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Maximizing Performance: Alternatives to PostgreSQL’s In-Memory Database Support

Introduction to In-Memory Database

With technology advancing at an unprecedented rate, the demand for real-time systems and gaming applications has surged. These applications require high-speed processing and constant data availability.

The traditional relational database management systems (RDBMS) may not be able to meet these requirements, leading to the rise of in-memory databases. An in-memory database, as the name indicates, stores data in the Random Access Memory (RAM), providing faster access and quicker processing.

In this article, we will discuss the advantages and disadvantages of using an in-memory database, the SQL platforms offering support for it and alternatives to PostgreSQL support using an in-memory database.

Advantages and Disadvantages of In-Memory Database

The primary benefit of using an in-memory database is quick access to data. Since the data is stored in RAM, the response time is significantly faster compared to traditional disk-based databases.

This increased speed is essential for real-time systems and gaming applications that require real-time data availability. Another advantage is the faster processing of transactions.

The in-memory database architecture eliminates the need for data movement between disk and memory, reducing the overhead for disk memory swap operations. Consequently, it provides faster processing of transactions.

However, in-memory databases have some drawbacks. The data in the RAM is volatile, which means that it is lost in case of a power outage or system failure.

Hence, in-memory databases must be backed up regularly to ensure data integrity. Moreover, the cost of RAM is higher compared to disk storage.

Hence, an in-memory database may require more resources and, therefore, may not be cost-effective for all applications.

Other SQL Platforms with In-Memory Database Support

SQL Server is a popular SQL platform that offers support for in-memory databases through In-Memory OLTP. This feature allows high-speed transaction processing by storing the transactional data in memory.

This architecture provides significant performance improvements through reduction of read/write operations, log scanning and recovery overheads, and lock contention. However, it requires a comprehensive design analysis of tables, stored procedures, and indexes to leverage this feature.

Alternative: Using Tablespaces

PostgreSQL, a popular free and open-source RDBMS, does not support in-memory databases. However, PostgreSQL offers tablespaces, which can be used as an alternative to in-memory databases for frequently accessed tables.

Tablespaces are disk-based storage areas that can be created on separate file systems. By mapping frequently accessed tables to tablespaces residing on high-performance disk systems, we can achieve better performance and load balancing.

However, tablespaces lack the benefit of in-memory databases regarding response time as they still require disk read/write operations.

Drawbacks of Using Tablespaces in Memory

Unlike in-memory databases, tablespaces are volatile if not backed up regularly. Hence, in case the disk system fails or loses data, the data stored in memory may be lost.

Moreover, the disks on which tablespaces are created may become slow or unavailable due to system issues, leading to slower processing times. Alternative: Creating Throwaway PostgreSQL Instance

An alternative to tablespaces is creating a disposable PostgreSQL instance for unit testing.

This instance can use different memory sizes and configurations, allowing developers to simulate different production environments. For smaller systems, developers can use the initdb command to start a new PostgreSQL instance with a specific memory size.

For larger systems, the pg_ctl command can be used to start and stop PostgreSQL instances. This approach allows for quick and easy experimentation and ensures a clean slate for each test.


In-memory databases and tablespaces have their advantages and disadvantages. While in-memory databases provide faster processing and response times, they come with a higher cost and increased risk of data loss.

Tablespaces, on the other hand, provide better performance than disk-based RDBMS, but lack the benefits of in-memory databases and have their own drawbacks. By using a throwaway PostgreSQL instance, developers can simulate production environments, allowing for efficient testing and experimentation.

Choosing the best alternative depends on the specific application requirements and budget constraints. PostgreSQL is a powerful open-source database management system that has been around for over 30 years.

While PostgreSQL has a broad range of features, it has some limitations when it comes to in-memory database support. In this article, we will look at PostgreSQL’s limitations when it comes to in-memory databases and explore some of the alternatives that can be used.

PostgreSQL Limitations with In-Memory Database

PostgreSQL relies heavily on the C language for its development. While this provides many benefits, it also means that in-memory database support has not been a priority in its development.

PostgreSQL does not provide native support for in-memory databases, and there is no support for storing tables in memory. Potentially, we can use Linux ramfs to create a file system in memory, but this approach can lead to data loss if the system crashes.

Alternative: Using Tablespaces

Tablespaces provide an alternative to storing frequently accessed tables in memory. Instead, tablespaces are created on separate file systems, which can improve overall system performance.

When tablespaces are used, we can map tables to specific tablespaces where they are stored separately from the rest of the database or transaction logs. The benefit of using tablespaces is that they can be stored on high-performance disks, which reduces access times when they are accessed.

Despite their benefits, tablespaces still require disk read/write operations, which makes them slower than in-memory databases. Moreover, tablespaces are volatile and can lead to data loss if the disk system fails or loses data.

Alternative: Creating Throwaway PostgreSQL Instance

Another alternative is to create a throwaway PostgreSQL instance for unit testing. Developers can use this instance to simulate different production environments with different memory sizes and configurations.

The instance is easy to create using the initdb or pg_ctl command, allowing developers to experiment with different scenarios. This approach allows for quicker and more efficient testing, with the assurance of a clean slate for each test.

However, creating a throwaway PostgreSQL instance for each test can be resource-intensive and may require a significant amount of memory. Alternative: Memcached

We can also use Memcached to store frequently accessed data in memory.

Memcached is an open-source, high-performance, distributed caching system that provides an in-memory key-value store for caching frequently accessed data. Memcached can be used as a standalone caching layer or integrated with PostgreSQL to provide in-memory storage for frequently accessed tables.

When used standalone, Memcached provides fast access to frequently accessed data. When used in conjunction with PostgreSQL, Memcached can be used to cache data from frequently accessed tables, reducing disk I/O and providing faster response times.

Disadvantages of Memcached

One of the biggest disadvantages of using Memcached is data redundancy. Since Memcached is a memory-based caching system, it does not provide data persistence.

This means that data is lost when Memcached is restarted, which can cause data inconsistency. Another disadvantage is that Memcached is not transactional.

This means that when Memcached is used to cache data from frequently accessed tables, updates to the data in PostgreSQL do not update the data in Memcached. This can result in data inconsistency and the need for manual synchronization.


In conclusion, PostgreSQL limitations regarding in-memory database support can be addressed by using alternatives like tablespaces, creating throwaway PostgreSQL instances, or integrating with Memcached. While tablespaces provide faster access times for frequently accessed tables, they still require disk read/write operations and can lead to data loss.

Creating throwaway PostgreSQL instances allows developers to simulate different production environments but can be resource-intensive. Memcached provides an in-memory key-value store for caching frequently accessed data and can be used either as a standalone caching layer or integrated with PostgreSQL.

However, data redundancy and inconsistency can be issues when Memcached is used. When choosing the best alternative, it is essential to consider the application requirements, budget constraints, and the trade-offs between performance and reliability.

By considering all these factors, developers can choose the best alternative to meet their needs. In conclusion, PostgreSQL lacks native support for in-memory databases due to its reliance on the C language.

However, alternatives like tablespaces, throwaway PostgreSQL instances, and Memcached can address this limitation and provide benefits like faster access, improved performance, easy testing, and caching frequently accessed data. Each alternative has its drawbacks, such as data redundancy and loss or inconsistent data, that should be considered before choosing one.

Future research and development in this area can further improve database management systems and benefit real-time systems and gaming applications, among others.

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