If your corporate databases run on diverse platforms distributed throughout your organization, you probably have to set up and maintain Open Database Connectivity (ODBC) data sources and database drivers so that your users can access your databases. You need ISG Navigator from International Software Group.

ISG Navigator is a middleware application that uses Object Linking and Embedding (OLE) to consolidate access to different databases under a common ODBC data source. Using ISG Navigator, you can access Oracle, Sybase, SQL Server, and Jet databases that run on various platforms, including Windows NT Server, MVS, HP UNIX, OpenVMS, Advanced Interactive Executive (AIX), and Solaris. Users can access the data source through any ODBC-compliant application, including Microsoft Access and Visual Basic (VB).

Installing and running ISG Navigator require intermediate-to-expert knowledge of database administration. However, multiplatform and distributed database developers, ISG Navigator's target customers, are unlikely to have problems using the product.

The Installation
To install ISG Navigator, you first need to install the software on your NT host by running the nav1127w.exe program that comes on the software's distribution CD-ROM. When the system finishes copying files, you must set up two ISG Navigator files--a bindings file and a security file--for every collection of distributed databases you plan to group together.

The bindings file must contain a list of the machine names, remote data source names, and driver types that ISG Navigator needs to access remote databases. (The product accesses every database through a remote connection, even if the database resides locally.) ISG Navigator bindings files are standard text files arranged in a format similar to win.ini. In the first section of the bindings file, under the heading Remote Machines, you assign mnemonic names to the remote machines you plan to access. In the second section, under the heading TDP-Names, you assign mnemonic names to the databases you plan to access. In the same section, you define each database's type and establish whether the database is remote or local. Then, you must create a bindings file section for each database you list in TDP-Names. Each section's heading is the mnemonic name you assigned the database in TDP-Names. Under the heading, you define driver-specific parameters that the ISG Navigator software needs to attach to your data source. Screen 1 shows a sample bindings file. Setting up the bindings file can get complicated, and you might have to spend quite a bit of time debugging your first bindings file.

ISG Navigator's security files are more basic. They contain the username and password that the ISG Navigator engine will need to access each database. The only problem I found with this product is that you write the security files in plain text, so they might present a security risk.

The Tests
For my testing, I used ISG Navigator to access three databases: a SQL Server database on my NT server, an Oracle database on my SCO server, and an Access database on my NT workstation. After setting up my bindings and security files, I created my ODBC data source, which I named MyDB. Using the ODBC Manager, I specified ISG Navigator as MyDB's ODBC driver. I used Access 97 to access MyDB. When I launched Access 97, I selected link tables, specified MyDB as my ODBC data source, and received a list of tables to attach. After attaching tables in all three databases, I browsed their contents.

I did a series of retrievals through MyDB and found performance with ISG Navigator to be comparable to the performance of typical ODBC data sources, although ISG Navigator retrievals were slightly slower (not surprising considering the extra overhead). For example, a record retrieval that took 35 seconds when I used a pass-through SQL query took 37 seconds when I used ISG Navigator. This performance sacrifice is a small price to pay for the significant benefits of ODBC data source consolidation and distributed platform accessibility.

ISG Navigator
Contact: International Software Group * 781-221-1450, Web: http://www.isgsoft.com, Email: info@isgsoft.com
Price: $200 per user (plus server licenses needed for platform-dependent database communications)
System Requirements: Windows NT Server 3.51 or 4.0, Windows 95, UNIX, OpenVMS or MVS, 16MB of RAM (32MB recommended), 12MB of hard disk space