Retaining one of top customers, Teradata announced on Wednesday that it has reached an agreement to extend its 21-year relationship with retail giant Walmart.

Teradata said the agreement will drive a refresh of Walmart's petabyte-scale data warehousing deployment and will also include a research and development program aimed at improving the retailer's competitive advantage.

Walmart executives could not be reached in time to comment on how the deal might impact its Hewlett-Packard Neoview deployment. Teradata lost a competitive bid against Neoview in 2007 when the then-new platform was chosen for Walmart's Retail Link data warehouse.

Neoview had a bit of an inside track in 2007 in that it was championed by HP CIO Randy Mott, who had previously served as Walmart's CIO and was a 22-year veteran of the retailer. Mott left Walmart to become CIO at Dell before he joined HP in 2005.

Retail Link is Walmart's online warehouse for sharing up-to-date point-of-sale information with suppliers. Back in 2007, Retail Link tracked some 800 million transactions per day, with detail down to the store and item level.

Some question whether Neoview ever fulfilled its promised scale at Walmart. There have been recent rumors, denied by HP, that development work on the Neoview platform has been suspended. Meanwhile, Teradata has continued to power Walmart's enterprise data warehouse (EDW). In 2008, analyst Curt Monash pegged Walmart as Teradata's second-largest customer in terms of data scale with a 2.5-petabyte deployment -- smaller than eBay's 4-petabyte deployment but larger than Bank of America's 1.5-petabyte warehouse.

As part of their new agreement, Walmart's Teradata's deployment will be expanded and refreshed. The latest Teradata products are expected to deliver a 50% reduction in data center floor space and a 40% reduction in energy consumption.

"We will be able to leverage scalability, processing power, and storage capacity, along with software enhancements," said Jose Hernandez, Walmart’s chief technology officer and senior vice president of infrastructure, in a statement. "Consistent with our sustainability initiatives, this expansion will result in a significant reduction in our data center power and cooling footprint."

Data-scale, query-performance and price-per-terabyte stats get lots of attention in so-called big data deployments. But Teradata has sought to differentiate its analytic know-how and consulting services.

"Users know they have many good technology choices from many sources, but the hardware is the least of it," said Forrester analyst James Kobielus. "Customers want the vendors to be able to come in and help them rewrite queries and reorganize the database to optimize the platform."

Demands for real-time data integration and predictive modeling are even more daunting for customers, so these are areas where Teradata has expanded its services capabilities. Consultants now account for more than half of Teradata's employees, and most focus on specific industries.

Teradata says its platform and services are used by seven out of the top ten retailers globally.