The OLTP system data for the Fitchwood Insurance Company is in a series of flat files. What process do you envision needed to extract the data and create the ERD shown in Figure? How often should the extraction process be performed? Should it be a static extract or an incremental extract?
The solution to the problem
The OLTP system stops working every Friday evening to backup the flat files to a different server. The flat files are extracted and copied to the UNIX server in the extraction process, then copied to the Oracle, and the star schema is rebuilt.
The extraction of data should be done weekly. It is preferable to carry out the extraction process after the system's backup is done on Friday nights. The extraction process is performed every Friday evening.
There are the following two ways to extract data:
Static extract: In the static extract, all the available data at that time in the source system is extracted.
Incremental extract: In this type of extraction, only the changed data from the last extraction is extracted. This can be performed with techniques such as capturing the change concerning the previous values or data.
It is difficult to determine whether static extract or incremental extract is the best option. It depends on the volume of the data. It is better to use an incremental extract process if the source system contains more volume of data.
See also: MDM Chapter 10 Problem and Exercise 2
إرسال تعليق