Dynamically change the record length of a sequential file

nagarajan_guru · New User Joined: 21 Mar 2007 Posts: 6 Location: chennai

Hi All,

Is it possible to dynamically change the record length of a sequential file and revert back to the same record length? I can elaborate my question a little bit..

Suppose i create a sequential file with record length 50.Now I want to insert a new field.Now my question is "Is it possible to extend the record length when i want 2 insert a field and switch back to the same record length(ie 50) if i dont want to insert a field?"

Thanks and regards,
Naga.

enrico-sorichetti · Posted: Thu Apr 26, 2007 4:55 pm

If You need this kind of dynamic behavior it would be better to use variable length records

Anyway Yo cannot do that "in place" on datasets with fixed length records

regards

e.s

William Thompson · Posted: Thu Apr 26, 2007 5:28 pm

dick scherrer · Posted: Thu Apr 26, 2007 10:12 pm

Hello,

As has been posted - yes you can.

Any program that is going to read the file will need to know which record format it has read (often accomplished by using a "record code" that is put in the record).

You might want to post some of your data and how you want things to work for your situation - the "switch back" may present some "opportunities" depending on just how this is defined. If you can show some original records and then what will happen with them, it will be more clear.

jasorn · Active User Joined: 12 Jul 2006 Posts: 191 Location: USA

You can also do this kind of thing with fixed width datasets. The shorter records just get a filler. For me, the method I choose depends on the situation.