Microsoft Office Tutorials and References
In Depth Information
Figure 1-2. HR Relational Tables from the AdventureWorks database
We strongly recommend you download and install the adventureWorks sample database from
msftdbprodsamples.codeplex.com/downloads/get/417885 . You’ll get the most out of this chapter and the others if
you can follow along.
Note
OLTP is not meant for slicing and dicing the data, and it’s definitely not meant to be used to make key decisions
based on the data. OLTP is real-time, and it’s optimized for performance during Read/Write operations specifically
for a faster response. For example, an OLTP system is meant to support an airline reservation system that needs to
publish airline schedules, tariffs, and availability and at the same support transactions related to ticket reservations
and cancellations. The system cannot be used for analysis because that would degrade the performance of routine
transactions. Moreover, a normalized structure is not suitable for analysis (for example, revenue analysis for an
airline) because this involves joins between various tables to pull relevant information, leading to increased query
complexity.
Take a look at Figure 1-3 . Notice how information is limited or incomplete. You cannot tell what the numbers or
codes are for various columns. To get more information on these values, you need to run a query that joins this table
with others, and the query would become bigger and bigger as the number of relational tables increases.
Figure 1-3. A table with incomplete information
 
 
Search JabSto ::




Custom Search