The Data Compare Settings are used to control the comparison of data in Data Sync. You can change this on a column by column basis in the Schema Map.
The Ignore setting will prevent Data Sync comparing the value and generating an UPDATE action for this column, however if any other column causes an UPDATE action then the value of this column will be added to the change set. This is useful when you want to force a columns value to always be sent to the target.
Data Compare Mode
This is used to control how the source and target values are compared for UPDATE actions.
Data Sync default comparison mode is to compare that the values from each side are equal.
Default configuration where a change is detected when the values are not equal.
Where a change is detected when the values are equal.
Where a change is detected when the target value is less than the source. Typically used in 2-Way sync scenarios to prevent updates to a row when the Modified Date is greater on the Target.
Where a change is detected when the target value is greater than the source.
Where a change is detected when the target value is null or empty and the source has a value.
When the source has a value and the target is not equal to the source.
The Data Compare Mode typically is used in conjunction with the Trigger Update setting. This setting is used to decide what change(s) will cause an UPDATE action to be created.
For example in 2-Way sync where you have a modified DateTime value on each side which is updated when the row is changed. You would create 2 projects each running in a different direction.
The First project you would set TriggerUpdate=False on all columns in the Schema Map except for Modified and then set the Mode=TargetLessThan for the Modified Column. This causes Data Sync to only compare the values on this row when then Target Modified value is less than the source. i.e. the Source is more recent.
The Second project can now be setup as normal but in reverse, you then set the projects to run after each other in Ouvvi or the Run Tool.