How do I exclude unchanged fields in Flashback query resultset? Is it possible to exclude unchanged fields in Flashback query resultset?
Consider I have following table
create table first_table
(
    id int generated as identity,
    name NVARCHAR2(1024),
    age smallint,
    notebook nclob,
    userpic clob,
    salary float
)

If the table has very frequent updates (e.g. on notebook field) following versioned query
select ROWID, VERSIONS_OPERATION, VERSIONS_STARTSCN, VERSIONS_STARTTIME, VERSIONS_XID, id, name, age, notebook, userpic, salary
from FIRST_TABLE versions between scn 1469193 and 1482882;

will pull heavy userpic value for every row even though it's the same.
Can I somehow avoid that and instead get NULLs for unchanged values ?
Is there a way to excluded unchanged fields from versioned response?

Not really.
Flashback uses the information found in UNDO. Flashback Data Archive stores the results from the Log files in a table.
So, you get ALL of the data when you do a Flashback query.
The common method is to use LAG + DECODE.  But, I'm afraid that this will problematic for your LOB columns.
Personally, I'd pawn off the problem to the UI (Display Tier).