Chief Product Officer, Ispirer Systems
Over the past 5 years, MySQL and PostgreSQL have gained popularity, due to being open-source and free-to-use. However, choosing the right database involves more than just cost considerations. This article aims to help you make an informed decision by providing a detailed comparison between PostgreSQL and MySQL.
If you're struggling to choose the right database for your project requirements, this article is a must-read. We'll simplify the complexities and answer all your questions to make the decision-making process easier for you.
What is PostgreSQL?
PostgreSQL is a powerful open-source database system. It supports various SQL functions such as foreign keys, subqueries, triggers, and user-defined types and functions. PostgreSQL is a highly stable database backed by more than 20 years of development by the open-source community. This database further augments the capabilities of SQL by offering features that scale and reserve data workloads.
PostgreSQL is a reliable and versatile database with a rich set of capabilities. Here are some of its best features that make it a preferable choice:
- Advanced querying capabilities. PostgreSQL has strong querying features, including support for recursive queries, CTEs, subqueries, complex SQL queries, and window functions. Additionally, it supports user-defined functions (UDFs), triggers, and stored procedures in a number of programming languages.
- Transaction support. PostgreSQL adheres to the ACID (Atomicity, Consistency, Isolation, Durability) principles, guaranteeing trustworthy and reliable transaction support. It supports layered transactions, savepoints, and various transaction isolation levels and offers explicit transaction control.
- Expansive Data Types and Extensibility. PostgreSQL offers a large variety of built-in data types and extensibility. These features allow programmers to define their own custom data types. PostgreSQL can handle complex data effectively with support for arrays, JSON, and geometric types.
Diverse cases require using PostgreSQL as the right database. Here are the most common ones:
- Web applications. PostgreSQL works fine with all modern web frameworks including but not limited to: Django (Python), node.js (JavaScript), Hibernate (Java), Ruby on rails, PHP, and a lot more. Due to PostgreSQL’s replication capabilities, websites can easily be scaled out to as many database servers as you need.
- Geographic information systems (GIS). Many people prefer PostgreSQL for mapping and related services because it offers advanced support for geospatial data.
- Data warehousing. PostgreSQL enables businesses to store and analyze large amounts of data for reporting and business intelligence.
- Data analytics. With the right extensions and configurations, PostgreSQL can support analytical processing and reporting. (More on extensions and configurations later.)
- Social media platforms. Companies use PostgreSQL to manage user profiles, posts, connections, and interactions.
What is MySQL?
Oracle developed MySQL, a relational database management system (RDBMS) based on structured query language (SQL). In 2023 MySQL ranks among the top three most popular databases in the world.
My Database, named after the founder's daughter, is a system that organizes data into tables and links related data types together. The strength of the system lies in its ability to establish relationships between different data tables. This relational structure connects data types, enabling a coherent and structured representation of information.
SQL is used to organize and manipulate data in relational databases. Tables' relationship is the foundation for modern database systems and is still present in most of them.
MySQL has its own clients for users to use with other programs when they need relational database capabilities. MySQL is reliable and used in popular software stacks like LAMP. It is also used in CMS options such as Drupal, Joomla, phpBB, and WordPress.
MySQL is a popular choice for game development companies. The biggest game development studios such as Activision Blizzard use MySQL as the database back end for various video games. But in most cases, users prefer MySQL for web projects. Here are the most popular use cases:
- Web development. MySQL can support any web application use case. MySQL is used by big websites like eBay and Dropbox to store user information and login details. The fact that MySQL is a go-to choice for Wells Fargo and JPMorgan Chase companies proves that MySQL is the best choice for web development projects.
- Game development. MySQL is commonly used by major game studios like Activision Blizzard as the database for video games.
- Managing content for websites and blogs. MySQL excels in storing and retrieving content for blogs and websites that need to serve content quickly to keep readers engaged. This could include article texts, comments, article metadata, and lists of email subscribers.
- E-commerce. E-commerce sites can use MySQL to store product price data and which items are on sale. They can use it for affiliate partner performance data to track how much affiliates are selling.
