If I understand the purpose of Retention policy is to avoid having huge backup Catalog.
for instance, if you have differential on week days and Full backup on week ends ,Full the last week end of the Month, Full the last week end of the year, some do it the first week end of the following year if the week end does fall on December 31st.
to my understanding As long as your backups have run without missing any data, then regardless of the Retention Policy you have, your Backed up Data stays there and you can recover it.
I have seen some environments they configure Retention for 6 Months, Year, Infinity...etc..., I was wondering if the purpose of this Retention is to have smaller backup catalog ?
I also want to know, for instance if you want to look for a folder to restore from 5 yeas ago , would the Catalog expand and get bigger in order to have all the data from 5 years ago in order to find the folder we are looking for ?
any clarifications will be very much appreciated.