Once we have a sense of the rate at which we see distinct grouphashes and are confident we can safely do this, apply the new-years-hanger effect to grouphashes:
Run a migration to mark them all unseen (new status value)
Each time we see one, mark it seen
Wait 90 days
Run another migration to delete any which haven't been seen
Once metadata is fully rolled out (and so we can distinguish newly-created hashes from old ones by the date_added value, or lack thereof), we might start by just deleting all older grouphashes missing a group.
Once we have a sense of the rate at which we see distinct grouphashes and are confident we can safely do this, apply the new-years-hanger effect to grouphashes:
Once metadata is fully rolled out (and so we can distinguish newly-created hashes from old ones by the
date_addedvalue, or lack thereof), we might start by just deleting all older grouphashes missing a group.