Know and understand characteristics, uses, advantages and disadvantages of a flat file and a relational database

Topic 18 – Databases

Objective

Know and understand the characteristics, uses, advantages and disadvantages of a flat‑file database and a relational database.

1. Flat‑File Database

Characteristics

• Data stored in a single plain‑text file (often CS \cdot or fixed‑width).
• Each line represents one record; fields are separated by delimiters such as commas or tabs.
• No built‑in relationships between different files.
• Simple structure – essentially a two‑dimensional table.

Typical Uses

• Small‑scale applications where only a few hundred records are needed.
• Import/export of data between different programs (e.g., spreadsheets, simple accounting packages).
• Log files, configuration files, and temporary data storage.

Advantages

• Easy to create and edit with any text editor.
• Low overhead – requires minimal storage and processing power.
• Portable – can be moved between different operating systems without compatibility issues.

Disadvantages

• Limited ability to handle large volumes of data; performance degrades quickly.
• No support for data integrity rules (e.g., primary keys, foreign keys).
• Redundant data is common, leading to inconsistency.
• Searching, sorting and reporting are manual or require external tools.

2. Relational Database

Characteristics

• Data stored in multiple related tables, each with rows (records) and columns (fields).
• Uses Structured Query Language (SQL) for data definition, manipulation and retrieval.
• Enforces data integrity through primary keys, foreign keys, and constraints.
• Supports relationships: one‑to‑one, one‑to‑many, many‑to‑many.

Typical Uses

• Business applications (inventory, sales, payroll, customer relationship management).
• Web applications that require dynamic data handling.
• Educational and research databases with complex queries.
• Any situation where data consistency, security and scalability are important.

Advantages

• Efficient handling of large data sets; queries are optimized.
• Data redundancy is reduced through normalization.
• Strong data integrity and consistency enforced by constraints.
• Multi‑user access with transaction control (ACID properties).
• Powerful reporting and analysis capabilities.

Disadvantages

• More complex to design, implement and maintain.
• Requires dedicated DBMS software and hardware resources.
• Steeper learning curve for users unfamiliar with SQL.
• Initial setup time and cost can be higher than flat‑file solutions.

3. Comparison of Flat‑File and Relational Databases

4. Summary

Flat‑file databases are straightforward, low‑cost solutions ideal for very small or temporary data storage, but they lack the robustness required for larger, multi‑user environments. Relational databases, while more complex and resource‑intensive, provide powerful tools for maintaining data integrity, handling large volumes of information, and supporting sophisticated queries. Understanding the strengths and limitations of each type enables ICT practitioners to select the most appropriate system for a given application.