Regarding choosing a relational database management system (RDBMS), two popular options are PostgreSQL and MySQL. Both have been around for decades and have proven highly reliable, secure, and scalable. However, they have different strengths and weaknesses that make one more suitable for specific use cases. This article will compare PostgreSQL and MySQL to help you make an informed decision in 2023.
History and Development
PostgreSQL was first released in 1996 and has become a widely used open-source RDBMS. It is known for its strong adherence to SQL standards, robust feature set, and focus on data integrity and security.
MySQL, on the other hand, was first released in 1995 and has been widely used for web-based applications due to its high performance and ease of use. Over time, Oracle acquired the open-source database management system MySQL and turned it into a commercial product.
PostgreSQL and MySQL both offer a wide range of features as relational database management systems, but there are some key differences between the two:
- Data Types: PostgreSQL supports a broader range of advanced data types, including arrays, hstore (a key-value store), and JSONB (binary JSON). On the other hand, MySQL has a more limited set of data types and is geared toward more straightforward web applications. MySQL's JSON binary storage format can be considered comparable to PostgreSQL's JSONB. Indeed, MySQL's JSON storage is well-suited for simpler JSON structures and straightforward web applications.
- Geospatial Support: PostgreSQL strongly supports geospatial data, including a rich set of data types, functions, and operators for handling geographic data. MySQL, while it has some geospatial support, could be more robust in this area.
- Indexing: In MySQL, the default index type is B-tree, which is well-suited for most use cases. PostgreSQL has a more refined indexing system than MySQL, including support for B-tree, GiST (Generalized Search Tree), and GIN (Generalized Inverted Index) indexes. These provide more options for optimizing query performance and data retrieval.
- Replication: PostgreSQL and MySQL perform master-slave database replication, but the methods and options for replication differ. PostgreSQL supports multi-master replication using third-party extensions. MySQL has recently introduced a new replication model called Group Replication, but it is still a relatively new feature with some limitations.
- Transactions: PostgreSQL and MySQL InnoDB utilize MVCC (Multi-Version Concurrency Control) to handle concurrent data access. However, PostgreSQL offers evolved transaction management features such as transaction isolation levels, atomic transactions, and savepoints. In contrast, MySQL's transaction management options are more limited. PostgreSQL may be better for applications requiring high concurrency or complex transaction logic.
- Stored Procedures: PostgreSQL and MySQL support stored procedures, but the language and functionality of stored procedures differ. PostgreSQL supports stored procedures written in various languages, including PL/pgSQL, PL/Tcl, PL/Perl, and more. MySQL, alternatively, primarily supports stored procedures written in SQL.
- Extensions: PostgreSQL has a robust extension framework that allows developers to add custom functionality and extend the core features of the database. While it has some support for extensions, MySQL has a different level of extensibility than PostgreSQL.
Change Data capture.
In terms of change data capture (CDC), both MySQL binary logs and PostgreSQL write-ahead logs (WALs) can capture changes made to the database. However, the specific features and usage of the CDC may vary.
DBConvert Streams is a software that can read MySQL and PostgreSQL transaction logs and transform the records to another dialect, making it suitable for heterogeneous database replication in real time.
MySQL is known for its high performance and ability to process large
amounts of data. It has been optimized for read-heavy workloads and has a fast indexing system that helps improve query performance. However, concurrency issues such as lock contention can occur when combined with write operations, leading to performance degradation. This is due to the implementation of locks at the table level, preventing all actions while the write operation is in progress.
The InnoDB storage engine is used to solve the table-level locking issue. It is one of the most popular and widely used storage engines in the MySQL ecosystem. InnoDB supports row-level locking, improving concurrency for mixed workloads.
Additionally, the recent development of the high-performance storage engine, MyRocks, has further improved MySQL's ability to handle write-intensive workloads.
PostgreSQL is designed to be more versatile, handling both read-heavy and write-heavy workloads, but with slightly lower performance than MySQL, which is optimized for read-heavy workloads. However, PostgreSQL has improved its performance in recent versions, especially regarding complex queries and data processing.
Additionally, PostgreSQL has a more advanced indexing system compared to MySQL, which can improve performance for complex queries. PostgreSQL also supports advanced data types, like arrays and JSONB, which can result in more efficient data storage and retrieval.
Ultimately, the performance of both PostgreSQL and MySQL will depend on various factors, such as hardware, data size, and query complexity.
When choosing between the two, consider your application's specific requirements and conduct performance testing with your data and workloads to determine the best fit.
Both MySQL and PostgreSQL can scale, but they have different strengths and weaknesses when it comes to scalability.
MySQL is often preferred for its horizontal scalability, which means it can be scaled out by adding more nodes to the database cluster. It is ideal for web applications that need to handle a large number of concurrent connections.