Performance
PostgreSQL is designed to handle both read-heavy and write-heavy workloads. However, it may have slightly lower performance than MySQL. MySQL is optimized for high read loads. In newer versions, PostgreSQL has improved its performance, especially for complex queries and data processing.
Moreover, PostgreSQL boasts a more sophisticated indexing system than MySQL, which can boost performance for intricate queries. PostgreSQL also accommodates advanced data types like arrays and JSONB, potentially leading to more effective data storage and retrieval.
MySQL is renowned for its superior performance and capacity to handle vast volumes of data. It's designed for tasks that require lots of data reading and it has a fast indexing system to improve query speed. However, when performing write operations, concurrency problems such as locks may occur, which leads to poor performance. This happens because table-level locks stop any actions while a write operation is being carried out.
The InnoDB storage engine is used to solve the problem of locks at the table level. InnoDB is among the most commonly utilized data storage systems in the MySQL environment. It offers support for row-level locking, which enhances concurrency for diverse workloads.
When choosing between these two systems, you should consider the specific requirements of your application and perform performance tests with your data and workloads to determine the best option. But it is no less important to take into account hardware, data volume and query complexity.
SQL Syntax Overview
In terms of syntax, Postgresql and MySQL share many similarities. However, MySQL lacks support for certain subqueries such as "LIMIT" or "ALL", and it also doesn't accommodate standard SQL clauses like "INTERSECT" or "OUTER JOIN". SQL syntax in MySQL compliance isn't as comprehensive as in PostgreSQL, which does include all the aforementioned sub-queries. If your business operations frequently require these subqueries, then PostgreSQL would be a more suitable option.
To seamlessly transition from any database to either PostgreSQL or MySQL, it is crucial to take into account SQL. If your source database involves intricate SQL structures, migrating to PostgreSQL is advisable. This choice streamlines the migration process, particularly for elements like user-defined data types and sequences, along with advanced features like XML processing present in the source databases.
Nevertheless, if MySQL better aligns with your requirements for reasons beyond SQL complexities, it is worth choosing MySQL. Overcoming migration challenges is achievable, especially when utilizing Ispirer Toolkit. In essence, when considering MySQL migration, prioritize the solution that aligns best with your specific tasks, and rest assured that our tool facilitates a smooth transition.
Architecture
PostgreSQL and MySQL have some differences in their architecture. PostgreSQL is an object-relational database, while MySQL is simpler and purely relational.
In terms of storage, PostgreSQL uses a single, ACID-compliant engine. On the other hand, MySQL supports 16 different engines for various use cases, and its default engine, InnoDB, organizes tables efficiently.
When it comes to handling connections, PostgreSQL allocates a new system process and memory for each client connection, making it memory-intensive for systems with many connections. In contrast, MySQL uses a single process and a thread for all connections, which works well for most applications that aren't massive.
In terms of common database features like views, triggers, and stored procedures, PostgreSQL has more robust views and supports materialized views for better performance in complex queries.
Both databases support triggers for SQL operations, but PostgreSQL has some extra features like an INSTEAD OF trigger and the ability to execute complex SQL statements in triggers using functions. Both also handle standard SQL stored procedures, but PostgreSQL goes a step further by allowing procedures in languages other than SQL.
JSON
PostgreSQL started supporting JSON data types from version 9.2. The JSON data support in PostgreSQL is much more advanced compared to MySQL. There are several JSON-specific operators and functions, making data searches in JSON documents very efficient.
MySQL just started supporting JSON data types recently (from Version 5.7), years later than PostgreSQL. The JSON data columns can be queried using SQL queries, and JSON attributes can be indexed as well. However, the support for JSON-specific functions is limited compared to PostgreSQL. Another limitation of MySQL is that there is no support for Full-Text Indexing on JSON columns. Since MySQL is not fully JSON compliant, it may not be a great choice for storing and processing JSON data.
