Contents:

• Year 2000 Readiness Disclosure
• The Year 2000 Problem
• The Sirius Solution
• Converting YY to YYYY - CENTSPAN
• Improved Formats for Date Values
• Sir2000 User Language Tools
• Sir2000 Database Analysis Tools
• Sir2000 Field Migration Facility
• Millennium Extensions to Other Sirius Products

The Year 2000 Problem

The rapid approach of the twenty-first century is a cause of concern for all data processing shops. While the actual scope of problems caused by the millennium rollover will vary from company to company and even by application, the potential exposure is enormous. The year 2000 crisis is fueled by a variety of factors:

• Data elements containing dates have been stored in a variety of formats that only maintain two digits for the year value, e.g. "52" instead of "1952". The motivation for storing only the least significant two digits of a year value was to save storage space. A recent study suggests that for most companies the historical savings from storing two-digit year values are substantially greater than the expected expenditures for year 2000 projects!

  Date values containing only two-digit years cause no problems as long as all dates are from the same century. "96" is greater than "75", and the difference is clearly 21 years. When dates from different centuries are mixed, simple relationships break down. When the year 2001 is represented as "01", it will compare as less than the year 1996 represented as "96". The difference between the two will be -95 instead of +5. This problem is especially pronounced for Model 204 because there is no standard format for date values, which are typically stored as character strings.

• Mission critical legacy applications at the core of most businesses have proven to be surpisingly durable and costly to replace. As a result many applications that were scheduled to be replaced before 1999 are now expected to remain active well into the next century. Shops that retooled for application conversions are now scrambling to rebuild expertise in their legacy systems.
• The quantity of data containing date values with two-digit years is enormous and growing steadily. Significant resources will be required to reorganize the data, converting two-digit year values into the correct four-digit year values.
• The deadline for year 2000 compliance is rigid. Although many projects will no doubt spill over into the next century, all mission critical systems must be at least year 2000 tolerant by the end of 1999.

There are two fundamental schools of thought on how to achieve year 2000 compliance with Model 204 applications. One approach leaves the databases as they are, presumably with a mixture of two-digit and four-digit year values, and confines all changes to the application logic. The alternative champions converting all date fields to a format that includes four digits for each year value, and then making any required changes to the application code.

Proponents of the first approach argue that it allows the coexistence of unmodified old applications with the new year 2000 compliant versions under development and that it requires fewer resources to implement. The basis for these claims is the assumption that the underlying databases will not require reorganization. Proponents of the database-centric second approach maintain that while it might require more steps, it provides a framework for managing a a year 2000 project that is amenable to automation and that the resulting applications and databases are more robust. In addition the trend towards warehousing increasing amounts of historical data argues for consistent representations of data elements that contain dates.

The first approach employs various techniques to map the two-digit year values contained in the databases into a contiguous 100 year range in the full space of four-digit year values. While storing dates with two digit year values may work in many cases, there are a variety of common cases that will require four-digit year values when the date values span a century boundary:

• sorting records based upon date values,
• performing a range retrieval using a date field, or
• when the values stored for a date field span more than 100 years.

Sirius believes that the database-centric approach is superior, especially when coupled with specialized support tools. It provides a natural framework for project management and produces robust applications and databases, providing a solid foundation for future applications.

Sir2000 - the Sirius Millennium Solution

Sir2000 comprises an improved method for converting two-digit year values to four-digit year values, new and improved formats for date values, and three separately packaged product sets.

In addition, all Sirius products are year 2000 ready and several products have been enhanced to address specific aspects of the year 2000 problem. Sir2000 supports all popular releases of Model 204, including Version 2.2, Version 3.1, Version 3.2.1 and Version 4.1.

Improved Conversion from YY to YYYY - CENTSPAN

A date field with only two digits for the year value is capable of representing a range of one hundred years. When we compare a pair of two-digit year values we are accustomed to thinking of the century as fixed, so that all dates are either "19xx" or "20xx". A date field with two-digit year values can contain dates from two different centuries, provided that the range of dates does not exceed 100 years.

CENTSPAN provides a mechanism for unambiguously converting dates with two-digit year values into dates with four-digit year values. The CENTSPAN mechanism allows two-digit year values to span two centuries without confusion. CENTSPAN identifies the four-digit year value that is the start of the 100 year span represented by the two-digit year values.

CENTSPAN may be specified as an absolute unsigned four digit value between 1753 and 9999, or it may be specified as a relative signed value between -100 and +100, inclusive. A relative CENTSPAN value is dynamically converted to an effective absolute value each time it is needed to perform a YY to YYYY conversion. The effective CENTSPAN value is formed by adding the relative CENTSPAN to the current four-digit year value at the time of reference.

A simple algorithm is used to convert a two-digit year value (YY) to a four-digit year value, using a four-digit absolute or effective CENTSPAN value (HHLL). If the two-digit year value is less than the low-order two digits of the CENTSPAN value, then the resulting century is one greater than the high-order two digits of the CENTSPAN value. Otherwise the resulting century is the same as the high-order two digits of the CENTSPAN value.

