I have a large daily data feed which can contain up to around 5,000 ID's. I need to delete all pre-existing records in the DB that are not referenced in the new feed. Should I create a temporary table for these 5,000 ID's, and run a LEFT JOIN IF NULL DELETE statement? Or, is it all the same if I just pass the ID's over and run a DELETE IF NOT IN statement. My assumption is that MySQL would do the work of creating the temp table for me when using IN statements.
With a large set you may want to use an