On the other hand, PostgreSQL is known for its vertical scalability, which means it can handle large amounts of data and processing power by adding more resources like memory and CPU to a single node. It also supports horizontal scaling through technologies such as sharding, which allows large datasets to be split across multiple nodes. PostgreSQL is preferred for applications requiring complex queries and transactions and for data warehouse and business intelligence workloads.
In terms of scalability, consider the specific requirements of your application. If you need to handle a large number of concurrent connections and need horizontal scalability, MySQL may be a better choice. However, PostgreSQL may be better if you require complex transactions and queries.
In 2023, it is still true that PostgreSQL is fully open-source and community-driven, whereas MySQL has a more complex history concerning licensing. MySQL was initially developed as a commercial product by MySQL AB, with free and paid versions available. The acquisition of MySQL AB by Oracle in 2010 raised some concerns among developers about the future of its open-source status. However, several open-source forks of the original MySQL, including MariaDB and Percona, have helped mitigate these concerns.
When to Use MySQL?
While PostgreSQL has many cutting-edge features and is often considered a more advanced and complex database management system than MySQL, it does have its drawbacks.
Some of the common weaknesses of PostgreSQL include the following:
- Despite its advanced features and capabilities, PostgreSQL has yet to reach the level of popularity and widespread use of MySQL. This has resulted in a smaller number of third-party tools and a lesser number of experienced developers or database administrators in the PostgreSQL ecosystem.
- Due to its advanced features, PostgreSQL can be more complex to set up and manage than MySQL, making it more suitable for experienced database administrators and developers.
- PostgreSQL can be slower in certain use cases than MySQL due to its more complex architecture and features.
- PostgreSQL can require more resources than MySQL, particularly in terms of memory and CPU usage.
- While PostgreSQL is open-source, the cost of implementation and maintenance can still be high due to its advanced features and increased resource requirements.
- PostgreSQL forks a new process for each new client connection, which can allocate a significant amount of memory, typically around 10 MB per connection. However, this architecture is designed to provide improved security and isolation between different clients and is generally considered a trade-off for better performance, reliability, and scalability.
- PostgreSQL is designed to prioritize extensibility, standards compliance, scalability, and data integrity. Sometimes, these features can decrease performance compared to MySQL, especially in simple read-heavy workloads. However, it's important to note that the exact performance difference depends on various factors, such as the data's size, the queries' complexity, and the hardware being used.
Which migration is more common: MySQL to PostgreSQL or PostgreSQL to MySQL?
The migration frequency between MySQL and PostgreSQL varies and depends on individual organizations' needs and requirements. Some organizations may migrate from MySQL to PostgreSQL to take advantage of its advanced features, better SQL compliance, and open-source compatibility. PostgreSQL is also more prevalent in specific industries, such as financial services, government, and data warehousing, where performance, scalability, and security are essential considerations.
On the other hand, other companies may migrate from PostgreSQL to MySQL for its simplicity, broad community of support, and lower cost of implementation.
The migration trend is towards moving from MySQL to PostgreSQL based on various indicators. These indicators suggest that more people are shifting from MySQL to PostgreSQL compared to the reverse.
- Availability of migration tools: Many open-source and commercial migration tools are available to assist in migrating data from MySQL to PostgreSQL. At the same time, there are fewer tools to migrate data from PostgreSQL to MySQL.
- Online resources: There is greater availability of online tutorials and resources on migrating from MySQL to PostgreSQL compared to the other way around.
- Community growth: The PostgreSQL community has been growing faster than the MySQL community, indicating a growing interest in using PostgreSQL over MySQL.
- Open source contributions: The number of open source contributions to PostgreSQL is increasing, indicating that more people are investing time and resources into the technology and finding it useful for their needs.
- Enterprise adoption: Some of the world's largest and most data-intensive organizations, such as Cisco, Fujitsu, and the U.S. Federal Aviation Administration (FAA), have publicly stated that they have moved from MySQL to PostgreSQL.
- User surveys: Industry analysts and database experts have conducted surveys that suggest that more people are considering or planning to switch from MySQL to PostgreSQL.
These facts only indicate that more migrations happen from MySQL to PostgreSQL than the other way around, and it may only be true in some cases.
PostgreSQL and MySQL are robust relational database management systems with unique features and limitations. The decision to use one over the other should be based on the specific requirements of a project, such as the nature and amount of data, the intricacy of queries, and performance and scalability needs. As both PostgreSQL and MySQL are set to undergo further advancements in 2023, it is crucial to stay updated on their recent developments.
In addition, it's worth mentioning that tools like DBConvert Studio can help with migrating data between MySQL and PostgreSQL in either direction. These tools can simplify the process of transferring data from one database to another, which can be especially useful if you consider switching from one system to another.