Learn how to adjust max_connections in PostgreSQL. Our PostgreSQL Support team is here to help you with your questions and concerns.

Adjusting max_connections in PostgreSQL

The `max_connections` parameter in PostgreSQL determines the maximum number of concurrent connections to the database server.

By default, this value is typically set to 100 connections, but it can be less if the system’s kernel settings do not support it. Before increasing this value, our experts recommend considering the application’s behavior and the system’s resources.

Increasing the `max_connections` parameter allows more clients to connect to the PostgreSQL server simultaneously. However, doing so without considering system resources can lead to CPU and I/O subsystem overloads. This can even degrade performance.

Steps to Adjust max_connections in PostgreSQL

1. First, check the current value of the `max_connections` parameter:

   SHOW max_connections;
2. Then, we can change the value of the `max_connections` parameter with the following command:

   ALTER SYSTEM SET max_connections = num_of_connections;

   Replace `num_of_connections` with the desired number of connections.
3. Now, restart the PostgreSQL server to apply the changes.
   • On Windows:

     Open the “Services” application. Then, locate the “postgresql” service and restart it.
   • On Linux:

     Run one of the following commands:

     sudo service postgresql restart
     Or,
     sudo systemctl restart postgresql
4. We can confirm that the new `max_connections` value has been applied by running:

   SHOW max_connections;

Optimizing Performance with shared_buffers

When increasing `max_connections`, our experts advise adjusting the `shared_buffers` parameter as well.

This setting decides how much memory PostgreSQL uses for shared memory buffers, which can impact performance.

We can use the `ALTER SYSTEM` command to set the `shared_buffers` parameter.

ALTER SYSTEM SET shared_buffers = buffer_size;

Replace `buffer_size` with the desired memory allocation.

Then, restart the PostgreSQL server again to apply this change.

Adjusting the `max_connections` parameter in PostgreSQL lets us handle more concurrent connections. Additionally, optimizing the `shared_buffers` parameter can further boost performance. With these steps, we can effectively manage and improve the PostgreSQL server’s capacity and performance.

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Conclusion

In brief, our Support Experts demonstrated how to adjust max_connections in PostgreSQL.