Using External Tables is becoming more
and more popular, eliminating the need of SQL*Loader to load tables.
However, you also face issues while working with external tables, one
of which is described here:
When you perform a SELECT operation on
an external table, you may face something similar to the following:
ORA-29400: data cartridge error
KUP-04063: unable to open log file EXTERN_17063.log
KUP-04040: file TEST.TXT in TEST_DIR not found
ORA-06512: at “SYS.ORACLE_LOADER”, line 19”