SORTS

only for RuBoard - do not distribute or recompile

SORTS

I have included a small section on sorts in this chapter, describing products, because, in my experience, it is something often neglected by data warehouse designers and yet can have a profound effect on the performance, particularly summarizing and loading.

Sorting inside the database is often very slow. Using sorting programs provided by the operating system can be up to four times faster. Using a high-performance sort utility can be 10 times as fast.

There are also some other useful features that the better sorting utilities provide:

Record selection.   This enables some records to be selected while others are ignored.

Summarizing.   You can actually produce your daily, weekly, or monthly summaries using nothing more than the sort utility.

Reformatting.   This enables required fields to be extracted, rearranged, and written out in a new format.

Not only can the utilities save us in processing effort; they can also save development effort. We don't always have to design and build summarization software for instance.

So, instead of loading data and then building summaries using SQL, consider building the summary using a high-performance sort and loading the summary into the database using the RDBMS loader utility.

only for RuBoard - do not distribute or recompile


Designing a Data Warehouse . Supporting Customer Relationship Management
Designing A Data Warehouse: Supporting Customer Relationship Management
ISBN: 0130897124
EAN: 2147483647
Year: 2000
Pages: 96
Authors: Chris Todman

flylib.com © 2008-2017.
If you may any questions please contact us: flylib@qtcs.net