Check if data from database is up to date I'm storing some data from database, and want to check if that data is up-to-date from the database version. What is the best way to do this?

My ideas:


Getting checksum from the table and comparing with last update
checksum (must be an overkill) 
Getting table modification date and
comparing with current data update time
Just keep "last updated/last stored" as timestamp value. Easy to do even on a record level (i.e. for each record, and not for whole table).