Обсуждение: PCLabs Survey, Part VIII: Data Warehousing and Reporting

Data Warehousing and Reporting
- availability       - fast loader (direct to disk pages) included       - loader provides data transformation and
cleansingtools        - can load and index simultaneously       - incremental load possible       - can delay
constraintchecking during a bulk load       - can continue to insert data while index is being built
 
- precalculation of summary information       - included OLAP server       - summary tables (a.k.a. materialized views)
     - summary tables understand dimensional hierarchies (e.g. time)       - automatic refresh on data change       -
scheduledrefresh
 
- can use data sampling to speed processing
- Top N query
- Top % query
- RANK function
- CUBE and ROLLUP functions

Marc G. Fournier                   ICQ#7615664               IRC Nick: Scrappy
Systems Administrator @ hub.org 
primary: scrappy@hub.org           secondary: scrappy@{freebsd|postgresql}.org