Near real-time with traditional data warehouse architectures: factors and how-to

Traditional data warehouses integrate new data during lengthy offline periods, with indexes being dropped and rebuilt for efficiency reasons. There is the idea that these and other factors make them unfit for realtime warehousing. We analyze how a set of factors influence near-realtime and frequent loading capabilities, and what can be done to improve near-realtime capacity using a traditional architecture. We analyze how the query workload affects and is affected by the ETL process and the influence of factors such as the type of load strategy, the size of the load data, indexing, integrity constraints, refresh activity over summary data, and fact table partitioning. We evaluate the factors experimentally and show that partitioning is an important factor to deliver near-realtime capacity.