When a client simply updates an old row in their data base it will not show up in Datagran. To be able to solve this here’s the strategy:

• Create a column update_at
• Whenever a row is updated, update that field.
• Use that field as key for key-based sync .

it will duplicate rows BUT you can eliminate unnecessary rows by checking updated_at  column.

Another option is just to switch to Full Table (not available in every integration).