[11g] Première optimisation SQL

Salut

Je m'initie à l'optimisation SQL et voici la toute première requête qu'on me demande d'optimiser.

SQL Statement

Code:

1
2
3
4
5
6
SELECT                                                                                                            
  *                                                                                                               
FROM                                                                                                              
  "JKAP"                                                                                                          
WHERE                                                                                                             
  "MANDT"=:A0 AND "VBELN" BETWEEN :A1 AND :A2 AND "GUELTIGVON">=:A3

Execution Plan                                                                                                    
                                                                                                                  
Explain from gv$sql_plan: Address: 0700000111CA4DB8 Hash_value:  635054778 Child_number:  0 Instance_ID: 1        
Sql_id: 9319zshkxnapu  Parse Timestamp: 20131211   09:58:53                                                       
                                                                                                                  
ASH Samples: v$active_session_history                                                            
                                                                                                 

EVENT                                                     SAMPLES          PCT  
Total                                                       6 542          100 %
db file sequential read                                     6 436           98 %
Others                                                        106            2 %


SELECT STATEMENT ( Estimated Costs = 23 000 , Estimated #Rows = 0 ) (ID: 0; Samples: 57; 1%)     
                                                                                                 
    --  3 FILTER                                                                                  
    |     Filter Predicates                                                                       
    |                                                                                             
    | --  2 TABLE ACCESS BY INDEX ROWID JKAP (ID: 2; Samples: 6 326; 97%)                       
             ( Estim. Costs = 23 000 , Estim. #Rows = 1 041 )                                    
      |       Estim. CPU-Costs = 285 265 159 Estim. IO-Costs = 22 937                             
      |       Filter Predicates                                                                   
      |                                                                                           
      | --     1 INDEX RANGE SCAN JKAP~0 (ID: 3; Samples: 159; 2%)                               
                 ( Estim. Costs = 234 , Estim. #Rows = 37 485 )                                  
                 Search Columns: 2                                                               
                 Estim. CPU-Costs = 9 131 974 Estim. IO-Costs = 232                              
                 Access Predicates

J'ai la chance de pouvoir gérer tout le système : Base ORACLE 11.2.030, sur AIX 6.1.

Pouvez-vous me recommander un ou deux link sur le Tuning SQL Oracle 11 ?
Merci beaucoup.

Christophe.