Solution : https://service.sap.com/sap/support/notes/106047 (SAP Service marketplace login required)
Key words : 
mark customer-specific dbstatc entries, table-specific change threshold, solution call transaction db21, unsuitable access paths, standard system behavior, manually implemented entries, update check box, exception table dbstatc, table entries compared, achieve optimal statistics
Related Notes : 
       
| 1374807 | Freezing single kinds of statistics | 
| 1312060 | BW-BCT-CO-OM: COSP/COSS Extractor performance | 
| 972013 | Performance Blocked Documents Report: Database settings | 
| 932975 | Oracle statistics for RFC tables | 
| 902675 | MB51: Database hints to improve runtime / 4.70 | 
| 902157 | MB5B: Improving the runtime using database hints/4.70 | 
| 869006 | Composite SAP note: ORA-04031 | 
| 724545 | Adjusting the CBO statistics manually using DBMS_STATS | 
| 458872 | ORA-00001 with sapdba or BR tools | 
| 335415 | Creating and Maintaining Histograms | 
| 151847 | Index on table DRAW is not used optimally | 
| 131372 | CBO: Tuning of expensive SQL statements | 
| 128486 | DB21: Customizing the DBSTATC | 
| 122718 | CBO: Tables with special treatment | 
| 109034 | Collective note: SAPDBA - performance/CBO | 
| 93098 | CBO: Changes in upgrade to 4.0 |