What are schemas in databases? (With different types)

By Indeed Editorial Team

Published 24 May 2022

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Schemas are the blueprint for a database, helping users to organise and programme their data entries. They're an ideal way for companies to store big data, organising it effectively so that it's easy to locate and analyse. This is important when you consider the role data plays in large organisations today. In this article, we answer the question, 'What are schemas in databases?', then examine the different types and the professions that rely on them the most.

What are schemas in databases?

To answer, 'What are schemas in databases?', you can think of a schema as a database's blueprint. It's the formal programming language that supports the database's management system, dictating how personnel input data, how it's structured and how it's organised into legible information. A schema is something that a lot of computer applications depend on, meaning it's not quick or easy to create. It can take professional developers weeks to make one, as it may require them to adapt their code so that it can fit into the new model.

What's in a database schema?

In database schemas, there are a few common features. First, it has to include all relevant information that pertains to the database in question. This ensures there are no gaps in the database due to missing entries. Second, all inputted entries require the same format. An inconsistent, messy database can look unprofessional. It can also make it much harder and more time-consuming to locate the entries that you require.

Third, all entries and objects require their own unique key. Without it, data can blend together and specific entries can become lost. This also gives a rather unprofessional and incompetent impression. Lastly, each column within a database needs its own name and data type. This is for organisational purposes, as it makes a database easier to navigate and much more presentable.

What are the types of database schemas?

There's no single solution when it comes to database schemas. This means that the type of database used to store information can vary according to what data you are inputting. This means there are various types of database schemas:

Physical database schemas

A physical database schema refers to how a piece of hardware stores data and how its different elements communicate with each other. When looking in greater detail at this model, a diagram can be helpful. It can convey where you have stored which files, including where the relevant indexes are. The diagram can also explain how the database on this piece of hardware is set up so that it's both faster and easier to find a specific data entry. The schema also portrays how the database can help with connectivity or storage issues.

Logical database schemas

A logical database schema uses a series of tables to organise data, portraying how the different attributes of each table link together according to their relationship with one another. It's also known as entity relationship modelling. To run successfully, entity relationship modelling needs a primary key, as this is what identifies a specific record in the table. It also requires a foreign key, which is the primary key in another table that links together both tables, establishing a relationship. You can either create a logical database schema manually or through the use of online tools.

SQL server database

An SQL server is a relational database management system that is specially designed for worldwide relational databases. It helps businesses to both organise and store their complex pieces of data within a wide variety of database types. You can do this using a table, inputting entries inside each individual row and adding specific information pertaining to that entry in the corresponding column. By organising data this way, you make it much easier to update and query. This means less time scrolling through the system looking for one specific piece of information.

PostgreSQL server database schemas

A PostgreSQL database uses a namespace schema, a term given to the unique naming of objects so they're easily identifiable, that complies with the SQL database and its programming language. It's a free, relational, open-source database system that allows users to manage the input of different tables, indexes, functions, data types and operations. Although this type of database allows for the input of different schemas, it can only happen on one level rather than in a hierarchy. PostgreSQL schema inputs data publicly, but doesn't share this between users with the same object name across one cluster.

NoSQL server database

The NoSQL database is a non-relational alternative to an SQL Server database, primarily because it contains a non-linear structure. As a management system, it goes beyond what an SQL database can do and, sometimes, doesn't contain a like-minded programming language. This means that it's the ideal database type for semi-structured documents due to its formatting capabilities and wide column stores, which need a more varied formatting structure. It's also used for key value stores and graphs as the database organises its data into edges and nodes with relationships highlighted.

How are schema databases different from Excel?

It's a common misconception that schema databases and Excel do the same thing. Although they both deal with the input of data into rows and columns, schema databases are much more capable. Aside from their greater power, which means that they're able to handle structure and organise billions more rows than Excel, schema databases can also use other programming languages, such as Java or Python, to streamline user experiences. Schema databases allow for greater interactivity, as an Internet connection alone means that various employees can have simultaneous access to one database for maximum efficiency.

Which professions use schema databases?

The procurement of information is becoming increasingly important for companies in today's technological society. This means that schema databases, in particular, are in use across a variety of different businesses to ensure they stay ahead of the competition. This supports a variety of jobs, including:

Database administrators

If schema databases didn't exist, then the database administration profession wouldn't either. It's their job to ensure that schema databases are working properly for the other professions on this list. Part of a schema database administrator's workday includes using their software programming skills to troubleshoot and fix any apparent errors. For example, pieces of data may have blended together, as some users didn't create a unique key for each entry. In addition to this, schema database administrators create code, optimise it, back up database systems and protect it from any security threats.

Related: How to become a database administrator

Data scientists

The job of a data scientist is to sift through huge amounts of data, filtering out what is unnecessary and converting useful pieces of raw data into legible information. This means that the use of a schema database is paramount, as data scientists then need somewhere to store the information that they want to keep. They can do this on a schema database by making use of the billions of input fields, working collaboratively with other company arms that can also access this database. Businesses can then use this information, for example, in marketing campaigns.

Related: How to become a data scientist in 4 steps

Business analysts

A schema database is important in many analytical business professions. This is because they need consistent access to a wide database so that they can easily pull up information on product performance, maintenance or development, and compare this with the corresponding information for their competitors' products. This allows them to clearly see which areas they want to improve upon to make their product better. A schema database is ideal for this function thanks to its entry space and its ability to effectively organise information. This means the business analyst can spend less time searching for the entries they require.

Related: How to become a business analyst (with roles and salaries)


Databases help journalists to store all of their relevant data and information on a story in one convenient space, making use of the billions of fields that a schema database can handle. Incidentally, when they want to find a statistic to include in an article, they can quickly and efficiently find it within this kind of database. Schema databases are easy for journalists to use as they work on laptops, meaning they can access records on the go as long as they have an Internet connection.

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