Aggregation for Data Warehouse, Part 4

I have briefly mentioned the various approaches of providing aggregation for data warehouse. This post describes the third approach of using the Materialized View (Oracle) or Automated Summary Table (AST, DB2) from the database system.  I will describe the Pro’s and Con’s of using this approach.

A materialized view, like a table or a view, is a database object. A materialized view can contain the results of a query. It enables you to have a very efficient data access to the pre-aggregated data. It also helps you to maintain such aggregated data by simply defining the query, like creating a database view.

Aggregation for Data Warehouse, Part 3

This is my 3rd post related my series of postings on various techniques (see part 1) for providing aggregations in a data warehouse. I mentioned in part 2 that many ETL tools provide the support of creating, populating, and maintaining the aggregation tables. Today, I am describing the 2nd method – manually write the summarization process in a programming language.