Example: A Hypothetical Network Cartridge

This data cartridge would define the following object types:

•  Nodes—It represents any addressable element in the network.

•  Connection—It represents a link between the node. It contains information about the distance between nodes.

•  Route—It represents a path in the network and contains a collection of connections.

The cartridge uses PL/SQL or external 3GL procedures to implement the following methods:

•  FindShortestRoute (Node1, Node2) This method can be used to find the shortest route between any two specified nodes.

•  FindAllNodesReachableFrom (Node) This method can be used to find all the nodes that can be reached from a specified node.

•  FindMinimumHopRoute (Node1, Node2) This method can be used to find the path from Node1 to Node2 with the least number of nodes in between.

You can index the different object types mentioned earlier to make the processing of these methods more efficient.

This data cartridge can now be customized by different industries to suit their environments. For example, in the telecommunication industry, the datatypes can be used to model telephone networks. In the transportation industry, the datatypes can be used to model freight transport, and so on.

Sample Data Cartridges Provided by Oracle8

There are several cartridges provided by Oracle8. The next sections look at some of them.

Context Cartridge

The Context cartridge provides a GUI administration tool to configure Oracle8 in order to allow the following:

•  Full-text retrieval and advanced linguistic services

•  Automatic identification and delivery of key themes and theme summaries

•  Use text from a variety of formats such as HTML, ASCII, PDF, PowerPoint, Excel, and so on, and original formats defined externally

For single-byte languages supported by Oracle8, there are several features provided by context that can be used:

•  Exact word or phrase searching

•  Boolean operations such as and, or, not, and so on

•  Fuzzy matching

•  Wild-card searches

•  Proximity searches

•  Multilingual stemming

•  Thesaurus framework

Image Cartridge

The Image cartridge provides native image datatype support for two-dimensional images. It allows the following:

•  Format transcoding, compression, and specialized image processing

•  Queries based on intrinsic image attributes such as color, structure, and texture

•  Images stored as inline binary large objects (BLOBs), external flat files as BFILEs, or even on CD-ROMs

•  Support for image interchange formats such as BMP, CALS, GIF, PCX, JFIF, Pict, SUN Raster, TIFF, and others

•  Support for popular compression schemes such as CCITT G3/ G4, RLE, LZW, and JPEG

Time Series Cartridge

The Time Series cartridge provides the ability to manipulate time-dependent data. Some of its key features include the following:

•  Built-in calendar support; also allows user-defined calendars

•  Time series functions to allow analysis of time-series data

•  Time scaling functions to allow transformation from one time scale to another

Video Cartridge

The Video cartridge delivers audio and video using standard network technology. Some of the features of this cartridge are the following:

•  CD-quality audio

•  Intuitive controls such as PLAY, SEEK, PAUSE, and STOP

•  Multiple clients can receive full-screen, full video at the same time

•  Use of Oracle VideoMarker for video annotation and indexed playback

•  Macromedia Director and Authorware support

•  SNMP support

•  Oracle Video Client to embed OLE Custom Extension (OCX)

•  Plug-ins delivered via the Web

•  A variety of query functions such as extraction/trim, arithmetic, aggregate, boolean, dominate, and so on

Spatial Data Cartridge

This cartridge allows the efficient storage and manipulation of spatial data. Some of the features of this cartridge include the following:

•  Two-tier queries using primary and secondary filters, resulting in fast access

•  Use of “tiles” to provide spatial indexing

•  Support for domain comparison operators such as touch, overlap, inside, and disjoint

•  Support for basic geometric forms such as point and point clusters, and line and line strings

Virage Data Cartridge

This cartridge incorporates Virage’s Media Management System, which is used to manage digital media assets and their associated metadata, via the following two components:

•  Video Cataloger. Watches, listens to, and reads a video. Uses extracted information such as keyframes, audio profiles, and so on to build a storyboard index.

•  Media Manager and Browser. Searches the content from the storyboard. Manages permissions to access the asset. Version control via checkin and checkout.

Cartridge Architecture

Figure 28.1 shows the data cartridge architecture and how a data cartridge fits with the rest of the Oracle8 environment.

Figure 28.1.  The NCA architecture and how cartridges fit into it.

As seen from above, the end user communicates with the Oracle8 server via a GUI interface on the client side. The client and server communicate using the Oracle Net3 protocol. One of the processes on the server side will run the 3GL data cartridge-specific code. The server and the 3GL library code use Oracle Call Interface (OCI).