Editing Business requirements

<span id="business-requirements-document"></span>
= Business Requirements Document =

'''Project:''' pgcobol — Prime Numbers Application<br />
'''Version:''' 1.0 (reverse-engineered)<br />
'''Date:''' 2026-03-17<br />
'''Status:''' Baseline


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<span id="purpose"></span>
== 1. Purpose ==

The system generates prime numbers and stores them in a relational database, and provides a printed report of all stored primes. It demonstrates a three-tier COBOL application architecture running on Linux against a PostgreSQL database.


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<span id="stakeholders"></span>
== 2. Stakeholders ==

{|
!width="50%"| Role
!width="50%"| Concern
|-
| Developer / operator
| Runs generation and reporting jobs from the command line
|-
| Database administrator
| Manages schema, credentials, and data retention
|-
| End user
| Receives the printed prime-number report
|}


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<span id="business-requirements"></span>
== 3. Business Requirements ==

<span id="br-01-prime-number-generation"></span>
=== BR-01 — Prime Number Generation ===

The system shall compute all prime numbers from 3 up to 999,999,999 using a trial-division algorithm and store each confirmed prime in the database.

'''Acceptance criteria:''' - Every integer stored in the primes table is a prime number. - No prime in the range 3–999,999,999 is omitted. - The sequence column records insertion order via an auto-incrementing identity.

<span id="br-02-prime-number-reporting"></span>
=== BR-02 — Prime Number Reporting ===

The system shall produce a formatted printed report listing all primes currently stored in the database.

'''Acceptance criteria:''' - Every row in the primes table appears in the report. - Rows are presented in database-cursor order (insertion order by ident). - The report is paginated with headings, column headers, and page numbers.

<span id="br-03-operational-modes"></span>
=== BR-03 — Operational Modes ===

The system shall support two mutually exclusive operational modes selectable at invocation:

{|
! Mode
! Argument
! Effect
|-
| Generate
| <code>generate</code>
| Compute primes and persist to DB
|-
| Report
| <code>report</code>
| Read DB and produce print file
|}

Any argument other than <code>generate</code> or <code>report</code> shall cause the program to log an error and terminate without processing.

<span id="br-04-audit-trail-console-logging"></span>
=== BR-04 — Audit Trail / Console Logging ===

All significant processing events (session start/stop, database connection, cursor open, fetch errors, write confirmation) shall be written to the system console in real time.

<span id="br-05-data-persistence"></span>
=== BR-05 — Data Persistence ===

Prime numbers shall be stored persistently in a PostgreSQL database so that the report can be produced independently of and after the generation run.

<span id="br-06-report-format"></span>
=== BR-06 — Report Format ===

The printed report shall: - Carry a page heading (“primes overview”) and a column header row on every page. - Present six prime entries per print line (sequence number + prime value). - Carry a page-number footing at the bottom of each page. - Be written to a line-sequential file (<code>primes.prt</code>) with 132-character records.


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<span id="constraints"></span>
== 4. Constraints ==

{|
!width="50%"| ID
!width="50%"| Constraint
|-
| C-01
| Target runtime is GnuCOBOL 4.0 on Linux.
|-
| C-02
| Database is PostgreSQL 11; connection is localhost only.
|-
| C-03
| Database credentials are currently hard-coded in the DAL program.
|-
| C-04
| The upper bound of generation is fixed at 999,999,999.
|-
| C-05
| The print file is fixed at 132 columns, 56 lines per page.
|}


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<span id="out-of-scope"></span>
== 5. Out of Scope ==

* Interactive (screen) input or output.
* Concurrent multi-user access.
* Prime generation restart / checkpoint recovery.
* Authentication or credential management.
* Scheduling or job-control integration.
<hr/>
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