Updating data.table by inserting new rows that are different from old rows

Question

I have two data.table(dt1 & dt2). dt1 is past product data and dt2 is present product data. I want to create a third data.table that inserts new rows from dt2 into dt1 only

Answer 1

Another alternative is to only rbind the subset of the data which is different (avoids the creation of one big data.table which contains dt1 and dt2)

dt3 <- rbind(dt1, setDT(dt2)[!dt1, on=c("Product", "Level", "Color")])
dt3[order(Product, ReviewDate),]