Data Model Innovations 1960s–2020s

A set of question-and-answer flashcards covering key milestones, concepts, and terminology in the evolution of database models from the 1960s to the present.

Which two database models were most common in the 1960s?

Hierarchical and network models.

How does a hierarchical database organize data?

In a tree-like structure with parent-child relationships where each child has exactly one parent.

What primary storage media in the 1960s influenced early database design?

Magnetic tapes and disks with limited capacity and processing power.

Which programming language was widely used for batch data processing in the 1960s?

COBOL (Common Business-Oriented Language).

In the network data model, how are objects and relationships represented?

As a graph of nodes (objects) and arcs (relationships) connected by pointers.

Who is considered the father of the relational database and what year did he publish his seminal paper?

Edgar F. Codd; he published "A Relational Model of Data for Large Shared Data Banks" in 1970.

Name the language that became the de-facto standard for querying and manipulating relational databases.

SQL (Structured Query Language).

List three major commercial relational database management systems (RDBMS) that arose from Codd’s model.

Oracle, IBM DB2, and Microsoft SQL Server.

Give two key advantages of the relational model over hierarchical and network models.

Data independence and flexible retrieval using primary and foreign keys.

What programming paradigm inspired object-relational and object-oriented databases in the 1980s?

Object-oriented programming (OOP).

How does an Object-Relational Database (ORDBMS) extend the relational model?

By supporting complex data types, inheritance, and encapsulation within tables and SQL.

What is stored as objects with attributes and methods in an Object-Oriented Database (OODBMS)?

The data itself—each record is an object that encapsulates data and behavior.

Give two examples of object-oriented database products.

Versant and Objectivity/DB (Oracle 12c also supports object features).

Why were XML hybrid databases introduced in the 1990s?

To store, query, and index XML data while leveraging relational database strengths.

Which two XML-specific query languages are commonly supported by XML hybrid databases?

XQuery and XPath.

What does the acronym NoSQL stand for and what does it imply?

"Not Only SQL"; it denotes non-relational databases designed for flexible, scalable handling of unstructured or semi-structured data.

Name four primary data models used by NoSQL databases.

Key-value, document, columnar, and graph models.

Identify four popular NoSQL systems mentioned in the lesson.

Amazon SimpleDB, Google Bigtable, Apache Cassandra, and MongoDB.

Which features allow NoSQL databases to achieve high scalability and availability?

Automated sharding, replication, and fault tolerance that enable horizontal distribution across many servers.

What trade-off do NoSQL databases often make compared with traditional relational databases?

They may sacrifice strong consistency guarantees and complex SQL-style querying for greater scalability and performance.