Microsoft sees big potential in the database market for desktop and mobile users, and is upgrading, but also scaling down, its SQL Server to meet the needs of this emerging segment. There will be three or four versions of SQL Server 7.0 when it is released in the fourth quarter this year, Tom Kreyche, SQL Server product manager, says. They include one for small businesses, one for desktop and mobile users, and standard and enterprise versions which the software vendor usually offers. The SQL Server 7.0 desktop version will run on Windows 95, 98 and NT. Mr Kreyche says when Microsoft talks about scalability in SQL Server 7.0, it means two things - making the product more powerful, for example, to support clustering, or non-stop operation, and a very large database. It also means to scale down the product and introduce data-warehousing applications to laptop users, who can run their data and applications off-line and receive database updates on the road via a dial-up connection. Data-warehousing lets companies integrate and summarise information from different sources - for example, a company's different departments - so they can analyse it for business purposes. The enhanced SQL Server is easier to use than previous versions, Mr Kreyche says. For example, it allows dynamic, rather than fixed, allocation of memory depending on the number of users. It also supports auto response to emergence, as well as multi-site management of file groups, offering the flexibility to back up part of, rather than all, the data warehouse. SQL Server 7.0 is also integrated with an OLAP (on-line analytical processing) server, which is still a 'high-end and expensive component' for real-time query, Mr Kreyche says. The enterprise version of the new SQL Server, on the other hand, remains at the high end of the database spectrum. Microsoft recently put on the Net the TerraServer, a global atlas consisting of more than a trillion bytes of compressed aerial and satellite Earth photos, which runs on the SQL Server enterprise version. Accessible at www.terra server.microsoft.com, it is a combination of numeric, text and image data. Microsoft claims that with five terabytes of uncompressed image data, the TerraServer is bigger than the sum of all HTML pages on the Internet. If it were printed in an atlas with 500 pages per volume, it would span 2,000 volumes. So far, Microsoft has sent 200,000 pieces of SQL Server 7.0 beta 3 to worldwide users, the broadest beta ever done by a relational database management system vendor, Mr Kreyche says. It can now be ordered at www.microsoft . com/sql/beta/. Meanwhile, Oracle took a defensive measure last week and announced a migration tool aimed at Microsoft customers. Oracle's Migration Workbench will help SQL Server users migrate applications and the database to Oracle 8. No data will have to be re-entered, says Internet news service TechWeb. The product is in beta now, and will be available free by the end of the year. Also, Oracle will add a new set of graphical wizards to Oracle 8 by the year-end to help programmers develop applications more quickly.