MySQL vs PostgreSQL: A Comprehensive Comparison of the Most Popular Databases

When it comes to choosing a database management system (DBMS), PostgreSQL and MySQL are two of the most popular options available. Both are open-source relational databases that organize data into tables and can be linked based on common data. However, there are several differences between the two that make them unique.

Database Type

MySQL is a relational database, which means that it organizes data into tables with rows and columns. Each row represents an entity, and each column represents an attribute of that entity.

For example, a table of students might have columns for name, age, grade, and so on. To access data from a relational database, you need to use a query language like SQL, which specifies the conditions and operations to retrieve the data you want.

PostgreSQL is an object-relational database, which means that it supports both relational and non-relational data types. Non-relational data types are those that do not fit into the table structure, such as arrays, documents, images, or custom objects.

PostgreSQL allows you to store these types of data as columns in a table, and also provides functions and operators to manipulate them. For example, you can store an array of phone numbers for a student, and use the array functions to add, remove, or search for a specific number.

You can also store a document in JSON format, and use the JSON operators to access or modify its properties.

🐘 PostgreSQL: It’s an object-relational database.
Supports both relational and non-relational data types. Non-relational data types are those that do not fit into the table structure, such as arrays, documents, images, or custom objects.

🐬 MySQL: It’s a relational database.

Best pick: Depends on whether you need object-oriented features or not.

Programming Language & Extensibility

MySQL is written in C/C++, which are two of the most widely used programming languages in the world.

C/C++ are low-level languages that offer high performance and efficiency, but also require more coding and debugging effort.

However, MySQL does not allow users to write their own extensions or customizations in C/C++.
Instead, MySQL provides a limited set of APIs and interfaces for users to create plugins, stored procedures, user-defined functions, and user-defined types.

PostgreSQL is written in C, which is the predecessor of C++ and the most influential programming language in history.

C is also a low-level language that offers high performance and efficiency, but also requires more coding and debugging effort.

PostgreSQL also allows users to write their own extensions or customizations in C.
It provides a rich set of APIs and interfaces for users to create plugins, stored procedures, user-defined functions, user-defined types, and even new languages.

🐘 PostgreSQL: Written in C. It supports a wider range of programming languages.
🐬 MySQL: Written in C/C++. It has limited support for server-side programming in a non-extensible language.

Best pick: PostgreSQL, due to its extensibility and support for more programming languages.

Support for CASCADE

🐘 PostgreSQL: Supports CASCADE Checks and CASCADE Foreign key constraints.
🐬 MySQL:

• Supports CASCADE foreign key constraints when using InnoDB.
• Other storage engines in MySQL, such as MyISAM, do not support foreign key constraints.
• No support for CASCADE checks.

Best pick: PostgreSQL, as it supports full CASCADE operations.

Performance

MySQL outperforms PostgreSQL in read-heavy scenarios, thanks to its versatile storage engine model.
InnoDB, MySQL's predominant storage engine, employs clustered indexing, associating the primary key with the actual disk location for swift data retrieval.
Additionally, InnoDB utilizes adaptive hashing to enhance memory-based data caching, bolstering read performance.

In contrast, PostgreSQL follows a single storage model, relying on heap files and write-ahead logs (WAL). The heap file stores table data, while WAL logs all database modifications.
PostgreSQL adopts multi-version concurrency control (MVCC) to enable concurrent access without locking, presenting transaction snapshots. However, this strategy generates multiple row versions, necessitating periodic cleanup through vacuuming.
PostgreSQL employs sequential scans for heap file data retrieval, potentially lagging behind index scans.

Consequently, MySQL excels in read-heavy tasks, especially with uncomplicated queries that utilize primary keys. Conversely, PostgreSQL shines in write-heavy scenarios, leveraging its extensive feature set and capabilities for complex data operations.

🐘 PostgreSQL: Handles large data sets, complicated queries, and read/write operations more quickly.

• CTEs (Comment table expressions)
• Advanced query optimizer and planner.
• MVCC model, which allows concurrent writes without locking or blocking, and its WAL, which ensures data durability and consistency.

