%Monitor class to collect and manage part of the Monitor History Database.
This class collects the SYS.History.SysData samples for the System Usage Metrics,
as defined in the Usage and Database classes, at somewhat longer intervals than the
History class (default of 5 minutes).
By default the SysData collection is kept for 7 days and then purged.
The number of days to keep may be modified using SYS.History.PerfData:SetPurge()
The SysData samples can be automatically rolled up at the end of each day into
Hourly (SYS.History.Hourly) or Daily (SYS.History Daily) summaries, which can be
kept for longer periods.
Get the basic SYS.History.SysData sample for the Monitor History Database.
This method also handles purging and accumulation of the Detail metrics
into the long term database (SYS.History.Hourly and SYS.History.Daily).
Initialize property values