Currently looking to retrieve information on the last date on which each file has been accessed (as opposed to simply modified). Any recommendations on current schemas, alone or in combination, would be welcome.
This is dependent on the connector used and where the data is stored. Different connectors are able to pull different metadata from the underlying storage platform, and different storage platforms store and maintain different sets of metadata per Document.
For example, the HCP connectors will include the "X-HCP-ChangeTimeMilliseconds" and "X-HCP-ChangeTimeString" fields on all Documents.
The "Local Filesystem Connector" can expose POSIX metadata stored in the file system, using fields such as "HCI_modifiedDateMillis"/"HCI_modifiedDateString" (mtime), "HCI_accessDateMillis" (atime), or "HCI_createdDateMillis" (ctime).
Hope this helps,
Retrieving data ...