It is recommended to refresh your data no less than monthly, as that is how frequent GivingDNA's data insights are refreshed.
When refreshing your constituent and gift files it is recommended to load all of your constituents and gifts. This way any changes made in your CRM to people or gifts, will be reflected on GivingDNA, and anything new will be included too.
GivingDNA recognizes donor IDs and gift IDs, that have previously been uploaded. The platform will not duplicate if a preexisting ID is uploaded again; it will recognize preexisting IDs and make changes if there are any to that constituent or gift being uploaded again (ex: a new address is associated with a person already on GivingDNA). New IDs will be recognized and added to the total count of constituents and gifts uploaded onto the platform.
While it is recommended to upload all of your constituents and gifts each time you refresh data in order to acknowledge any changes to those already on GivingDNA, delta files can also be loaded picking up where the previous files left off. This may mean any changes to a constituent or gift in your CRM will not be reflected on GivingDNA.