Relative CENTSPAN settings provide a powerful tool for accomodating the gradual migration from date values with two-digit years to date values with four-digit years. Applications can be coded with a fixed value, for example CENTSPAN=-75, and the 100 year window of dates slowly slides from 1922 forward. As long as there are no date values older than 1935 for a particular field, CENTSPAN=-75 can accomodate two-digit year values until 2010 or beyond.

New and Improved Formats for Date Values

Sir2000 User Language Tools

Sir2000 User Language Tools includes the following components:

• APPDATE command allows individual programmers to independently change the date and/or time returned by the various Model 204 date dollar functions. Time can be moved forwards and backwards without confusing other users or the various auditing tools.
• APPDATE command and related dollar function provides a facility to trap errors within various date dollar functions, without requiring any changes to the User Language code. Greatly simplifies ad-hoc testing and debugging of existing applications.
• A powerful dollar function library precisely tailored to the various problems of storing and manipulating date and date/time values within User Language applications. Provides improved programmer productivity and readability of application code.
• SirPro Model 204 editor interface with supersearch feature to help programmers rapidly locate and rename datefields in procedures.
• SirLib to manage the many changes to User Language procedures.

Sir2000 Database Analysis Tools

• DATESTAT utility. An automatic tool for analyzing a file and determining the date fields. Provides detailed information about each identified field, including the formats and distribution of date values. Greatly simplifies the process of determining the appropriate CENTSPAN value, if any. DATESTAT is built on top of the Fast/Unload I/O routines.
• SirDBA, which is the JANCAT file exploration and mapping utility from the Janus OMNI SQL Server, packaged as a standalone product. This provides the ability to analyze a Model 204 file and automatically determine its structure. SirDBA produces a relational view of a file, after identifying record type fields, record types, and all likely date fields.
• Extensions to SirPro that provide integration with the catalog maintained by the SirDBA. For example, while viewing a SirDBA dictionary list of date fields, a single keystroke will produce a SirPro list of procedures containing the field name string.

Sir2000 Field Migration Facility

The Sir2000 Field Migration Facility makes it possible to separate the process of updating date fields to contain 4-digit years from the process of updating applications to use the 4-digit year fields.

With the Sir2000 Field Migration Facility it is a simple matter to populate Model 204 files with 4-digit year fields that correspond to existing 2-digit year fields. Since both fields are stored in the database files, applications will continue to work through 1999 with no modification. Furthermore, the Sir2000 Field Migration Facility will automatically keep the 2-digit year fields in synch with the 4-digit year fields so that any updates to either of these fields will be reflected in their corresponding 2-digit or 4-digit field. What this means is that applications can be converted to use 4-digit fields in stages rather than all at once. In fact, it is possible to only change references to the 2-digit year fields where absolutely necessary (in SORT statements, for example). Sir2000 Field Migration Facility simplifies the process of managing Y2K data and code conversion and, in many cases, dramatically reduces the amount of coding required to make applications "Y2K compliant".

Provides the following functionality:

• Support for RELATE processing. Includes modifications so that the Fast/Reload correctly handles RELATEd fields, as well as User Language and IFAM2 update DML.
• Support for WARN, NOWARN, and CANCEL to allow, warn, or prevent non-enhanced load modules from accessing Model 204 files that have RELATEd fields defined.
• Support for CENTSPAN.

Millennium Extensions to Other Sirius Products

Extensions to Fast/Unload

Several extensions to Fast/Unload will assist with the high volume of file maintenance expected to accompany efforts to make Model 204 applications ready for the year 2000. FUEL extensions. These include support for FUEL variables, assignment statements, date manipulation and other "# functions" (the FUEL analog of $ functions), and ADD/CHANGE/DELETE field support.

Extensions to Fast/Reload

LOAD field_old AS field_new. Provides the ability for a field to be renamed during a Fast/Reload. This is especially useful during a UAI/LAI reorganization, for example to rename DOB4 to DOB. Requires the FLOD compiler feature of Fast/Reload.

The statements here are Year 2000 Readiness Disclosures.

If you are purchasing or receiving any Sirius software or service designed to detect or correct Year 2000 processing problems in systems, products or services (for example, Model 204) manufactured or rendered by another- person or entity, please note that: STATEMENTS MADE TO YOU IN THE COURSE OF THIS SALE ARE SUBJECT TO THE YEAR 2000 INFORMATION AND DISCLOSURE ACT (Public Law 105-271, 112 Stat. 2386). IN THE CASE OF A DISPUTE, THIS ACT MAY REDUCE YOUR LEGAL RIGHTS REGARDING THE USE OF ANY SUCH STATEMENTS, UNLESS OTHERWISE SPECIFIED BY YOUR CONTRACT OR TARIFF.