When systems vendors pick embedded databases for use inside equipment like switches, routers, and SAN servers, they’re typically torn between solutions that either cut costs or boost performance, but can't do both.

Not anymore, according to Solid Information Technology Corp., which earlier this week announced some software called AdaptableEngine (see Solid Unveils Database, Sun Partnership). The database enables vendors to trade off price and performance to get the best balance for different applications, says Solid.

Solid's claims are causing a bit of a stir in the arcane world of embedded systems, and to understand why calls for a bit of background.

Up to now, Solid's offered a product called FlowEngine, a relational, real-time distributed database that's designed to work in confined spaces across multiple geographic locations. FlowEngine coordinates routing tables across multiple sites within routers, for instance, or gives network management systems the means to get feedback from remote probes.

A central characteristic of FlowEngine is that it stores data on disk instead of in memory. This approach has cost advantages for many customers, Solid says, since it's historically been cheaper to use disk storage than RAM (random access memory).

Recently, though, there's been a push in the embedded systems industry to use RAM for data storage. Putting databases in RAM can cost more, the thinking goes, but it results in faster performance. With the introduction of AdaptableEngine, a supplement to FlowEngine that's set to ship in the first quarter of 2003, Solid's giving developers a choice to store parts of databases in either disk or RAM. "We let you select table-by-table whether to run information on disk or in memory," says Malcolm Colton, VP of worldwide marketing.

He claims that by giving customers the option to split data between disk and RAM, cost advantages are maintained, while performance can rise an order of magnitude for some devices.

By adding the choice, Solid is spotlighting a small war of words in the embedded world. On one side is a slew of vendors with disk-based embedded databases like Solid's -- including large, established database players like Oracle Corp. (Nasdaq: ORCL) and Sybase Inc., as well as relatively smaller ones such as Birdstep Technology ASA (Oslo: BIRD), MySQL AB, and Pervasive Software Inc. This camp touts its ability to optimize efficiency and programming options for OEMs.

On the other side is a growing number of in-memory database providers who say there's no reason to use disk memory to store data in embedded systems anymore, given RAM price reductions and performance gains. In this camp are the other established database vendors, as well as the likes of McObject LLC, OSE Systems, TimesTen, and Xcelerix Corp.

This "in-memory" camp says there's no place for databases (like Solid's) that claim to straddle the disk and RAM worlds. "The approaches are fundamentally different; you can't do both at the same time well," says Steven T. Graves, CEO and cofounder of McObject. He says router information is by nature so transient that it's best handled in RAM.

"Older databases were designed for disk prior to availability of cheap RAM," says Tim Shetler, VP of marketing at TimesTen. If you have access to plentiful cheap RAM, he maintains, why not go for the faster performance? He scoffs at the idea that Solid might be a competitor, or that there would ever be a need for his products to support disk storage.

Arguments like these don't carry weight with Solid. "Many of our customers make consumer devices, and they don't think RAM is cheap," says Solid's Colton. To gain access to information in memory, he says, often requires double the RAM to perform the retrieval. Further, a lot of embedded applications don't need faster performance, so the need for in-memory databases isn't necessarily a given.

And so the flap goes, each side claiming to have the goods on embedded systems. Unless you're a developer with firsthand knowledge, it's tough to take a side.

Indeed, leading vendors seem to be using a mixed bag of these products. Like Solid, for instance, TimesTen claims Avaya Inc. (NYSE: AV) and Hewlett-Packard Co. (NYSE: HPQ) as customers. It's also got Cisco Systems Inc. (Nasdaq: CSCO) on its list. So does MySQL, which also counts Lucent Technologies Inc. (NYSE: LU) as a customer.

Perhaps the point is to have a tool to fit every embedded job. One analyst says options are key to creating embedded systems. "The whole watchword is flexibility -- programmatic and runtime flexibility," says Joshua Greenbaum, principal of Enterprise Applications Consulting. In the end, product developers will choose embedded wares that give their particular products the most ability to run without operator intervention, he says. For some, that will mean opting for technology that puts "hot" and "cold" data in different storage locations on the same device.

— Mary Jander, Senior Editor, Light Reading