XMLMap on Computing (3/4) - exploring XML
XMLMap on Computing
Non-computer devices like mobile phones and personal digital assistants (PDAs) are another area where XML's cross-platform capabilities shines.
SyncML is the open standard that drives data mobility by establishing a common language for communications between devices, applications and networks. The foundation of the SyncML open standard, SyncML Data Sync (SyncML DS) ensures a consistent data set that's always available on any device or application at any time. SyncML Device Management (SyncML DM) enables OTA administration of devices and applications, simplifying configuration, updates and support.
Sponsored by most major phone and PDA manufacturers, and supported by leading wireless companies the SyncML initiative accelerates the development and market success of SyncML DS and SyncML DM technologies.
The UPnP architecture defines common protocols and procedures to guarantee interoperability among network-enabled PCs, appliances, and wireless devices.
UPnP has six basic layers or functions: device addressing, device discovery, device description, action invocation, event messaging, and presentation, or human interface. UPnP is a protocol for data transmission; it does not move byte codes or use ActiveX controls. It is OS-independent but is built on various network standards. UPnP is designed to work in a peer-to-peer or ad-hoc network. Devices can use a DHCP (Dynamic Host Configuration Protocol) server or Auto IP (Internet Protocol) to automatically choose an IP address from a range of addresses.
Today, UPnP control points are available only in Windows Me systems. All standard Windows Me systems come with UPnP software, but users must install it. Intel provides a free software-development kit for creating a Linux-based control point. A network can have any number of vendor-enabled or Windows Me control points.
The UPnP Forum is an industry initiative designed to enable easy and robust connectivity among standalone devices and computers from many vendors. The UPnP Forum is open to any company wanting to participate in driving the adoption of UPnP. Companies with interests in particular device classes should become UPnP Forum members and participate in the process to design schema templates for their device classes. More than 300 companies are UPnP Forum members.
More and more data conitnuously becomes available in XML format. Databases are already the standard for storing structured data, and XML features are constantly added to these products.
As increasing amounts of information are stored, exchanged, and presented using XML, the ability to intelligently query XML data sources becomes increasingly important. One of the great strengths of XML is its flexibility in representing many different kinds of information from diverse sources. To exploit this flexibility, an XML query language must provide features for retrieving and interpreting information from these diverse sources.
XQuery is designed to be a language in which queries are concise and easily understood. It is also flexible enough to query a broad spectrum of XML information sources, including both databases and documents. The Query Working Group has identified a requirement for both a human-readable query syntax and an XML-based query syntax. XQuery is designed to meet the first of these requirements. XQuery is derived from an XML query language called Quilt, which in turn borrowed features from several other languages, including XPath 1.0, XQL, XML-QL, SQL, and OQL. XQuery Version 1.0 is an extension of XPath Version 2.0.
Interoperability has also reached the data warehousing field. The challenge is to solve the data warehouse metadata problem. Since every data management and analysis tool requires different metadata and different metadata model (known as metamodel), it's not possible to have a single metadata repository that implements a single metamodel for all the metadata in an organization. Instead, a standard is needed for interchange of warehouse metadata, hereby called Common Warehouse Metadata Interchange (CWMI), that is compliant with the Meta Object Facility and the UML notation (if a graphical notation is required)developed by the OMG (Object Management Group).
The objectives were to
- Establish an industry standard specification for common warehouse metadata interchange.
- Provide a generic mechanism that can be used to transfer a wide variety of warehouse metadata.
- Leverage existing vendor-neutral interchange mechanisms as much as possible.
Most data warehouse software implements CWMI today.
Finally instant messaging...
Produced by Michael Claßen
Created: Apr 28, 2003
Revised: Apr 28, 2003