Performance issue with a Custom view

Question

Hi ,
I am pretty new to performance tuning and facing a performance issue with a custom view.
Execution time for view query is good but as soon as I append a where caluse to view query ,the execution time increases.
Below is the view query:
CREATE OR REPLACE XXX_INFO_VIEW AS
SELECT csb.system_id license_id,
cst.name license_number ,
csb.system_type_code license_type ,
csb.attribute3 lac , -- license authorization code
csb.attribute6 lat , -- license admin token
csb.attribute12 ols_reg, -- OLS Registration allowed flag
l.attribute4 license_biz_type ,
NVL (( SELECT 'Y' l_supp_flag
FROM csi_item_instances cii,
okc_k_lines_b a,
okc_k_items c
WHERE c.cle_id = a.id
AND a.lse_id = 9
AND c.jtot_object1_code = 'OKX_CUSTPROD'
AND c.object1_id1 = cii.instance_id||''
AND cii.instance_status_id IN (3, 510)
AND cii.system_id = csb.system_id
AND a.sts_code IN ('SIGNED', 'ACTIVE')
AND NVL (a.date_terminated, a.end_date) > SYSDATE
AND ROWNUM < 2), 'N') active_supp_flag,
hp.party_name "Customer_Name" , -- Customer Name
hca.attribute12 FGE_FLAG,
(SELECT /*+INDEX (oklt OKC_K_LINES_TL_U1) */
nvl(max((decode(name, 'eSupport','2','Enterprise','1','Standard','1','TERM RTU','0','TERM RTS','0','Notfound'))),0) covName --TERM RTU and TERM RTS added as per Vijaya's suggestion APR302013
FROM OKC_K_LINES_B oklb1,
OKC_K_LINES_TL oklt,
OKC_K_LINES_B oklb2,
OKC_K_ITEMS oki,
CSI_item_instances cii
WHERE
OKI.JTOT_OBJECT1_CODE = 'OKX_CUSTPROD'
AND oklb1.id=oklt.id
AND OKI.OBJECT1_ID1 =cii.instance_id||''
AND Oklb1.lse_id=2
AND oklb1.dnz_chr_id=oklb2.dnz_chr_id
AND oklb2.lse_id=9
AND oki.CLE_ID=oklb2.id
AND cii.system_id=csb.system_id
AND oklt.LANGUAGE=USERENV ('LANG')) COVERAGE_TYPE
FROM csi_systems_b csb ,
csi_systems_tl cst ,
hz_cust_accounts hca,
hz_parties hp,
fnd_lookup_values l
WHERE csb.system_type_code = l.lookup_code (+)
AND csb.system_id = cst.system_id
AND hca.cust_account_id =csb.customer_id
AND hca.party_id= hp.party_id
AND cst.language = USERENV ('LANG')
AND l.lookup_type (+) = 'CSI_SYSTEM_TYPE'
AND l.language (+) = USERENV ('LANG')
AND NVL (csb.end_date_active, SYSDATE+1) > SYSDATE)
I have forced an index to avoid Full table scan on OKC_K_LINES_TL and suppressed an index on CSI_item_instances.instance id to make the view query fast.
So when i do select * from XXX_INFO_VIEWit executes in a decent time,But when I try to do
select * from XXX_INFO_VIEW where active_supp_flag='Y' and coverage_type='1'
it takes lot of time.
Execution plan is same for both queries in terms of cost but with WHERE clause Number of bytes increases.
