Solution : https://service.sap.com/sap/support/notes/707820 (SAP Service marketplace login required)
Key words : 
crm middleware links, suppressing idc4 links, report rsrldrel periodically, relevant link tables, note combines information, report rsrldrel, link tables, object links, idoc links, access links
Related Notes : 
       
| 908194 | Performance of RSRLDREL2 | 
| 907464 | Performance of RSRLDREL | 
| 790363 | Collective note for CDB Upgrade from CRM 3.X to CRM 4.0/5.0 | 
| 713173 | Update of the CRM Middleware reorganization SMO6_REORG | 
| 687653 | Index SRRELROLES~002 | 
| 574349 | IDoc: Avoiding IDC4 links | 
| 566765 | Deletion: Reducing read accesses to SRRELROLES | 
| 505608 | ALE: Reorganizing IDOCREL | 
| 493156 | Performance of BDoc message related object links | 
| 490297 | Processing-intensive SQL statement in the RSRLDREL report | 
| 441873 | Delete links: Reduce database accesses | 
| 384277 | Expensive SQL statement on table IDOCREL | 
| 313853 | Poor performance during link display |