Data Warehousing :: Dimension With Over 330M Records / Need Of Updates

I have a table that is increasing quite largely each day. By now, I have average 300 million of records over 2.5 years. Before we received our new interface, the data we received was aggregated and thus not that big.The problem is that the table is so huge that I cannot use the Slowly Changing Component. I was thinking about making a temp table where I load the incremental data before I load it into the final data mart table.Based on this temporary table I use a script to compare the temp data with the already existing data in the data mart. However, this requires a compare of each records (300 mil records).