If History settings are enabled then:
- ResourceAssociation history is in the tables called ResourceAssociationHist, ResourceAssociationHistDelta, and ResourceAssociationHistoryDelta.
- Inventory data is stored in the tables that start with InvHist_.
The ResourceUpdateSummary table is a good location to find recently changed dataclasses, so that you know which InvHist_ table to look at.
For more information, see the HOWTO topic "Saving resource data history in the CMDB" at http://www.symantec.com/docs/HOWTO62644