Do you know what a tape file is?
Can you delete a record from a tape file without copying it to another file?
ESDS files are like that......
The only thing you can do "in place" is to mark the record so that when any other program reads that record, it will know that the record is "deleted".
but i need the reason, why it cannot be deleted physically.
any special reasons?
Because there is no facility or process to remove the hole left when you would delete an ESDS record.
If the hole (the record's data replaced with low values?) was left in place, then all the other programs that read that file would have to know that the low value record was a deleted record - that it was "logically deleted".....