Bulk Collect taking more time. Please suggest .

Question

I am working on oracle 11g
I have one normal insert proc
CREATE OR REPLACE PROCEDURE test2
AS
     BEGIN
     INSERT INTO first_table
     (citiversion, financialcollectionid,
     dataitemid, dataitemvalue,
     unittypeid, financialinstanceid,
     VERSION, providerid, user_comment,
     userid, insert_timestamp,
     latestflag, finalflag, filename,
     final_ytdltm_flag, nmflag , partition_key
     SELECT citiversion, financialcollectionid,
     dataitemid, dataitemvalue, unittypeid,
     new_fi, VERSION, providerid,
     user_comment, userid,
     insert_timestamp, latestflag,
     finalflag, filename, '', nmflag,1
     FROM secon_table
     WHERE financialinstanceid = 1
AND changeflag = 'A'
AND processed_flg = 'N';
     END test2;
To impove performance i have normal insert into convert it to bulk collect :
CREATE OR REPLACE PROCEDURE test
AS
BEGIN
     DECLARE
     CURSOR get_cat_fin_collection_data(n_instanceid NUMBER) IS
     SELECT citiversion,
     financialcollectionid,
     dataitemid,
     dataitemvalue,
     unittypeid,
     new_fi,
     VERSION,
     providerid,
     user_comment,
     userid,
     insert_timestamp,
     latestflag,
     finalflag,
     filename,
     nmflag,
               1
     FROM secon_table
     WHERE financialinstanceid = n_instanceid
AND changeflag = 'A'
AND processed_flg = 'N';
     TYPE data_array IS TABLE OF get_cat_fin_collection_data%ROWTYPE;
     l_data data_array;
     BEGIN
     OPEN get_cat_fin_collection_data(1);
     LOOP
     FETCH get_cat_fin_collection_data BULK COLLECT
     INTO l_data limit 100;
     FORALL i IN 1 .. l_data.COUNT
     INSERT INTO first_table VALUES l_data (i);
EXIT WHEN l_data.count =0;
     END LOOP;
     CLOSE get_cat_fin_collection_data;
     END;
     END test;
But bulk collect is taking more time.
below is the timings
SQL> set timing on
SQL> exec test
PL/SQL procedure successfully completed
Executed in 16.703 seconds
SQL> exec test2
PL/SQL procedure successfully completed
Executed in 9.406 seconds
SQL> rollback;
Rollback complete
Executed in 2.75 seconds
SQL> exec test
PL/SQL procedure successfully completed
Executed in 16.266 seconds
SQL> rollback;
Rollback complete
Executed in 2.812 seconds
Normal insert :- 9.4 second
Bulk insert:- 16.266 seconds
I am processing 1 lakh rows.
Can you please tell me the reason why bulk collect is taking more time. ? According to my knowledge it should take less time.
Please suggect do i need to check any parameter?
Please help.
Edited by: 976747 on Feb 4, 2013 1:12 AM

Answer 1

>
Can you please tell me the reason why bulk collect is taking more time. ? According to my knowledge it should take less time.
Please suggect do i need to check any parameter?In that case, your knowledge is flawed.
Pure SQL is almost always faster than PL/SQL.
If your Insert into Select is executing slow, then it is probably because the Select statement is taking long to execute. How many rows are being Selected and Inserted from your query?
You might also consider tuning the Select statement. For more information on Posting a Tuning request, read {message:id=3292438} and post the relevant information.