ACS Reference Requirements

by Jon Griffin

I. Introduction

This document describes the requirements for the ACS Reference service package. This package has the following primary functions:

II. Vision Statement

What is reference data? Simply put, it is data that doesn't change very often and also in many cases comes from an external source and not from within the system itself. Many times it is created from a standards body, i.e. ISO or ANSI, and may be required for a client's particular industrial needs.

Some examples of reference data are:

Historically, reference data has been looked upon by developers as something less important than more immediate coding needs, and so most data models simply defer the issue by treating reference data as something simple to implement. Elsewhere. The reality is that for most organizations reference data is extremely important and also extremely difficult to manage.

This module will not only package all of a site's reference data in one place, it will also help manage that data.

III. System Overview

The ACS Reference package consists of:

IV. Use-cases and User-Scenarios

Papi Programmer is developing a module that will use country codes as part of his table structure. Instead of creating his own table he can use the ACS Reference package and the country codes therein. If the country codes change - which does in fact happen from time to time - the ACS Reference package will maintain that information for him.

V. Related Links

VI.A Requirements: Data Model

10.10 The package should use a table that is the master table for all reference tables.
10.20 The package should employ a field to show whether this data is internally derived or not.
10.30 The package should employ a field to signify whether there is a PL/SQL package involved with this table.
10.40 The package should offer an indicatation of when this data was last updated.
10.50 The package should offer an indication of what the original source of this data was.
10.60 The package should offer an indication of what the original source URL was, if any.
10.70 The package should offer a representation of effective datetime
10.80 The package should offer a representation of discontinued datetime
10.90 The package should keep an indication of who the data maintainer is, by user_id.

VI.B Requirements: API

20.10 The package should offer a function to determine if a particular table has expired.

The requirements below are not met by the current implementation:

30.10 There needs to be a way to query the data source and update automatically. If that isn't possible, as it won't be in many cases, the application should be able to query a master server and see if there is new data for a particular table or tables. For example: could hold the reference tables and when newer table versions become available, simply upload only these versions or perhaps even only the differences between the tables. In any case, there should be an admin page that shows current status and revisions of various data, where to find info about additional sources (if applicable), and provide a UI to upload or import new data.

VII. Implementation Notes

The package needs to handle changes to reference data in a graceful fashion. For example, if a country splits into two or more countries, what should happen?

Note also that it is possible to have overlapping effective dates. This will not be implemented in the first version, but should be recognized and accommodated throughout the development process for the service package.