Below are the execution plans:
View query:
SELECT STATEMENT ALL_ROWS Cost: 7,212 Bytes: 536,237 Cardinality: 3,211                                         
     10 COUNT STOPKEY                                    
          9 NESTED LOOPS                               
               7 NESTED LOOPS Cost: 1,085 Bytes: 101 Cardinality: 1                          
                    5 NESTED LOOPS Cost: 487 Bytes: 17,043 Cardinality: 299                     
                         2 TABLE ACCESS BY INDEX ROWID TABLE CSI.CSI_ITEM_INSTANCES Cost: 22 Bytes: 2,325 Cardinality: 155                
                              1 INDEX RANGE SCAN INDEX CSI.CSI_ITEM_INSTANCES_N07 Cost: 3 Cardinality: 315           
                         4 TABLE ACCESS BY INDEX ROWID TABLE OKC.OKC_K_ITEMS Cost: 3 Bytes: 84 Cardinality: 2                
                              3 INDEX RANGE SCAN INDEX OKC.OKC_K_ITEMS_N2 Cost: 2 Cardinality: 2           
                    6 INDEX UNIQUE SCAN INDEX (UNIQUE) OKC.OKC_K_LINES_B_U1 Cost: 1 Cardinality: 1                     
               8 TABLE ACCESS BY INDEX ROWID TABLE OKC.OKC_K_LINES_B Cost: 2 Bytes: 44 Cardinality: 1                          
     12 TABLE ACCESS BY INDEX ROWID TABLE AR.HZ_CUST_ACCOUNTS Cost: 2 Bytes: 7 Cardinality: 1                                    
          11 INDEX UNIQUE SCAN INDEX (UNIQUE) AR.HZ_CUST_ACCOUNTS_U1 Cost: 1 Cardinality: 1                               
     28 SORT AGGREGATE Bytes: 169 Cardinality: 1                                    
          27 NESTED LOOPS                               
               25 NESTED LOOPS Cost: 16,549 Bytes: 974,792 Cardinality: 5,768                          
                    23 NESTED LOOPS Cost: 5,070 Bytes: 811,737 Cardinality: 5,757                     
                         20 NESTED LOOPS Cost: 2,180 Bytes: 56,066 Cardinality: 578                
                              17 NESTED LOOPS Cost: 967 Bytes: 32,118 Cardinality: 606           
                                   14 TABLE ACCESS BY INDEX ROWID TABLE CSI.CSI_ITEM_INSTANCES Cost: 22 Bytes: 3,465 Cardinality: 315      
                                        13 INDEX RANGE SCAN INDEX CSI.CSI_ITEM_INSTANCES_N07 Cost: 3 Cardinality: 315
                                   16 TABLE ACCESS BY INDEX ROWID TABLE OKC.OKC_K_ITEMS Cost: 3 Bytes: 84 Cardinality: 2      
                                        15 INDEX RANGE SCAN INDEX OKC.OKC_K_ITEMS_N2 Cost: 2 Cardinality: 2
                              19 TABLE ACCESS BY INDEX ROWID TABLE OKC.OKC_K_LINES_B Cost: 2 Bytes: 44 Cardinality: 1           
                                   18 INDEX UNIQUE SCAN INDEX (UNIQUE) OKC.OKC_K_LINES_B_U1 Cost: 1 Cardinality: 1      
                         22 TABLE ACCESS BY INDEX ROWID TABLE OKC.OKC_K_LINES_B Cost: 5 Bytes: 440 Cardinality: 10                
                              21 INDEX RANGE SCAN INDEX OKC.OKC_K_LINES_B_N2 Cost: 2 Cardinality: 9           
                    24 INDEX UNIQUE SCAN INDEX (UNIQUE) OKC.OKC_K_LINES_TL_U1 Cost: 1 Cardinality: 1                     
               26 TABLE ACCESS BY INDEX ROWID TABLE OKC.OKC_K_LINES_TL Cost: 2 Bytes: 28 Cardinality: 1                          
     43 HASH JOIN Cost: 7,212 Bytes: 536,237 Cardinality: 3,211                                    
          41 NESTED LOOPS                               
               39 NESTED LOOPS Cost: 7,070 Bytes: 485,792 Cardinality: 3,196                          
