Amazon Redshift achieves efficient storage and optimum query performance through a combinationof massively parallel processing, columnar data storage, and very efficient, targeted datacompression encoding schemes. Columnar storage for database tables is an important factor in optimizing analytic queryperformance because it drastically reduces the overall disk I/O requirements and reduces theamount of data you need to load from disk. Reference: http://docs.aws.amazon.com/redshift/latest/dg/c_columnar_storage_disk_mem_mgmnt.html