• Snow couldn't keep 'em away from User Group meeting
• System 1032 Technical Note: RANGE is "a good thing"
• Top ten reasons to join your colleagues at IMPACT'97
• RCL Feature in Model 204 V4R1 and Connect* V2.0

Snow couldn't keep 'em away from User Group meeting

by Gina Scinta

The first snow of the year for Washington, D.C. was not enough to keep Model 204 users from attending the 12th annual Washington User Group meeting held at the Sheraton Woodley Park in Washington, D.C. The theme for the conference was "Changes in the Next Millennium."

Rick Ryan, President of CCA, kicked off the meeting with an overview of CCA Corporate Status. Rick reinforced CCA's commitment to developing long-term relationships with the customer base and support for high-performance, open access to Model 204.

Chris Ramsdale, Director of Marketing, followed with CCA's Product Plan, which includes increased development of "Open Connectivity" features such as SQL and Connect*, utilizing the World Wide Web, working with users to identify performance enhancements, as well as enhancements to DBMS/4GL.

The hot topic of the day was the Year 2000 issues. Keynote speaker, Jim Damon, discussed Year 2000 issues for Model 204 files and applications, and presented the Model 204 V4R1 functions and parameters to enable testing in Year 2000 Mode.

The afternoon breakout sessions included Gina Scinta's presentation of CCA connectivity offerings using Dominion Empower and Connect*, Jim Damon's trends in Model 204 performance, and Sirius' presentations of SIR2000 and the Janus Web Server.

Over 40 attendees from 16 Model 204 accounts were present for the user group meeting. The attendees felt that the conference met or exceeded their expectations.

The user group held elections for 3 open WUG board positions. Charlie Arehart was elected President, Steve Smith was elected Vice President, and Diane Rodriguez was elected Secretary.

CCA hosted a reception following the meeting.

System 1032 Technical Note:

by Tym Stegner

The RANGE option of an attribute definition lets you define a set of delimited values for numeric or date-time attributes. You can specify the minimum or maximum, or earliest-to-latest acceptable values. This not only protects your data from silly errors (computer software engineers born in 1852), but also it often lowers the amount of storage space the attribute uses in the internal dataset record.

Reducing storage space

Consider the following dataset definition, CALLTRACK, which is used for tracking telephone calls:

Dataset CALLTRACK
Attribute CALLNB Integer Format I,6
Attribute CALLER Text 35
Attribute CALLDT Date_Time Precision Minutes Format D3YY.3
Attribute PRIORITY Integer Format I1
Attribute OPERATOR User of Entry

This dataset, as defined, has an internal record length of 63 bytes, or 504 bits, to accommodate the default ranges. Default ranges include all possible values for the data type, including both positive and negative numbers out to the default precision limit. The 63 bytes include 4 bytes each for the integers, 8 bytes for the date-time, 12 bytes for the user-of-entry, and 35 bytes for the fixed text.

Redefining the dataset with ranges

If you define ranges for the appropriate attributes, based on your knowledge of the data involved, you can reduce the amount of space needed for those attributes.

In the case of the CALLTRACK dataset, for
example:

• Call numbers (CALLNB) are always positive, and you expect to attain fewer than a hundred thousand calls over the life of the dataset.
• You do not track any calls older than this year (CALLDT).
• The PRIORITY attribute has only 4 values: 1 through 4.

Armed with this information, you apply ranges to the dataset as follows:

Dataset CALLTRACK
Attribute CALLNB Integer Range 1:99999 Format I,6
Attribute CALLER Text 35
Attribute CALLDT Date_Time Range '1/1/1997':'1/1/2017' Precision Minutes Format D3YY.3
Attribute PRIORITY Integer Range 1:4 Format I1
Attribute OPERATOR User of Entry

The newly defined dataset has an internal record length of 51 bytes. This includes 16 bits for CALLNB, 35 bytes for CALLER, 23 bits for CALLDT, 3 bits for PRIORITY, and 12 bytes for OPERATOR. The new internal record is 19% smaller than before.

