Extraction : Error occurred in the data selection or error 4 when starting the extraction program

Context : Extraction
System : BW
Error Description :-

Error occurred in the data selection' or 'error 4 when starting the extraction program.' (R3019) or 'error 8 when starting the extraction program. (R3019) 'Error in the source system' (RSM340)

Solution :-

Check table ROIDOCPRMS in your OLTP system.If the field BTCSYSTEM exists, it must contain the names of an available application server of the OLTP system or it must be empty.If you enter the application server there, pay attention to the spelling:the name must be entered (upper/lower case) as specified via Transaction SM51 in field "Host name"! This server must be capable of starting a background process for data extraction