How do I track changes to a dataset?

[capilarity]

We get a weekly ingest of a data set for our vulnerability management. Each line contains a unique value matching a vulnerability with a server

I want to be able to report on:

a. how many new vulnerabilities are in this weeks report compared to last week and

b. how many vulnerabilities have been fixed (so are not reported) in this weeks list compared to last week

I'm looking for splunk to tell me whats new and whats missing week by week but also track these over the long term. 

Cant seem to get any meaningful results with a 'set diff' search

Any help gratefully received!!

[somesoni2]

Try something like this

your base search for getting vulnerability data for each host, set time range to last two weeks OR 14 days
| eval period=if(_time>=relative_time(now(),"-7d@d"),"This_Week","Last_Week")
| stats values(period) as periods,..any other fields... by host vulnerability_id
| eval remarks=case(mvcount(periods)=2,"Repeat Vulnerability",periods="This_Week","New Vulnerability", true(),"Fixed Vulnerability")