Enter the RANGE bit mask

When range is defined for an attribute, System 1032 no longer stores an actual value for the attribute. Instead, it stores a bit mask whose length is the number of bits necessary to count the values in the range. The value is stored by setting the bits to indicate which value within the range is being stored. For example:

• The PRIORITY attribute as a standard integer value takes 4 bytes, or 32 bits. But with a range defined, only 4 acceptable values can be stored: 1-4. This number of values (4) is counted in binary using only 3 bits.
• In a similar fashion, the number of possible values for CALLDT is 10,519,200; calculated by subtracting the lower boundary of the range from the upper boundary, and dividing by the precision of the data being stored:

('1/1/2017'-'1/1/1997')/1 minute

These values can be expressed using only 23 bits, instead of the 64 bits necessary for the full 8-byte value.

System 1032 arranges the attributes internally to pack the resulting value masks as tightly as possible. Therefore, the actual internal record might be slightly larger than calculated.

For this simple example, using attribute ranges has saved about 20% of the space in the record. For a more complex dataset with many more records, these savings can be further improved.

Special Considerations

The RANGE option applies only to numeric and date-time attributes.

You cannot dynamically modify range information, because it is part of the dataset definition. You must change the definition and rebuild the dataset to modify range information.

1. Learn how the Internet, the Web, and Intranets can increase your options to meet critical business needs as new technologies, legacy systems, tight budgets, and intensified user demands stretch IT departments beyond available resources.
2. The Year 2000! Time is running out with regard to the methodologies and processes that companies need to employ to meet the new millennium. Hear what you need to consider regarding these changes and return to your offices ready to apply what you learn to your systems.
3. Hear an update from CCA senior management on company status, direction, and product strategies, and how these will benefit your organization. CCA will present its new corporate strategy that resulted from the numerous survey returns and regional meetings held over the last year.
4. Learn how industry specialists, vendors, and other users address the same real-world issues that you face.
5. Attend CCA sessions covering both Model 204 and System 1032 and learn about new features and functionality.
6. Get the best answers to your toughest Model 204 and System 1032 questions at the "stump the experts" Guru Session.
7. Hear about ways to enhance the benefits you receive from CCA products through performance and tuning, and new releases of products -- including Empower, MP/204, and for Model 204 and a new and improved ODBC for System 1032-- that address parallel processing, client/server computing, and Internet--Intranet--Web access.
8. See in-depth demonstrations of CCA products and learn how you can use them to benefit your organization.
9. Provide direct input to CCA to influence product direction and ensure that your evolving requirements are served. Through informal conversations with CCA representatives and your vote at IMPACT'97, you can help build the CCA User Group product-development wish list.
10. IMPACT still provides the greatest educational value for your dollar. By combining industry experts, courses, demonstrations, and interaction with vendors and other users -- all in one place -- IMPACT will sharpen your skills and improve your ability to contribute to your organization.

For details about the IMPACT'97 conference call the IMPACT office at 617-595-2005.

Figure 1: Client/server model

The new Remote Command Line (RCL) facility will be delivered with Model 204, V4R1 commercial release on June 30, 1997. Its true power goes far further than the name RCL may lead you to believe. With the RCL facility, clients within a Windows application can now pass Model 204 commands, User Language procedures, or APSY subsystem names, to an Online. All User Language commands are available with the exception of those that generate full-screen I/O, such as INCLUDE PROC.READ.SCREEN. Also, one Model 204 command, EOJ, is not allowed from an RCL thread. You can create a procedure on the PC using your editor of choice, upload it to Model 204, store it, and then run it from within a Windows application that uses CLI or ODBC calls. The existing Model 204 SQL client/server model illustrated in Figure 1 is used. Here at CCA we wrote a simple RCL application that has already been of great use. Our Problem Determination System (PDS) logs calls from customers, notes progress on diagnostics and error messages, and records correspondence between CCA and the user. It is a basic 3270 application. As you might imagine, the records on complex calls spread over 25 to 50 screens of information. The usual page up/page down scrolling method is tedious. But with our simple RCL application, all the information from a selected call can be immediately downloaded into a PC text file, so that all the helpful PC facilities like cut-and-paste and full scroll bars can be used. Future editions of CCAPRINT will provide further details about RCL. In the meantime, customers in our beta test program can try it for themselves.

 

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