                    37 HASH JOIN Cost: 676 Bytes: 341,972 Cardinality: 3,196                     
                         32 HASH JOIN RIGHT OUTER Cost: 488 Bytes: 310,012 Cardinality: 3,196                
                              30 TABLE ACCESS BY INDEX ROWID TABLE APPLSYS.FND_LOOKUP_VALUES Cost: 7 Bytes: 544 Cardinality: 17           
                                   29 INDEX RANGE SCAN INDEX (UNIQUE) APPLSYS.FND_LOOKUP_VALUES_U1 Cost: 3 Cardinality: 17      
                              31 TABLE ACCESS FULL TABLE CSI.CSI_SYSTEMS_B Cost: 481 Bytes: 207,740 Cardinality: 3,196           
                         36 VIEW VIEW AR.index$_join$_013 Cost: 187 Bytes: 408,870 Cardinality: 40,887                
                              35 HASH JOIN           
                                   33 INDEX FAST FULL SCAN INDEX (UNIQUE) AR.HZ_CUST_ACCOUNTS_U1 Cost: 112 Bytes: 408,870 Cardinality: 40,887      
                                   34 INDEX FAST FULL SCAN INDEX AR.HZ_CUST_ACCOUNTS_N2 Cost: 122 Bytes: 408,870 Cardinality: 40,887      
                    38 INDEX UNIQUE SCAN INDEX (UNIQUE) AR.HZ_PARTIES_U1 Cost: 1 Cardinality: 1                     
               40 TABLE ACCESS BY INDEX ROWID TABLE AR.HZ_PARTIES Cost: 2 Bytes: 45 Cardinality: 1                          
          42 TABLE ACCESS FULL TABLE CSI.CSI_SYSTEMS_TL Cost: 142 Bytes: 958,770 Cardinality: 63,918           
Execution plan for view query with WHERE clause:
SELECT STATEMENT ALL_ROWS Cost: 7,212 Bytes: 2,462,837 Cardinality: 3,211                                         
     10 COUNT STOPKEY                                    
          9 NESTED LOOPS                               
               7 NESTED LOOPS Cost: 1,085 Bytes: 101 Cardinality: 1                          
                    5 NESTED LOOPS Cost: 487 Bytes: 17,043 Cardinality: 299                     
                         2 TABLE ACCESS BY INDEX ROWID TABLE CSI.CSI_ITEM_INSTANCES Cost: 22 Bytes: 2,325 Cardinality: 155                
                              1 INDEX RANGE SCAN INDEX CSI.CSI_ITEM_INSTANCES_N07 Cost: 3 Cardinality: 315           
                         4 TABLE ACCESS BY INDEX ROWID TABLE OKC.OKC_K_ITEMS Cost: 3 Bytes: 84 Cardinality: 2                
                              3 INDEX RANGE SCAN INDEX OKC.OKC_K_ITEMS_N2 Cost: 2 Cardinality: 2           
                    6 INDEX UNIQUE SCAN INDEX (UNIQUE) OKC.OKC_K_LINES_B_U1 Cost: 1 Cardinality: 1                     
               8 TABLE ACCESS BY INDEX ROWID TABLE OKC.OKC_K_LINES_B Cost: 2 Bytes: 44 Cardinality: 1                          
     12 TABLE ACCESS BY INDEX ROWID TABLE AR.HZ_CUST_ACCOUNTS Cost: 2 Bytes: 7 Cardinality: 1                                    
          11 INDEX UNIQUE SCAN INDEX (UNIQUE) AR.HZ_CUST_ACCOUNTS_U1 Cost: 1 Cardinality: 1                               
     28 SORT AGGREGATE Bytes: 169 Cardinality: 1                                    
          27 NESTED LOOPS                               
               25 NESTED LOOPS Cost: 16,549 Bytes: 974,792 Cardinality: 5,768                          
                    23 NESTED LOOPS Cost: 5,070 Bytes: 811,737 Cardinality: 5,757                     
                         20 NESTED LOOPS Cost: 2,180 Bytes: 56,066 Cardinality: 578                
                              17 NESTED LOOPS Cost: 967 Bytes: 32,118 Cardinality: 606           
                                   14 TABLE ACCESS BY INDEX ROWID TABLE CSI.CSI_ITEM_INSTANCES Cost: 22 Bytes: 3,465 Cardinality: 315      
