username9843/airport-mis

Purpose and Execution

PostgreSQL database project for Ercan Airport (LCEN) management information. The repository is SQL-first, with no application runtime: create a PostgreSQL database and execute the scripts in sequence:

1. 01_ddl.sql — schema and database behavior

2. 02_dml.sql — seed/sample operational data

3. 03_queries.sql — management reporting queries

README.md defines this execution order; REPORT.md is the supporting design/report artifact.

Schema and Integrity Layer

01_ddl.sql is the system’s primary architectural boundary. It creates the relational model for airport operations, including tables, keys, constraints, and a trigger. This layer owns canonical data structure and enforces business/data integrity inside PostgreSQL rather than in an external service.

Paths:

• 01_ddl.sql

• REPORT.md

Operational Data Domain

The schema represents airport-management entities and their relationships, with the report providing the ERD/design context. Core operational records are stored in PostgreSQL and linked through relational constraints established by the DDL.

The database is the sole material runtime and persistence boundary; there are no indicated APIs, UI services, queues, or external integrations.

Paths:

• 01_ddl.sql

• REPORT.md

Seed and Demonstration Data

02_dml.sql populates the schema with sample data after tables and constraints exist. It is intended for reproducible demonstrations and for supplying the reporting layer with representative operational records.

The DML script depends on successful execution of 01_ddl.sql; its inserts must conform to the DDL’s relationships and trigger behavior.

Paths:

• 02_dml.sql

• 01_ddl.sql

Reporting and Management Queries

03_queries.sql is the read/reporting stage. It contains 15 management queries over the populated operational schema, producing decision-support views directly from PostgreSQL.

This script depends on both prior stages: schema objects from 01_ddl.sql and available records from 02_dml.sql.

Paths:

• 03_queries.sql

• 02_dml.sql

• 01_ddl.sql

Primary Control and Data Flow

Control flow is linear and manual or SQL-client-driven:

01_ddl.sql → 02_dml.sql → 03_queries.sql

Data flow follows the same direction: DDL defines valid structures and database-side enforcement; DML writes sample airport data; queries join, filter, aggregate, and present that data for management use. The trigger in 01_ddl.sql is an important write-time control boundary because it can apply behavior automatically during data changes.

Infrastructure Boundaries

Required infrastructure is a PostgreSQL server and a database created by the operator. SQL execution tooling is external to the repository (for example, psql or a PostgreSQL GUI), and no deployment automation or application host is represented.

Paths:

• README.md

• 01_ddl.sql

• 03_queries.sql