Checklist can help users evaluate DB2 access tools; options include 4GLs, gateways, client/server; users weigh style, performance, report needs - IBM's DB2 relational data base software - Data Resource Management: DB2/SQL Query Management Tools - tutorial

Software Magazine, Feb, 1991 by Lori Weitz

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If you have been selected to choose a DB2 query management tool for your organization, consider a visit to your favorite local diner for guidance.

If it's your favorite, the quality of the food is no doubt excellent, and the prices reasonable. But the menu presents many possibilities. If you ask the waiter or waitress for assistance, you get even more selections and possible combinations. Once you make a decision, you can never be quite sure that you made the best choice.

Like the diner menu, the software selections to satisfy the need for DB2 query tools are many. In the diner, you might think about what kind of mood you are in. For the appropriate query tool, you will likely think about your business needs. Dividing tools into categories based on their approach may be a good start.

Numerous software vendors provide tools for accessing mainframe relational databases, such as IBM's DB2 and SQL/DS, as well as database servers on the PC, such as IBM's OS/2 Extended Edition Database Manager and the SQL Server from Microsoft Corp., Redmond, Wash. According to Buff Jones, general manager of the Database Tools Division of Candle Corporation, Houston, "The independent software vendors have produced tools that have significantly simplified end-user access to the relational databases."

Since IBM introduced DB2 in 1983, the product has gained rapid acceptance. Users can access the database through two standard interfaces to SQL: an interactive interface (DB2I) or an application programming interface (API).

However, these interfaces alone do not provide end users with easy access to the information in the databases. Users need to store, access, analyze, manipulate, control and report from their data. IBM offers easier access to its databases through the Query Management Facility (QMF).

Independent suppliers offer other approaches. For example, users can access the database via fourth-generation languages (4GLs), such as Focus from Information Builders Inc. (IBI), New York; Ramis from OnLine Software, Fort Lee, N.J.; and Nomad from Must Software, Norwalk, Conn. Or, users can access the data with products specifically built as query languages." Examples include DYL-IQ Express from Sterling Software's Dylakor Division, Chatsworth, Calif, and Decision Analyzer from Decision Technology, Princeton, N.J.

Access to relational databases is moving from non-intelligent terminals to intelligent workstations. According to Jnan Dash, manager of New Business Opportunities, IBM, Santa Teresa Laboratory, San Jose, Calif., IBM's direction is to provide a query management tool from an intelligent workstation, with the mainframe acting as a server. Access will be similar to the query manager, which comes as part of the OS/2 Extended Edition Database Manager. This interface uses Presentation Manager, windows and icons, and presents easy access to data for end users.

"IBM, from the Lidings Labs in Stockhohm, Sweden, is also developing a natural language access to its relational databases," Dash said. "Through English-language statements, queries will be generated." Dash continued, Another future direction is the move to a distributed architecture, which will allow access to relational databases running on different machines in the same query. The underlying DBMS-toDBMS connectivity must be in place before the query languages can perform queries across multiple machines.

SORTING OUT THE OPTIONS

Before selecting a query management tool, an organization must evaluate its present and future directions. A company should consider the following:

* Who needs access to the data-end users and/or programmers? How sophisticated are they.?

* What hardware is in use today? What are the company's future hardware requirements?

* What access style do users prefer-language syntax, menus, windows, icons or natural language?

* Are there any fourth-generation languages in use today for other applications? Would the 4GL also satisfy the query management tool requirements?

* Is DB2 performance a concern? How will use of a query management tool impact performance, and how should it be controlled? n Do users need to access other types of files from the same query language? Which ones? n What type of presentation style do users require-formatted reports, graphs or Lotus spreadsheets?

* Is the organization moving toward a client/server architecture or remaining with a mainframe terminal environment?

After thoroughly analyzing these issues, an organization can select the product that best suits its environment. Products broadly classified as "query management tools" may vary widely. A tool's access methodology may differ in style, platform, architecture and analytical capabilities.

ACCESS STYLE

Most products offer alternative styles to accessing data from relational databases, such as SQL Syntax, menus, prompts, natural language, windows and icons. The trend has been from syntax to menus and, more recently, to windows and icons.

The 4GLs Ramis, Focus and Nomad) all have easy-to-use interfaces. Ramis, from On-Line Software, uses the File Expert to set up access to new DB2 tables; the user never needs to see syntax. The Ramis SmartEditor provides a menu-driven help facility and a relational language called Relate.