SQL Merge success

Today we setup a merge statement in writing to SQL , we selected user statement

 

Now with adding 1 record we were able to write down our custom sql to merge successfully with custom validation 

Question to Team ETL,
1. how to do optimise this better? 
2. Do we split the logic into update separately ? or one script to update is fine
3. Is it better to do this via procedure , if yes how?



MERGE [items].[basecamp].[checklist_tasks] AS target
USING (
    VALUES (?, ?, ?, ?)
) AS source (MasterTaskID, AssignedEmployeeID, DueDate, RecurrenceRuleID)
ON target.MasterTaskID = source.MasterTaskID
   AND target.DueDate = source.DueDate
WHEN MATCHED AND target.Status = 'Not Started' THEN
    UPDATE SET
        AssignedEmployeeID = source.AssignedEmployeeID,
        RecurrenceRuleID = source.RecurrenceRuleID,
        Status = 'Not Started'
WHEN NOT MATCHED THEN
    INSERT (MasterTaskID, AssignedEmployeeID, DueDate, Status, RecurrenceRuleID)
    VALUES (source.MasterTaskID, source.AssignedEmployeeID, source.DueDate, 'Not Started', source.RecurrenceRuleID);
 

For small datasets your solution is perfect. 
One script is always better than several

For large datasets loading data into staging table and than running the script will provide a better performance
 

For large datasets loading data into staging table and than running the script will provide a better performance

Thank you , I will remember this for future projects