The transfer method only determines how the data is transferred.

IDoc transfer method: A data IDoc consists of a control record, a data record, and a status record. The control record contains administration information such as receiver, sender, and client. The status record describes the status of the IDoc, for example "MODIFIED". The data stores in the ALE INBOX and outbox have to be emptied or reorganized.

PSA (tRFC) transfer method: With this transfer method, a transactional Remote Function Call is used to transfer the data directly from the source system to the SAP BW. Here, there is the option of STORING the data in the PSA (the tables have the same structure as the transfer structure.) This is the preferred transfer method, because it improves performance BETTER than the IDoc method. When you USE tRFCs to transfer data, the maximum number of fields that can be used is restricted to 255. The length of a data record is also restricted to 1962 bytes when you use tRFCs (IDoc --> 1000 bytes.)

The transfer method only determines how the data is transferred.

IDoc transfer method: A data IDoc consists of a control record, a data record, and a status record. The control record contains administration information such as receiver, sender, and client. The status record describes the status of the IDoc, for example "modified". The data stores in the ALE inbox and outbox have to be emptied or reorganized.

PSA (tRFC) transfer method: With this transfer method, a transactional Remote Function Call is used to transfer the data directly from the source system to the SAP BW. Here, there is the option of storing the data in the PSA (the tables have the same structure as the transfer structure.) This is the preferred transfer method, because it improves performance better than the IDoc method. When you use tRFCs to transfer data, the maximum number of fields that can be used is restricted to 255. The length of a data record is also restricted to 1962 bytes when you use tRFCs (IDoc --> 1000 bytes.)