2538401 - Guided Answers: Client Copy performance issues and troubleshooting

Customer often encounter various problems during client copy, and client copy performance issue may be the biggest headache.
SAP product support team can receive kinds of incidents about performance issues, for example,
why client import time is much longer than client export time?
it took 30 hours to finish client copy last year, but it took 50 hours for the same client this year, why?
client copy seems hang, how can I see if it's still running?
....

We will introduce client copy related information/KBA/notes here to give you a clear picture about it.
Besides, we also collected some well-known errors during client copy which may help you avoid such problems during client copy.

Release independent

Client Copy performance, slow, PSAPUNDO, PSAPTEMP, client size, size of client, tablespace, parallel process, HANA, Sybase, Oracle, MSS, SCC3, SCC4, SCC5, SCC7, SCC8, SCC9, SCCL, client transport, SM50, DIR_TRANS, DDIC error, RBDLSMAP, compute_overflow, CX_SY_CONVERSION_OVERFLOW, CONVT_OVERFLOW, Source client, MESSAGE_TYPE_UNKNOWN, RC: 10, not exist in nametab, Double Key table , KBA , BC-CTS-CCO , Client Copy (For ByD issues select BC-TLM-CP) , Problem