Data is not always stored in rows

Data is not always stored in rows

Many are not aware of the significant differences between DBMS architectures. One architecture that most are unfamiliar with is column-oriented DBMS. These DBMS store all columns of a table together as opposed to storing all the columns of a row together.

For example, instead of:

John Smith 123 Main St. Anywhere, CA USA
Jane Doe 456 Elm St. Anywhere, CA USA

John Jane
Smith Doe
123 Main St. 456 Elm St.
Anywhere Anywhere
CA CA
USA USA

is stored. Single-column linear functions such as AVG, MIN, MAX, and SUM are going to perform well in this type of storage approach because all the data needed is together and there will be fewer I/Os. Extraneous columns not relevant to the linear function do not need to be "skipped over" in this architecture. Multi-column retrievals and joins are more conducive to a row-oriented storage approach where predictable linear function needs can be pre-calculated.

Additionally, the storage method facilitates compression because it is likely that value repeatability will occur from one row to the next as with CA and USA in the example above. This facilitates compression, especially for low cardinality columns.

On balance however, all things being equal, this approach is not conducive to the active, mixed-workload environments that comprise today's best practice data warehouses.

For more information, check out SearchCRM's

    Requires Free Membership to View

    When you register, you'll begin receiving targeted emails from my team of award-winning editorial writers on the latest customer relationship management (CRM)and call center technology issues today. Our goal is to keep you informed on the hottest issues facing this fast-changing industry.

    Hannah Smalltree, Editorial Director

    By submitting your registration information to SearchCRM.com you agree to receive email communications from TechTarget and TechTarget partners. We encourage you to read our Privacy Policy which contains important disclosures about how we collect and use your registration and other information. If you reside outside of the United States, by submitting this registration information you consent to having your personal data transferred to and processed in the United States. Your use of SearchCRM.com is governed by our Terms of Use. You may contact us at webmaster@TechTarget.com.

Best Web Links on Data Warehousing.


This was first published in July 2002

Join the conversationComment

Share
Comments

    Results

    Contribute to the conversation

    All fields are required. Comments will appear at the bottom of the article.

    Disclaimer: Our Tips Exchange is a forum for you to share technical advice and expertise with your peers and to learn from other enterprise IT professionals. TechTarget provides the infrastructure to facilitate this sharing of information. However, we cannot guarantee the accuracy or validity of the material submitted. You agree that your use of the Ask The Expert services and your reliance on any questions, answers, information or other materials received through this Web site is at your own risk.