Google has doubled the capacity of its enterprise search device as well as adding new query capabilities.

The Search Appliance's maximum capacity has been increased to 30 million documents, up from 15 million, said Google. The increased capacity comes via a software upgrade that also includes search query enhancements.

The software upgrade is available to Search Appliance owners with an active support plan. All owners get access to the search query enhancements, but they have to pay extra if they want additional capacity.

The Search Appliance, introduced in 2002, is a hardware box with Google search engine software designed to index and retrieve documents stored in enterprise servers.

The Search Appliance model that can index up to 30 million documents is the GB-8008, the line's most advanced. Google doesn't disclose its price but its 30 million document configuration can cost "in the high six figures," said Matthew Glotzbach, head of products for the Google Enterprise unit.

The intermediate model, the GB-5005, has a 10 million document capacity, while the entry model, the GB-1001, starts at US$30,000 and can index up to 3 million documents.

Although the off-the-shelf GB-8008 now has a maximum capacity of 30 million documents, Google can make the product index more documents through custom configurations. "We can easily do a 100-million document system," he said.

With this week's upgrade, all Search Appliance models have gained the ability to limit search results by a date range. For example, a user now can retrieve documents published in, say, the first quarter of 2004.

The Search Appliance now also can narrow search results by number range. This might be useful for ecommerce companies, so they can let their customers find products within a specific price range.

The purchase of a Search Appliance includes a 2-year support plan, which in turn includes software updates and telephone technical assistance.

Google also has a smaller search device called the Google Mini, aimed at departments and small and medium-sized businesses, as well as an enterprise desktop search application.

Google competes with vendors like Autonomy and FAST Search & Transfer ASA in the enterprise search market.