMAT 99999
COLUMN unit_type   FORMAT A20
COLUMN unit_owner  FORMAT A20
COLUMN text        FORMAT A100
compute sum label 'Total_Time' of total_time on runid
break on runid skip 1
set linesize 200
SELECT u.runid || ',' ||
       u.unit_name,
       d.line#,
       d.total_occur,
       d.total_time,
       text
FROM   plsql_profiler_units u
       JOIN plsql_profiler_data d ON u.runid = d.runid
                                     AND
                                     u.unit_number = d.unit_number
       JOIN all_source als ON ( als.owner = 'CODESYS'
                               AND als.type = u.unit_type
                               AND als.name = u.unit_name
                            AND als.line = d.line# )
WHERE  u.runid = (SELECT max(runid) FROM plsql_profiler_runs)
ORDER BY d.total_time desc;Run the profiler in both environments and see if you can see where the slowdown exists.
regards
Simon