Here is a little tip I often advise my customers on.....
The default data retention in OpsMgr is 7 days for most data types:
These are default settings which work well for a large cross section of different agent counts. In MOM 2005 - we defaulted to 4 days. Many customers, especially with large agent counts, would have to reduce that in MOM 2005 down to 2 days to keep a manageable Onepoint DB size.
That being said - to boost UI performance, and reduce OpsDB database size - consider reducing these values down to your real business requirements. For a new, out of the box management group - I advise my customers to set these to 2 days. This will keep less noise in your database as you deploy, and tune, agents and management packs. This keeps a smaller DB, and a more responsive UI, in large agent count environments.
Essentially - set each value to "2" except for Performance Signature, which we will change to 1. Performance Signature is unique.... the setting here isnt actually "Days" of retention. It is "business cycles". This is for self-tuning threshold ONLY. This data is used for calculating business cycle based self-tuning thresholds. There is NO REASON for this ever to be larger than the default of "2" business cycles.... and large agent count environments can see a performance benefit by bumping this down to only keeping "1" business cycle.
Then - once your Management group is fully deployed, and you have tuned your alert, performance, event, and state data.... IF you have a business requirement to keep this data for longer - bump it up.
Keep in mind - this will NOT cause you to groom out Alerts that are open - only closed alerts, and still will keep your closed alerts around for a couple days.
These settings have no impact on the data that is being written to the data warehouse - so any alert, event, or perf data needed will always be there.