Solution : https://service.sap.com/sap/support/notes/790099 (SAP Service marketplace login required)
Key words : 
online text repository                                     buffer              - abap/buffersize              program buffer size, single record table buffer                - rsdb/obj/buffersize           size, export/import buffer               - rsdb/ntab/ftabsize            size, field description buffer               - rsdb/ntab/irbdsize            size, generic key table buffer               - rtbb/buffer_length            size, initial record buffer                - rsdb/esm/buffersize_kb        size, unexpected memory consumption figures making insufficient recommendations, - install/codepage/appl_server- abap/unicode_checkall, cua buffer                - zcsa/table_buffer_area        size, - rsdb/cua/buffersize           size
Related Notes : 
       
| 1345121 | Profile Parameters which should not be set in Unicode | 
| 1319517 | Unicode Collection Note | 
| 1139642 | Hardware Requirements in Unicode Systems | 
| 835474 | More than 32 GB extended memory | 
| 789477 | Large extended memory on AIX (64-bit) as of Kernel 6.20 | 
| 551344 | Unicode Conversion Documentation | 
| 445533 | Lots of extended memory on AIX (64 bit) | 
| 425207 | SAP memory management, current parameter ranges | 
| 326949 | Shared Memory Management z/OS Application Server | 
| 153641 | Swap space requirement for R/3 64-bit kernel | 
| 139326 | AS/400: Memory Management in Release 4.6x | 
| 135503 | CCMS monitor architecture: Meaning of profile parameters | 
| 103747 | Performance: Parameter recommendations as of Release 4.0 | 
| 99699 | Buffer CCC too small for character set | 
| 79991 | Multi-Language and Unicode support of SAP applications |