Database Concepts

What is NoSQL?

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NoSQL is a term that refers loosely to a particular type of database model, or database management system (DBMS).

NoSQL is a very broad term that doesn’t refer to one particular database model. Rather, it refers to a whole variety of different models that don’t fit into the relational model.

Although NoSQL databases have been around since the 1960s, it wasn’t until the early 2000s that the NoSQL approach started to pick up steam, and a whole new generation of NoSQL systems began to hit the market.

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What does ACID mean in Database Systems?

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In database systems, ACID (Atomicity, Consistency, Isolation, Durability) refers to a standard set of properties that guarantee database transactions are processed reliably.

ACID is especially concerned with how a database recovers from any failure that might occur while processing a transaction.

An ACID-compliant DBMS ensures that the data in the database remains accurate and consistent despite any such failures.

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What’s the Difference between a Graph Database and a Relational Database?

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Graph databases have been gaining popularity over recent years as a viable alternative to the relational model. Graph databases are particularly well suited to storing connected data – data with lots of interconnected relationships, especially those that run many levels deep.

This article looks at the main differences between graph databases and relational databases.

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What is a Graph Database?

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A graph database is a database that uses a graphical model to represent and store the data.

The graph database model is an alternative to the relational model.

In a relational database, data is stored in tables using a rigid structure with a predefined schema.

In a graph database, there is no predefined schema as such. Rather, any schema is simply a reflection of the data that has been entered. As more varied data is entered, the schema grows accordingly.

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Database Tutorial

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This database tutorial is for beginners. It explains basic concepts and assumes no prior knowledge of databases.

You don’t need to follow along – there aren’t any exercises. But there are plenty of screenshots and a few diagrams. The purpose of the tutorial is to introduce you to the basic concepts of databases.

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What is an ORDBMS?

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ORDBMS stands for Object-Relational Database Management System.

An ORDBMS is a database management system that is a hybrid between the object-oriented model (OODBMS) and the relational model (RDBMS).

Each of those two models has their strengths and weaknesses. By combining the two models, a DBMS can take advantage of various strengths from each model.

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What is an OODBMS?

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OODBMS stands for Object-Oriented Database Management System.

An object-oriented database management system (also known simply as an object database) is a DBMS where data is represented in the form of objects, as used in object-oriented programming.

In contrast to relational database management systems (RDBMSs), where data is stored in tables with rows and columns, an object-oriented database stores complex data and relationships between data directly, without mapping to relational rows and columns.

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