Query tuning for query using connect by prior

Question

I have written following query to fetch the data. The query is written in this format because there are multiple rows, which make one recrd and we need to bring that record into one row.
For one CAT(commented here), this query takes around 4 minutes and fetches 6900 records but when it runs for 3 CAT, it takes 17 mins.
I want to tune this as this has to run for 350 CAT values.
It is doing FTS on the main table. I tried to use different hints like PARALLEL, APPEND (in insert) but nothing worked.
The cost of the query is 51.
Any help/suggestions will be appreciated.
SELECT DISTINCT MIN(SEQ) SEQ,
PT, APP, IT, LR, QT,CD, M_A_FLAG,
STRAGG(REM) REM, -- aggregates the data from different columns to one which is parent
CAT
FROM (WITH R AS (SELECT CAT, SEQ, PT, M_A_FLAG, IT, LR,QT,CD, REM, APP
FROM table1
WHERE REC = '36' AND M_A_FLAG = '1'
--AND CAT = '11113')
SELECT CAT, SEQ,
CONNECT_BY_ROOT PT AS PT,
CONNECT_BY_ROOT APP AS APPL,
M_A_FLAG,
CONNECT_BY_ROOT IT AS IT,
CONNECT_BY_ROOT LR AS LR,
CONNECT_BY_ROOT QT AS QT,
CONNECT_BY_ROOT CD AS CD,
REM
FROM R A
START WITH PT IS NOT NULL
CONNECT BY PRIOR SEQ + 1 = SEQ
AND PRIOR CAT = CAT
AND PT IS NULL)
GROUP BY PT, APP, IT,LR, QT, CD, M_A_FLAG, CAT
ORDER BY SEQ;
Thanks.
Edited by: user2544469 on Feb 11, 2011 1:12 AM

Answer 1

The following threads detail the approach and information required.
Please gather relevant info and post back.
How to post a SQL tuning request - HOW TO: Post a SQL statement tuning request - template posting
When your query takes too long - When your query takes too long ...