If you are building an Internet information store, Cognos' DataMerchant may help you speed up your development process. This software provides a quick and easy way to organise your data for sale, configure data-access control, and construct a storefront.
There is no online billing software included in DataMerchant; however, it was able to integrate with key Internet-commerce products, such as Verifone's vPos, Microsoft's Site Server, or CyberCash's CashRegister.
Despite its strengths, this is DataMerchant's 1.0 release, so some features, such as productivity tools and team development features, are still missing.
Wholesale or retail sales
DataMerchant provides two data selling models: wholesale and retail. The wholesale model allows consumers to subscribe to part- icular data by paying a subscrip-tion fee. With this model, customers are able to link their ODBC-aware applications (such as report writers or Visual Basic applications) to DataMerchant's data stores using live ODBC connections via the Internet.
With the retail model, data can be delivered as HTML pages or as a file that can be imported into spreadsheet applications for local analysis.
Unlike the wholesale model, the retail model requires no DataMerchant client software.
Instead, only a Web browser is needed on customers' PCs or workstations.
There are three major components within DataMerchant -- DataMerchant Server, Storefront Server, and DataMerchant Direct. All of the components except the client software run on Windows NT Server using TCP/IP networking.
In order to protect your data, firewall integration is provided under DataMerchant.
With the retail model, a Web server is also required. Unfortunately, DataMerchant only works with Web servers that support Netscape Server API (NSAPI) and Internet Server API (ISAPI); it also requires that the Web server support HTML 3.2 or later.
Setting up the server
DataMerchant Server is the centre of this product -- it is the only component that actually connects to the back-end databases (through ODBC drivers). It also controls data access and pricing.
By creating DataGates and DataServices under the DataMerchant Server Administrator, I was able to define which data tables would be visible to the consumer, specify stored procedures, set up data access limitations such as row retrieval limitations and inactivity time-outs, and outline billing methods for consumer groups.
However, one flaw I found is there is no way to prevent retail consumers from using hidden tables or stored procedures in their SQL statements. In other words, consumers may be able to access data that they are not authorised to access, if they learn the names of these tables and procedures.
One solution for blocking retail consumers from accessing hidden tables or stored procedures is to block them from constructing SQL statements altogether, thus limiting them to clicking on prefabricated queries you provide.
Consumer accounts are also defined and managed by Data-Merchant Server. Every consumer needs a valid account to access data and is charged based on their account activities.
I liked the fact that I was able to activate or deactivate an account by simply pointing and clicking.
DataMerchant also allowed me to create queries for particular accounts based on their access rights. Unfortunately, it was annoying that no table structure view was provided during query construction. Instead of simply browsing the data structure, I had to memorise all my field and table names while creating a query -- a serious limitation with large data structures that may contain hundreds of tables and field names. Furthermore, I was not able to test these queries inside DataMerchant Server Administrator.
Opening the data store
Storefront Server provides everything that is required to sell data via the Web. It connects with the DataMerchant Server through ODBC drivers and interacts with the Web server using ISAPI or NSAPI. Storefront Server can be located at the same site as DataMerchant Server, or at any remote site on the Net. If Storefront Server is installed remotely, the DataMerchant Direct server and client are used for communication between the StoreFront Server and DataMerchant Server.
Consumers enter DataMerchant's storefronts using a Web browser to manage their account information, select their billing methods and define what they want to buy and how they want it delivered.
To simplify shopping for data, Storefront Server offers Shopping Assistants -- a series of user-friendly HTML pages that customers can use to build queries. It can only be used by retail consumers (those who use a Web browser). Both storefronts and Shopping Assistants are created and managed by Data-Merchant's Storefront Studio component. Wizards are provided for creating storefronts and Shopping Assistants.
Creating a storefront is straightforward.
Simply by pointing and clicking, I was able to create one in 10 minutes.
Storefront Studio's wizards have default HTML page templates for storefronts, but it is possible to add your own HTML page templates.
Unlike creating storefronts, developing Shopping Assistants is a bit tricky and tedious. It would be very difficult for anyone without knowledge of HTML syntax. Even though the Shopping Assistant wizard generates HTML pages based on DataServices. I still had to modify those pages in order to create a truly user-friendly environment for consumers.
Cognos' DataMerchant is a promising product for developing data sharing environments on the Web or over the Internet.
Anybody with basic knowledge of HTML and SQL syntax is able to use it to develop online data storefronts.
The best aspect of the product is that it allows you to open an online data store in a short time, due to its easy-to-use development environment.
DataMerchant is a great tool for setting up a business that sells data online, or for sharing information inside a corporation or among business partners over the Web.
Pros: Ease of use; support for any data format with ODBC drivers; allows live ODBC connections over the InternetCons: Works only with Web servers that support Netscape Server API or Internet Server API; no field-level access control; no capability for testing queries inside development environment; servers run only on Microsoft NT ServerPlatforms: Windows NT 4.0Price: $108,000 RRP per serverCognosTel (02) 9437 6655Fax (02) 9438 1641 www.cognos.com