WHR splitter in OS DB migration

Hi,

During export , table splitting preparation  .WHR files are created. and we need where splitter to split .WHR files again.

Now during table splitting preparation R3TA is called automatically.

Now when where splitter is called? is it automatically called by SAPINST , if yes at which stage? Or we need to manually split the .WHR files further.

Regards,

Arpit