Learn how to easily handle the Postgres Docker ‘database files incompatible’ error. Our PostgreSQL Support team is here to help you with your questions and concerns.

How to Resolve Postgres Docker ‘database files incompatible’ Error

You’re not alone if you’ve run into the “database files are incompatible with server” error in your PostgreSQL container.

According to our Experts, this issue usually occurs when an updated PostgreSQL image is incompatible with the existing database files. PostgreSQL does not support automatic upgrades between major versions, so a version mismatch will cause this error.

This error usually occurs in the following scenarios:

• The previous PostgreSQL container ran an older major version (e.g., PostgreSQL 13), and the updated image ran a newer major version (e.g., PostgreSQL 15).
• PostgreSQL does not support direct upgrades between major versions without a proper migration plan.
• After updating the image, PostgreSQL tries to start with database files that are no longer compatible.

How to Resolve the Postgres Docker ‘database files incompatible’ Error

1. Clear the Old pgdata Volume

One of the common fixes is removing the old pgdata volume. Here’s how to do it:

# List your volumes
docker volume ls
# Remove the specific volume
docker volume rm volume-name
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This solution is useful when moving between different PostgreSQL versions, such as upgrading from `postgres:9.6` to `mdillon/postgis`. If we have been using a specific volume with an old PostgreSQL version, we need to delete it and recreate it to match the new PostgreSQL version.

2. Specify a PostgreSQL Version Explicitly

If we have used the `latest` tag when pulling PostgreSQL images, we might encounter compatibility issues when the `latest` version updates. Instead, explicitly specify the version to prevent automatic updates:

postgres:
image: postgres:12
restart: always
environment:
POSTGRES_USER: ${POSTGRES_USER}
POSTGRES_PASSWORD: ${POSTGRES_PASSWORD}
ports:
- "5432:5432"
volumes:
- db_data:/var/lib/postgresql/data
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By defining a specific PostgreSQL version (e.g., `postgres:12`), we can avoid unexpected upgrades that could break compatibility with our existing database files.

3. Roll Back and Restore Your Database

If we have already updated and run into this error, we can roll back to a previous PostgreSQL version and create a dump of our database:

# Dump your database
docker exec -it postgres-container-id pg_dump db_name %gt; local.dump.sql
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After verifying the dump file, follow these steps to restore it after upgrading PostgreSQL:

1. Remove the incompatible database volume.
2. Upgrade PostgreSQL to the desired version.
3. Restore the dump into a fresh database:
   

   
   # Create a new database
   psql -U postgres -d new_dbname -c "CREATE DATABASE new_dbname WITH OWNER postgres TEMPLATE template0;"
   # Restore the dump
   psql -U postgres -d new_dbname < local.dump.sql
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Before restoring, ensure all required users and permissions exist to prevent errors during the process.

4. Prune Unused Docker Volumes

If the system is cluttered with unused volumes, we can clean them up using:

docker volume pruneCopy Code

This command removes all unused volumes, those not associated with any active container.

Tips from our Experts

The “database files are incompatible with server” error in PostgreSQL is a common issue caused by version mismatches. To prevent and fix it:

• Always specify the PostgreSQL version explicitly.
• Plan for database migrations when upgrading PostgreSQL.
• Backup and restore data properly when switching versions.
• Remove old database volumes when necessary.

[Need assistance with a different issue? Our team is available 24/7.]

Conclusion

The above steps will smoothen the transition between PostgreSQL versions and prevent unexpected downtime in our applications.

In brief, our Support Experts demonstrated how to troubleshoot the Postgres Docker ‘database files incompatible’ error with ease.