You need to modify an IDEAL sequential dataview that is modelled in Datadictionary but you have forgotten how to do that as Ideal sequential dataviews are now created/modified in IDEAL.
Environment
Release: All supported releases. Component: Ideal.
Resolution
Go into Datadictionary online by using CICS transaction DDOL.
Select FILE Maintenance mode.
DISPLAY the DATAVIEW structure to pick up the name of the related FILE and RECORD occurrences.
RESTORE the FILE in PROD status into a test version such as T001.
DEFINE the RECORD where you can change/add columns.
Then MODIFY the ELEMENT (put Y in the newly added columns and press PF9 Apply).
Run MODIFY FILE to change the record length/blocksize.
When done, run VERIFY FILE - if no errors then COPY FILE to PROD and ENABLE FILE.
RESTORE the DATAVIEW from PROD to a test version like T001.
Then COPY the DATAVIEW from test to PROD status.
Go into IDEAL and run CAT DVW dataview name v PROD.