On 2018/03/28 04:30, Neil Chandler wrote:
If you are doing updates by rowid, you need to set the appropriate level of
supplemental logging to ensure that the relevant data (pk/uk/all columns) is
captured in the redo regardless of the modification statement to ensure the
row on the destination can be identified and manipulated. This will increase
the amount of redo written and therefore have an impact on redo performance.
PK supplemental logging will add minimal overhead, supplementally logging all
columns may be devastating depending upon the size of each row.
