Inspector - Add extra control over backup thresholds

[Adedba]

It would be good to be able to set backup thresholds at a database level as well as having global thresholds for the server.

For example:

You may want to set the global threshold to warn if a full backup has not been taken for 7 days but you may be running nightly system database backups so you actually want to have a separate threshold for your system databases.

Ideally we should have a thresholds table that allows the user to add a servername/database name combination along with the relevant thresholds for FULL, DIFF and LOG. When the report runs it can check for existence of these thresholds first and use them for a given server/db otherwise default to the global values set in the main Settings table.