PostgreSQL Compatibility
Neon is protocol and application-compatible with PostgreSQL. However, when using the Neon cloud service, there are some limitations that you should be aware of.
PostgreSQL versions
Neon cloud service is currently compatible with PostgreSQL 14 and PostgreSQL 15. You can select the PostgreSQL version you want to use when creating a Neon project. PostgreSQL 15 is selected, by default. For information about creating a Neon project, See Manage projects.
Permissions and extension support
The Neon cloud service does not currently provide roles with access permissions other than those granted to standard database owners in PostgreSQL. Therefore, Neon roles cannot access replication methods, create additional roles from a PostgreSQL connection, or install PostgreSQL extensions other than those permitted by Neon. For information about the PostgreSQL extensions that Neon supports, see PostgreSQL Extensions.
Neon PostgreSQL parameter settings
The following table lists Neon PostgreSQL parameter settings that may differ from the expected default.
| Parameter | Value | Note |
|---|---|---|
| fsync | off | Neon syncs data to the Neon Storage Engine to store your data safely and reliably |
| max_connections | The value depends on compute size. Set to 100 for Neon. | |
| shared_buffers | The value depends on compute size | |
| wal_level | replica | Logical replication is currently not supported |
note
You can use connection pooling in Neon to increase the number of supported connections. For more information, see Connection pooling.
Unlogged tables
Unlogged tables are maintained on Neon compute local storage. These tables do not survive compute restarts (including when a Neon compute instance is placed into an Idle state after a period of inactivity). This is unlike a standalone PostgreSQL installation, where unlogged tables are only truncated in the event of abnormal process termination. Additionally, unlogged tables are limited by compute local storage size.
Spill and index build handling
Certain queries in PostgreSQL can generate large datasets that do not fit in memory. In such cases, storage spills the data. In Neon, the size of compute local storage limits the ability to create large indexes or execute certain queries that generate large datasets.
Temporary tables
Temporary tables, which are stored in compute local storage, are limited by compute local storage size.
Session context
The Neon cloud service automatically closes idle connections after a period of inactivity, as described in Compute lifecycle. When connections are closed, anything defined within a session context is forgotten and must be recreated before being used again. For example, temporary tables, prepared statements, advisory locks, and notifications and listeners that were defined using the NOTIFY/LISTEN commands only exist for the duration of the current session and are lost when the session ends.
Statistics collection
Statistics collected by the PostgreSQL cumulative statistics system are currently not saved when the Neon compute node is placed into an Idle state due to inactivity or restarted. For information about the lifecycle of a Neon compute, see Compute lifecycle.
Need help?
Send a request to support@neon.tech, or join the Neon community forum.