> ## Documentation Index
> Fetch the complete documentation index at: https://planetscale.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Supported versions

> When creating a PlanetScale Postgres cluster, you can choose from any of the Postgres versions we support.

export const PostgresVersions = () => {
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      {JSON.stringify({
    '@context': 'https://schema.org',
    '@type': 'ItemList',
    itemListElement: [{
      '@type': 'ListItem',
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      item: {
        '@type': 'SoftwareApplication',
        name: 'PlanetScale Postgres',
        softwareVersion: '17.9',
        applicationCategory: 'Database',
        operatingSystem: 'Cloud'
      }
    }, {
      '@type': 'ListItem',
      position: 2,
      item: {
        '@type': 'SoftwareApplication',
        name: 'PlanetScale Postgres',
        softwareVersion: '18.3',
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<PostgresVersions />

PlanetScale Postgres supports versions 17 and 18 of Postgres.

Specifically, the following versions are currently supported:

* 17.9
* 18.3

New databases will be created using the latest version by default and we recommend sticking to that default, but you can choose an older version if you need to.

## Major version upgrades

PlanetScale doesn't currently offer in-place upgrades between major versions of Postgres. To upgrade from Postgres 17 to 18, create a new Postgres 18 database and perform an online migration from your existing PlanetScale Postgres 17 database using our [import guides](/postgres/imports/postgres-imports).

The same import process also applies if you're migrating from another provider such as RDS, Aurora, or a self-hosted Postgres instance. You can import into any supported major version regardless of where the source database is hosted.

## Benchmarking Postgres 17 vs 18

Our [Benchmarking Postgres 17 vs 18](https://planetscale.com/blog/benchmarking-postgres-17-vs-18) blog post covers sysbench `oltp_read_only` results across multiple EC2 instance types and I/O configurations.

* **Postgres 18's new `io_method=worker` default delivers the best overall read performance**, outperforming both `io_uring` and the legacy synchronous I/O in most scenarios.
* **Local NVMe disks dramatically outperform network-attached storage** (gp3, io2) regardless of Postgres version or I/O setting.

## What's new in Postgres 18

Postgres 18 builds on Postgres 17 with new features, changed defaults, and some deprecations. For full details, see the official [Postgres 18 release notes](https://www.postgresql.org/docs/18/release-18.html).

| Area                         | What Postgres 18 adds                                                                                                                                                                                           |
| :--------------------------- | :-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **I/O architecture**         | New asynchronous I/O (AIO) subsystem with `io_method` setting (`worker`, `io_uring`, `sync`); up to 3× faster reads in benchmarks                                                                               |
| **Vacuum**                   | Proactive page-freezing during regular vacuums, reducing the need for aggressive vacuum passes                                                                                                                  |
| **WAL / write throughput**   | Per-connection WAL and I/O statistics for finer-grained monitoring                                                                                                                                              |
| **Indexes**                  | Skip-scan lookups on multicolumn B-tree indexes; parallel GIN index builds; broader `OR`-clause index usage                                                                                                     |
| **`pg_upgrade`**             | Retains optimizer statistics through upgrades, reducing post-upgrade performance dips; parallel checks via `--jobs`; `--swap` flag                                                                              |
| **SQL / developer features** | Virtual generated columns (default); `uuidv7()` / `uuidv4()` functions; `OLD`/`NEW` in `RETURNING` for DML statements; temporal `PRIMARY KEY`/`UNIQUE`/`FOREIGN KEY` constraints (`WITHOUT OVERLAPS`, `PERIOD`) |
| **Authentication**           | OAuth 2.0 authentication; FIPS mode validation; TLS v1.3 cipher suite allowlisting; SCRAM passthrough for `postgres_fdw`/`dblink`; `md5` auth deprecated                                                        |
| **Logical replication**      | Write-conflict logging; parallel streaming for subscriptions by default; `pg_createsubscriber --all` for all databases; auto-invalidation of idle replication slots                                             |
| **Observability**            | `EXPLAIN ANALYZE` auto-shows buffer access and index-lookup counts; `ANALYZE (VERBOSE)` now reports WAL, CPU, and average read stats                                                                            |
| **Text processing**          | `PG_UNICODE_FAST` collation; `casefold()` function; `LIKE` over nondeterministic collations; full-text search uses cluster default collation provider                                                           |
| **Wire protocol**            | Protocol version 3.2 (first update since 2003); `libpq` still defaults to 3.0 for backward compatibility                                                                                                        |
| **Data checksums**           | On by default at `initdb` (off by default in 17)                                                                                                                                                                |