Facing Merge Join Cartersian in the explain plan after adding gl periods

Question

Hi All
I have added gl periods table to the below query , checked the explain plan and it shows merge join cartesian. This query is taking long time to fetch the results.
Need help ASAP , Please let me know where i am going wrong . Any suggestions will be appreciated.
SELECT gljh.period_name, gljh.ledger_id, gljh.je_source,
glcc.segment2,
SUM ( NVL (gljl.accounted_dr, 0)
- NVL (gljl.accounted_cr, 0)
) total_amt,
gljh.currency_code
FROM gl_je_headers gljh,
gl_je_lines gljl,
gl_code_combinations glcc,
gl_periods gps
WHERE 1=1
AND gljh.period_name = gps.period_name
AND gljl.period_name = gps.period_name
AND gps.period_set_name = 'MCD_MONTH_'
AND gps.start_date >= :p_from_date
AND gps.start_date <= :p_to_date
AND gljh.ledger_id = :p_ledger_id
AND gljh.je_header_id = gljl.je_header_id
AND gljl.code_combination_id = glcc.code_combination_id
AND glcc.segment2 = '10007'--get_segment2_rec.flex_value
AND gljh.currency_code <> 'STAT'
GROUP BY gljh.je_source,
gljh.period_name,
glcc.segment2,
gljh.ledger_id,
gljh.currency_code
HAVING SUM ( NVL (gljl.accounted_dr, 0)
- NVL (gljl.accounted_cr, 0)
) <> 0;
Plan
SELECT STATEMENT ALL_ROWSCost: 73,146 Bytes: 2,266 Cardinality: 22                                              
     15 FILTER                                         
          14 HASH GROUP BY Cost: 73,146 Bytes: 2,266 Cardinality: 22                                    
               13 FILTER                               
                    12 NESTED LOOPS Cost: 73,145 Bytes: 61,079 Cardinality: 593                          
                         9 NESTED LOOPS Cost: 31,603 Bytes: 1,452,780 Cardinality: 20,754                     
                              6 MERGE JOIN CARTESIAN Cost: 2,108 Bytes: 394,181 Cardinality: 9,167                
                                   2 TABLE ACCESS BY INDEX ROWID TABLE GL.GL_PERIODS Cost: 4 Bytes: 31 Cardinality: 1           
                                        1 INDEX RANGE SCAN INDEX (UNIQUE) GL.GL_PERIODS_U2 Cost: 1 Cardinality: 64      
                                   5 BUFFER SORT Cost: 2,104 Bytes: 683,988 Cardinality: 56,999           
                                        4 TABLE ACCESS BY INDEX ROWID TABLE GL.GL_CODE_COMBINATIONS Cost: 2,104 Bytes: 683,988 Cardinality: 56,999      
                                             3 INDEX RANGE SCAN INDEX GL.GL_CODE_COMBINATIONS_N2 Cost: 155 Cardinality: 56,999
                              8 TABLE ACCESS BY INDEX ROWID TABLE GL.GL_JE_LINES Cost: 18 Bytes: 54 Cardinality: 2                
                                   7 INDEX RANGE SCAN INDEX GL.GL_JE_LINES_N1 Cost: 3 Cardinality: 37           
                         11 TABLE ACCESS BY INDEX ROWID TABLE GL.GL_JE_HEADERS Cost: 2 Bytes: 33 Cardinality: 1                     
                              10 INDEX UNIQUE SCAN INDEX (UNIQUE) GL.GL_JE_HEADERS_U1 Cost: 1 Cardinality: 1                
Thanks
Chandra

Answer 1

Lots of things come into play when you're tuning a query.
An (unformatted) execution plan isn't enough.
Tuning takes time and understanding how (a lot of) things work, there is no ASAP in the world of tuning.
Please post other important details, like your database version, optimizer settings, how/when are table statistics gathered etc.
So, read the following informative threads (and please take your time, this really is important stuff), and adust your thread as needed.
That way you'll have a bigger chance of getting help that makes sense...
Your DBA should/ought to be able to help you in this as well.
Re: HOW TO: Post a SQL statement tuning request - template posting
http://oracle-randolf.blogspot.com/2009/02/basic-sql-statement-performance.html