🐬 MySQL: Faster for read-heavy operations.

• When using InnoDB, it uses a clustered index to store data, which means that the primary key of each table is also the physical location of the row on disk.
• InnoDB also uses adaptive hashing to cache frequently accessed data in memory, which improves the read performance.

Best pick: Depends on the specific use case (read-heavy or write-heavy).

Security

PostgreSQL offers robust security compared to MySQL with its row-level security (RLS) and encryption features:

RLS lets you set rules to control user access to specific table rows, eliminating the need for multiple tables/views. Introduced in PostgreSQL 9.5 and improved over time.

Encryption safeguards data in different ways:

1. Transport-level encryption secures client-server communication using SSL/TLS protocols, preventing network eavesdropping and attacks. PostgreSQL has supported SSL since version 7.134.
2. Data-at-rest encryption encrypts stored data, protecting against physical server access or backup file theft.
3. Data-in-use encryption secures data in memory or during transit within the database.

MySQL lacks native RLS but can use views or triggers for row-level access control, albeit less efficiently and more complexly. MySQL supports SSL but lacks certificate-based authentication and temporary file encryption.

While MySQL supports data-at-rest encryption with InnoDB, it does not offer data-in-use encryption or transparent data encryption (TDE).

🐘 PostgreSQL: Has in-built SSL support and the ability to encrypt client/server communications. It also offers a fine-grained approach to user privileges. Row Level access permisions
🐬 MySQL: Bases its security features on Access Control Lists (ACLs).

Best Pick: PostgreSQL, due to its advanced security features.

Community Support

🐘 PostgreSQL: Has a large community of volunteers who offer free advice. The community has been growing faster than the MySQL community.

🐬 MySQL: Also has a robust community support.

Winner: Both have strong community support, but PostgreSQL’s community is growing faster.

Indexing

Indexing enhances database data retrieval efficiency. An index is a data structure storing specific table data, like column values or combinations. It allows swift data location based on conditions, avoiding full table scans and aiding sorting, grouping, and joining.

PostgreSQL outshines MySQL in indexing capabilities, supporting a broad range of types, features, and customizations for scalability and performance:

1. PostgreSQL offers diverse index types like GiST, SP-GiST, GIN, BRIN, and partial indexes, tailored for various data and queries, e.g., geospatial, full-text, array, range, and conditional queries.
2. Expression indexes in PostgreSQL are based on functions, enhancing query performance for complex calculations or transformations.
3. Index-only scans retrieve data directly from the index, improving queries that select indexed columns or use filter conditions.
4. Concurrent index creation in PostgreSQL allows non-disruptive index building, enhancing database availability and performance.

These advanced capabilities make PostgreSQL more suitable than MySQL for complex queries.

🐘 PostgreSQL: Supports many types of indexes, including GIN and Hash.

🐬 MySQL: Primarily uses Binary Search Tree (B-Tree) for indexing.

Winner: PostgreSQL, due to its support for a variety of index types.

Architecture

🐘 PostgreSQL: Managed with an object-relational database management system (ORDBMS).

• Multi-process, Multi-threaded architecture.
• Extensible architecture.

🐬 MySQL: An open-source relational database system backed by Oracle.

• Single threaded architecture

Winner: Depends on the specific requirements of your project.

How to Choose Between PostgreSQL vs MySQL

When choosing between PostgreSQL and MySQL, it’s important to consider your specific needs and requirements. Here are some factors to consider:

1. Data Type: If you need to store non-relational data types, PostgreSQL is the better choice.
2. Programming Language: If you need a DBMS that is more extensible and customizable, PostgreSQL is the better choice.
3. Performance: If you have read-heavy workloads, MySQL is the better choice. If you have write-heavy workloads, PostgreSQL is the better choice.
4. Security: If you need advanced security features, such as row-level security and encryption, PostgreSQL is the better choice.
5. Community Support: If you need a more active and engaged community, PostgreSQL is the better choice.

