created
tells you when given the data (e.g. attachment to a form for the orbeon_form_data_attach
).last_modified
tells you when the data was last changed.username
tells you who did that change.deleted
tells you if the data is marked as deleted, and hence invisible to users.created
and last_modified
have the same value. Then, when this data is modified, another row is added: created
is copied over and last_modified
is set to the current time stamp.last_modified
which is set to the current time stamp and deleted
which is set to Y
.