datasource collection filter

Currently it is possible to control discovery of instances for a datasource with filters.  It is not, however, possible to avoid data collection in a similar manner.  Adding a collection filter (bypass?) capability could greatly improve performance, especially considering cases like interfaces, where 25+ datapoints are collected.  In that case, a collection filter might indicate "primary" datapoints always collected, and then depending on their state, skip the rest (e.g., ifAdminStatus == down or ifOperStatus == down).  I know this makes it more complex, which is not good, but a generic facility for bypassing heavy data collection not really needed would be a great addition to LM.

Thanks,

Mark