Comparing PostgreSQL and MySQL in Different Use Cases

Here is a table that compares PostgreSQL and MySQL in the following use cases:

MySQL’s and PostgreSQL’s Shared Features and Unique Advantages

MySQL and PostgreSQL are two of the most popular database systems in the world. They have many things in common, but they also have some distinctive features that make them suitable for different use cases. In this section, we will look at some of the similarities and differences between these two database systems.

Both MySQL and PostgreSQL have the following characteristics:

1. They have large and helpful communities that provide support and guidance. If you need more advanced support, you can also find professional service providers that offer it.
2. They use SQL (Structured Query Language), the most widely used language for data management systems. SQL allows you to query and join tables in a simple way, and it is easy to learn for non-technical team members.

In recent years, MySQL has added some features that used to be exclusive to PostgreSQL. However, these features are not exactly the same in both systems:

1. Common Table Expression (CTE): CTE is a temporary result set that you can refer to in a SELECT, INSERT, UPDATE, or DELETE statement. PostgreSQL has supported CTE since version 8.4, while MySQL has added it in version 8.0.
2. Geographic Information System (GIS) and Spatial Reference System (SRS): GIS and SRS enable you to store and analyze spatial and geographic data. PostgreSQL has a powerful extension called PostGIS that provides this functionality. MySQL supports GIS and SRS, but it is not as advanced as PostGIS.
3. JSON Compatibility: JSON is a format that allows you to store and transport data. PostgreSQL supports JSON and JSONB, which is a binary version that removes duplicate keys and extra whitespace. MySQL supports JSON, but not JSONB.
4. Multi-Version Concurrency Control (MVCC): MVCC allows multiple users to access the same data without locking or blocking each other. PostgreSQL has implemented MVCC since its inception, while MySQL has adopted it in its InnoDB storage engine.

Conclusion

Both PostgreSQL and MySQL have their strengths and weaknesses. The choice between the two depends on your specific requirements for a project and your experience as a database administrator. However, PostgreSQL is generally considered more flexible, customizable, and secure than MySQL, making it a better choice for large-scale applications.

Frequently Asked Questions (FAQ)

What is the main difference between PostgreSQL and MySQL?
PostgreSQL is an object-relational database management system (ORDBMS) that emphasizes extensibility and SQL compliance. MySQL is a relational database management system (RDBMS) based on SQL (Structured Query Language).

Why choose PostgreSQL over MySQL?
PostgreSQL is known for its support of advanced SQL features, including transactions, foreign keys, and triggers. It is also highly scalable and can handle large amounts of data. and its support for ACID (Atomicity, Consistency, Isolation, Durability) transactions. This means that PostgreSQL ensures that all transactions are completed successfully or not at all. This makes it an ideal choice for applications that require high levels of data integrity.

Why choose MySQL over PostgreSQL?
MySQL is known for its speed and read performance. It is also easier to use and has a larger community than PostgreSQL, making it a better choice for small-scale applications, such as blogs or e-commerce sites.

Which database is more extensible, PostgreSQL or MySQL?
PostgreSQL is more extensible as it supports a variety of programming languages and has a wide range of extensions.

Do both PostgreSQL and MySQL support CASCADE operations?
Yes, both PostgreSQL and MySQL support CASCADE operations. However, PostgreSQL also supports CHECK constraints, which MySQL does not.

Which database is known for its performance optimization?
PostgreSQL is known for its performance optimization, high concurrency, and efficient use of hardware resources.

Which database has more advanced security features?
PostgreSQL has more advanced security features compared to MySQL.

Which database has a larger community?
MySQL, being older and more popular, has a larger community and more third-party tools.

Which database supports a variety of index types?
PostgreSQL supports a variety of index types, including B-tree, hash, and GIN.

Which database has a more advanced architecture?
PostgreSQL’s architecture is highly sophisticated and extensible.

Do the CASCADE foreign key constraints work on all MySQL storage engines?
The CASCADE foreign key constraints in MySQL work specifically with the InnoDB storage engine. Other storage engines in MySQL, such as MyISAM, do not support foreign key constraints.