Indexes
MySQL adopts the B-tree as its default index type, a choice well-aligned with the requirements of a broad range of use cases. It also offers the following index options:
- Indexes stored on R-trees, such as indexes found on spatial data types
- Indexes stored on B-trees, such as PRIMARY KEY, INDEX, FULLTEXT, and UNIQUE
- Inverted lists and hash indexes when utilizing FULLTEXT indexes
PostgreSQL has a complex indexing system that includes B-tree, GiST, and GIN indexes. PostgreSQL has many tools to improve query performance and make data retrieval easier.
Database administrators can customize their indexing strategies to match the unique characteristics and needs of their data. This customization leads to a highly optimized and effective system.
Partitioning
Both MySQL and PostgreSQL offer table partitioning as a means to enhance query performance for large tables. In the case of MySQL, it supports declarative table partitioning with partition types such as RANGE, LIST, HASH, KEY, and COLUMNS (RANGE and LIST). Additionally, SUBPARTITIONING is also supported. Despite these features, there are limitations that might restrict flexibility for DBAs.
PostgreSQL offers two approaches to table partitioning: partitioning by inheritance and declarative partitioning. Declarative partitioning, introduced in Version 10, bears similarities to MySQL, while partitioning by inheritance relies on triggers or rules. The advantages of employing a precise partitioning strategy are notably pronounced when dealing with tables containing substantial data volumes. Supported partitioning types include RANGE, LIST, and HASH.
Security Features
PostgreSQL and MySQL both offer user and group management, along with SQL rights for different roles. MySQL provides user authentication through native window services, PAM, and LDAP, whereas PostgreSQL uses IP-based client authentication and filtering via Kerberos and PAM. Therefore, both databases are on par when it comes to security.
Extensibility
PostgreSQL stands out as an exceptionally versatile tool due to its support for a range of advanced data types that are not present in MySQL. These encompass network address types, native UUID, geometric/GIS, JSON (indexable), and timezone-aware timestamps. If these features weren't convincing enough, PostgreSQL further distinguishes itself with customizable operators, data types, and index types.
Therefore, if your application struggles with unstructured data or relies on any of these unique data types, PostgreSQL emerges as the more suitable choice. However, for scenarios involving only basic numeric and character data types, both databases should function adequately.
Replication
Replication is a method enabling developers to duplicate data from a database to its replicas, ensuring uniform information availability for all users. This process brings several advantages, including fault tolerance, scalability, automated backups, and the ability to execute lengthy queries without impacting the primary cluster.
Both MySQL and PostgreSQL support replication. PostgreSQL provides synchronous replication, maintaining two databases concurrently, where the primary database synchronizes with its duplicate. With PostgreSQL, synchronous and cascading replication is also possible.
In contrast, MySQL's replication is one-way and asynchronous. Here, a single database server serves as the primary, while others function as replicas.
Scalability
Both MySQL and PostgreSQL can scale, but they have their own strengths and weaknesses in this matter.
MySQL is frequently chosen due to its horizontal scalability, implying that its capacity can be increased by incorporating new nodes into the database cluster. It's perfect for web applications requiring to manage a high volume of concurrent connections.
PostgreSQL is good at handling lots of data and can increase its computing power by adding more memory and processors. It can also scale horizontally by using sharding to divide large amounts of data into multiple nodes. PostgreSQL is best for complex queries, transactions, data storage, and business intelligence tasks.
In terms of scalability, it is advisable to think about your application’s unique needs. If your application demands managing numerous simultaneous connections and necessitates horizontal scalability, MySQL might be the optimal selection. However, PostgreSQL is more suitable when complex transactions and queries are needed.
Conclusion
Most companies now prefer PostgreSQL over MySQL for migration, as indicated by migration trends. This is often explained by the fact that PostgreSQL is actively implemented in large companies such as Cisco, Fujitsu, as they have publicly stated, the growing interest in PostgreSQL, online resources and a large number of PostgreSQL migration tools.
Although there are tools that migrate databases to PostgreSQL and MySQL equally well. For example, Ispirer Toolkit. Due to the intelligent core, the tool makes it easy to transfer any database automatically. If you are looking for ways to migrate MySQL or PostgreSQL, you should definitely try Ispirer Toolkit that will save a bunch of time and effort.