Materialized Views

Data warehouses are used to extract additional value from an organization’s data store by using that data for additional analysis. This analysis usually involves aggregation of the underlying data, a process that can take a significant amount of time in the production environment.

Materialized views are one way to reduce the runtime cost of these aggregations. A materialized view allows you to precalculate summary information, which not only avoids the need to perform these resource-intensive tasks at runtime, but also allows multiple queries looking for the same aggregation to reuse the same summaries. Materialized views come with their own set of refresh management options. You can choose to completely refresh the summaries in a materialized view, to perform an incremental refresh, or even to refresh summaries in materialized views every time an underlying table is updated. This last option gives you absolutely up-to-date summary information, but does impose overhead on every write operation to a table with one or....