                                        13 INDEX RANGE SCAN INDEX CSI.CSI_ITEM_INSTANCES_N07 Cost: 3 Cardinality: 315
                                   16 TABLE ACCESS BY INDEX ROWID TABLE OKC.OKC_K_ITEMS Cost: 3 Bytes: 84 Cardinality: 2      
                                        15 INDEX RANGE SCAN INDEX OKC.OKC_K_ITEMS_N2 Cost: 2 Cardinality: 2
                              19 TABLE ACCESS BY INDEX ROWID TABLE OKC.OKC_K_LINES_B Cost: 2 Bytes: 44 Cardinality: 1           
                                   18 INDEX UNIQUE SCAN INDEX (UNIQUE) OKC.OKC_K_LINES_B_U1 Cost: 1 Cardinality: 1      
                         22 TABLE ACCESS BY INDEX ROWID TABLE OKC.OKC_K_LINES_B Cost: 5 Bytes: 440 Cardinality: 10                
                              21 INDEX RANGE SCAN INDEX OKC.OKC_K_LINES_B_N2 Cost: 2 Cardinality: 9           
                    24 INDEX UNIQUE SCAN INDEX (UNIQUE) OKC.OKC_K_LINES_TL_U1 Cost: 1 Cardinality: 1                     
               26 TABLE ACCESS BY INDEX ROWID TABLE OKC.OKC_K_LINES_TL Cost: 2 Bytes: 28 Cardinality: 1                          
     44 VIEW VIEW APPS.WRS_LICENSE_INFO_V Cost: 7,212 Bytes: 2,462,837 Cardinality: 3,211                                    
          43 HASH JOIN Cost: 7,212 Bytes: 536,237 Cardinality: 3,211                               
               41 NESTED LOOPS                          
                    39 NESTED LOOPS Cost: 7,070 Bytes: 485,792 Cardinality: 3,196                     
                         37 HASH JOIN Cost: 676 Bytes: 341,972 Cardinality: 3,196                
                              32 HASH JOIN RIGHT OUTER Cost: 488 Bytes: 310,012 Cardinality: 3,196           
                                   30 TABLE ACCESS BY INDEX ROWID TABLE APPLSYS.FND_LOOKUP_VALUES Cost: 7 Bytes: 544 Cardinality: 17      
                                        29 INDEX RANGE SCAN INDEX (UNIQUE) APPLSYS.FND_LOOKUP_VALUES_U1 Cost: 3 Cardinality: 17
                                   31 TABLE ACCESS FULL TABLE CSI.CSI_SYSTEMS_B Cost: 481 Bytes: 207,740 Cardinality: 3,196      
                              36 VIEW VIEW AR.index$_join$_013 Cost: 187 Bytes: 408,870 Cardinality: 40,887           
                                   35 HASH JOIN      
                                        33 INDEX FAST FULL SCAN INDEX (UNIQUE) AR.HZ_CUST_ACCOUNTS_U1 Cost: 112 Bytes: 408,870 Cardinality: 40,887
                                        34 INDEX FAST FULL SCAN INDEX AR.HZ_CUST_ACCOUNTS_N2 Cost: 122 Bytes: 408,870 Cardinality: 40,887
                         38 INDEX UNIQUE SCAN INDEX (UNIQUE) AR.HZ_PARTIES_U1 Cost: 1 Cardinality: 1                
                    40 TABLE ACCESS BY INDEX ROWID TABLE AR.HZ_PARTIES Cost: 2 Bytes: 45 Cardinality: 1                     
               42 TABLE ACCESS FULL TABLE CSI.CSI_SYSTEMS_TL Cost: 142 Bytes: 958,770 Cardinality: 63,918

Answer 1

Hi,
You should always try using primary index fields, if not possible then secondary index fields.
Even if you cannot do anything from either of the two then try this,
Use Less distinct fields on the top.
In your case , you can use bukrs ,gjahr ,werks on the top in the where condition..then followed by less distinct values..
Even when you use secondary index if you have 4 fields in your sec index and you are using only two fields from the top then the index is useful only upto that two fields provided they are in sequence.