Use a full load approach and overwrite the existing data in the Data Warehouse every time.

Create a new table in the Data Warehouse for each incremental load and merge the data manually.

Use a combination of a high-water mark technique and a SQL query to filter out the new or updated records based on the 'last_modified_date'.

Disable the 'last_modified_date' column and rely on the source system to automatically handle the incremental load.