RE: Change to Physical File

rpg400-l-request@xxxxxxxxxxxx wrote:

>   2. Change to Physical File (Don Wereschuk)
>
>I need some help on doing a change to a PF. After running CHGPF on the
>file with a new field at the end of the file, do I have to re-compile
>all the programs that use that file ( both PF and LF) or just the
>programs that use the new field?

Don:

"It depends..."

Usually, if your LFs explicitly list the fields, then their record format 
identifier won't change in this case. No need to recompile such LFs nor any 
programs that are compiled over them.

However, a lot of developers created all (or most or many) LFs with implicit 
selection of all fields rather than listing only those fields that are used. 
That can potentially mess things up.

IBM does some kind of readjustment of pointers or something within at least 
some kinds of LFs when CHGPF is done to the base PF. The LF doesn't get 
recreated but somehow modified in place as needed. Somebody (who knows) should 
write up a FAQ or something that outlines the various interdependencies. Even 
adding a field in the middle can leave a properly defined LF without format ID 
changes.

AFAIK, practically speaking from the list, comparing the format ID of the LF 
from DSPFD to the format ID shown by DSPPGMREF is the only good way to predict 
if a recompile is needed. If mismatches are found, I would then recompile 
_both_ the LF and any related programs even if the LF doesn't technically need 
it.

Tom Liotta