Thanks for the reply!

If I understand you correctly, which I think I don't, I would need to know N?

My example might also not have been clear enough - I do not want to insert rows for every missing n - just a single row at any discontinuety.

eg.

Nr Value
-----------
1 10
2 5
10 3
11 8


should become

Nr Value
-----------
1 10
2 5
3 NULL (in fact ... Nr can be anything between 3 and 9 - it will have the same result on the graph in the end)
10 3
11 8


Thanks again for any thoughts


What would probably be possible, but I don't know how elegant or optimal a solution, would be to do something like:

Select
x.NR,
NULL as Value
from
(select
(NR + 1) as NR,
LEAD(NR,1,null) OVER (PARTITION by (some other field ..hehe) ORDER BY NR) - NR as difference
from
Some_table
) x
where difference > 1

This should produce a record for each discontinuety.
I can then UNION this with the SELECT Nr, Value FROM SOME_TABLE

It should work, but would it be the fastest solution? Most probably not ...