article just published by member of Centura management in highly regarded trade magazine by the way i have no position in Centura,yet,anyway.
<< Embedded Systems -- Focus: Consumer Computing
Wanted: small, fast database managers
Ted Kenney, Senior Marketing Manager, Centura Software Corp.,
11/08/1999
Electronic Engineering Times
Page 105
Copyright 1999 CMP Publications Inc.
Seattle#
Databases for Net-centric devices must offer the scalability and
extensibility lacking in self-developed data-management solutions while
demanding little in terms of RAM, CPU and disk storage footprint, and
administration requirements. Providing a new frontier in data
management, such applications include office hardware,
telecommunications devices, consumer devices and Internet appliances.
Four forces are at work here. First is economics. Prices of RAM, CPU
cycles and disk storage are declining. Although companies developing
devices-particularly price-sensitive products for mass distribution-still
seek to minimize resource requirements, there is no doubt that dropping
prices have eased the footprint restrictions that previously ruled out the
use of a database.
Second is standardization. The coalescence of the embedded systems
market around real-time operating system platforms such as Wind River
Systems' VxWorks has allowed database vendors to offer their products
profitably in this market segment.
Third is market demand. Consumers want intelligent full-featured devices,
and a prerequisite is the ability to manage more data and more complex
data relationships.
Fourth, and perhaps the most important, is the Internet, a factor that is
reshaping the development of devices. It is also a potent, albeit less
recognized, force in devices' adoption of database management system
(DBMS) technology. This is true for several reasons, among them that
communications is a critical requirement for many kinds of devices
(mobile phones and set-top boxes, for example) and a beneficial one for
many others (personal digital assistants and office equipment). With the
Internet emerging as the most significant global communications medium,
devices must hook in.
But why a database? Behind the demand is the fact that the Net itself
presents an ever-expanding data set, with every node representing a point
or points of data and every grouping of nodes presenting a simple or
complex data relationship. All applications (including devices), whatever
their function, must model or reflect some targeted real-world data. When
that set crosses a threshold of size or complexity, applications require the
abilities of a full-featured DBMS.
To illustrate the way in which the Internet is driving database adoption in
such devices, it is instructive to look at a number of specific applications:
an Internet-enabled device from Hewlett-Packard Co., an Internet
infrastructure device from NetMoves (Edison, N.J.) and an
Internet-enabled set-top box from Hughes Network Systems.
With HP's 9100C Digital Sender, an office communications device,
documents are fed into the device, which digitizes them and sends them to
any e-mail address. Documents can also be sent as faxes, to networked
printers and to various networked applications, but being able to e-mail a
document anywhere on the Internet is the feature HP promotes most
heavily.
The new e-mail and Net focus of the 9100C required management of
some 700,000 data points, along with complex data relationships, largely
to support public and private e-mail address books but also for
configuration and logging. Preceding technology used a self-developed
solution based on flat operating system files to manage data. Developers
of the 9100C were hesitant to use that solution because flat files tend to
fail when required to scale up to handle larger volumes of data, and
scaling up was clearly a requirement of the 9100C's data management.
In addition, a homegrown solution based on flat files usually lacks
extensibility. That is, it suffices for a specific task but falls down when
applied to other tasks. HP developers believed that developing the
9100C around the flat-file data-management solution would require
unacceptable amounts of development and QA time.
HP chose to use the Raima Database Manager for VxWorks (RDM/Vx)
cross-platform DBMS. For retrieval performance, RDM/Vx fit the
requirements for several reasons. First, RDM/Vx is built around a C
function library, which meshed with the chosen tool, C/C++.
Many databases require the application to talk to the data-management
component through a Structured Query Language (SQL) interface; in this
project, SQL would have added an unnecessary layer that could hinder
performance.
Also, while most DBMS now support the relational database model,
what was needed was a database that supported both the relational
model and the pointer-based network database model. Although the
relational database model, based on indexed access to records, provides
some advantages in flexibility, the network model can provide significantly
better performance because records are physically linked and accessed
directly.
As for NetMoves, its Internet Fax Processing Switch (IFPS) is an
example of the growing data management needs of Internet infrastructure
devices. Faxes can be sent via NetMoves in two ways. First, an
individual can attach a file to an e-mail and send it; second, a fax can be
sent from a home or office fax machine.
In either case, the information-the fax or e-mail, along with data about the
sender-arrives at the nearest IFPS. That triggers intensive data processing
on the switch as information is sought on sender verification and
privileges, preferred formatting and routing. Logging and billing
information is stored as well. Other necessary processes, such as
conversion of an e-mailed Word document to a bit image, are not as
data-access-intensive.
When the document is processed, it is routed over the Internet to the
IFPS nearest to the fax' destination. It is then routed off the Internet and
into the local telephone network, and it arrives at the recipient's fax
machine as a normal faxed document.
Although the device must process and route faxes quickly, it does not
necessarily require the instant response expected in a consumer or office
device. NetMoves wanted to use SQL as the database interface
language. The SQL API may entail some processing overhead, but it was
preferred because of its ease of use and because the language is familiar
industry wide. An additional level of complexity was that NetMoves
planned to develop products on both UnixWare and Solaris.
For a cross-platform SQL client/ server DBMS, NetMoves chose the
Velocis Database Server. It is available on Windows NT and on most
flavors of Unix, including Linux, Solaris, SCO and UnixWare. While
Velocis offers the same choice of application programming interfaces and
database models found in the RDM database, NetMoves achieved the
needed results-and found the desired familiarity-in the SQL interface.
Velocis' zero-administration capabilities-which allow developers to
automate administra- tive and maintenance features-were also an
important reason for the selection.
Hughes Network Systems has incorporated the Raima Database
Manager for VxWorks into a new set-top box that is going to be used
with the AOLTV and DirecTV services. Used as the basis for a
content-rich interactive programming guide, the database will play a role
in letting users manage the array of choices made possible by the
convergence of television, broadband and the Web.
Many interactive services could benefit from client-side applications that
link to an embedded database for complex data-management tasks.
Another benefit of a local database in various Net-centric devices might
be to provide a local cache of Internet data for quicker retrieval.
November 08, 1999 >> |
