If you code with RECGM F
Disadvantages:
1) The read and write operations will be slow. 


Sequentially reading the entire file could be slower since an i/o would give less of the file. (ie more i/o although there are ways around this via chaining ccws, etc.) Each individual i/o would actually be a bit faster since you would be using BSAM which I would bet will out perform QSAM on an individual i/o also the amount of data being transfered per read would be smaller.



2) It requires more buffer space also.
Not really true. Buffers would be smaller.

Advantages:
1) The predecessor job can not see the blocked data.
The data is not blocked - there is no blocked data

Please correct me if I am wrong.

Thanks
Lavanya T