Update and Delete tracking overhead
When a table in a TRACK CHANGES ON database has BACKUP [DATA]
ON, Update
and Delete
statements incur some additional
host I/O to record tracking information in the system catalog. No difference in the performance of
Update
and Delete
statements (or Merge
statements
that Update
or Delete
rows) resulting from this was noticed.
Insert statements do not incur this overhead, as the tracking in this case is combined with some
existing I/O that is already being performed.