Logically, why would the ORA-00600 error relate to your Oracle to Postgres migration? You are making changes in Postgres, but not on the Oracle side. When did you get the ORA-00600?
Im trying to migrate orqcle schema to poatgres via python script .
I suggest you look at ora2pg, which worked flawlessly for me not only in converting the Oracle schema but in generating load files for Postgresql COPY.