That is a key assumption, say experts such as independent database analyst Curt Monash and Miro Consulting's Colon. Based on Oracle's recommended configuration and price list, customers who do not already own transferable enterprise Oracle database licenses with the given options would need to pay an additional $3.2 million (see Monash's detailed calculations.)

That increases the price 140%, and makes the price-per-TB of the Database Machine about $33,000 -- higher than Netezza's and slightly lower than Teradata's.

Netezza, which had blasted the Exadata and Database Machine as products that had been cobbled together "with glue and spit," declined to confirm or dispute the price of its appliance listed by Ellison. But in a statement, Netezza said, "We do believe we will compete very favorably on price/performance with the Oracle Database Machine and Exadata entrants in the market."

Upselling Customers to Faster, Pricier Configurations

Teradata's Lea, meanwhile, says that Oracle's price-per-TB only applies if customers buy their Exadata Storage Servers configured with 1 TB SATA drives rather than the faster, smaller 300 GB Serial-Attached SCSI (SAS) drives.

Oracle charges the same price whichever drives that users pick. That means users who pick the faster SAS drives would pay 70% more per TB. That raises the price-per-TB for Oracle users with fully-transferrable licenses to $46,000, or 31% more than Teradata, and up to $110,000 per TB for those lacking any Oracle database licenses, which is 314% more than Teradata's price.

Colon says Database Machine customers shouldn't be surprised if they find themselves steered by Oracle's sales representatives toward the faster-but-pricier SAS drives.

"There is always the vanilla out-of-the-box solution that Oracle doesn't really recommend," Colon said. "You really have two options: buy what they recommend today, or buy it eventually down the road."

Also, Oracle's price-per-TB are based on the amount of raw storage you buy, rather than the amount of actual user data you'll be able to store. Databases typically need extra space to create indexes of the data, temporary read/write working spaces, and redundant and replicated data for backup purposes.

Some of that space can be reclaimed, says Monash, depending on how efficiently a database compresses the data. Still, a database with raw tables that take up 10 TB may actually require 20-30 TB of storage overall, even after compression.

Lea claims that Teradata data warehouses, despite less advanced compression technology than Oracle's, still require less disk overall to deliver peak performance.

"To optimize an Oracle environment, there is a lot of data duplication," Lea said.