Oracle9iR2 Data Warehousing

5.8 Summary

In this chapter we looked at the ETL process. Various techniques were discussed to identify rows that changed on the source system as part of the extraction process, and Oracle change data capture was introduced. A number of types of transformations that are common to a data warehouse were discussed. Examples were shown performing transformations during the load process and using staging tables inside the Oracle database. Techniques used to load the warehouse were described including SQL*Loader, external tables, and transportable tablespaces. Moving data from the staging system to the warehouse tables can be done using exchange partition, direct path insert, or CREATE TABLE AS SELECT. In Chapter 6, we'll look at Oracle Warehouse Builder, which uses many of the functions discussed in this chapter to help you load your data warehouse.