# Use DBMS_DATAPUMP to validate impdp user/pwd DIRECTORY=dp_dir DUMPFILE=exp.dmp SQLFILE=check.sql
To appreciate the gravity of ORA-39126, one must understand the Data Pump architecture. The KUPW (Data Pump Worker) process handles the actual loading of data into tables. The function PREPARE-DATA-IMP (import data preparation) is responsible for setting up the environment to receive a specific table’s data—evaluating constraints, preparing indexes, and initializing the stream. The number 71 refers to a specific internal subroutine within that preparation phase.
Issues often arise when importing system-managed schemas (like SYSMAN or SYS ) or when there are character set mismatches between the source and target environments.