When you try to get a backup with Expdp, if the process ends with error ORA-01426: numeric overflow, there are some alternative solutions.
During the process, the following error will occur and expdp will terminate.
ORA-02354: error in exporting/importing data
ORA-01426: numeric overflow
This error is seen in versions between 220.127.116.11 and 18.104.22.168. The problem is corrected as of version 22.214.171.124.
For the solution of the problem;
You can apply patch 14405152.
You can run expdp with ACCESS_METHOD = EXTERNAL_TABLE.
expdp hr DIRECTORY=dpump_dir1 DUMPFILE=expdat.dmp SCHEMAS=hr ACCESS_METHOD=EXTERNAL_TABLE