Umami Migration Failed (Prisma P3009 / P3018 Error)

How to fix it

Try these in order — the most common fix is first.

1. 1. Back up and free disk space first

   Copy steps
   1. Take a full database backup before touching migrations
   2. Check free disk space; large migrations need temporary space and can take 10+ minutes
   3. Resize the volume if it is near full
   Did this fix it? Yes No

2. 2. Retry the migration

   Copy steps
   1. Restart Umami once; some users report the remaining migrations then complete
   2. If you use a pooled DATABASE_URL, set DIRECT_DATABASE_URL to a direct PostgreSQL connection for migrations
   Did this fix it? Yes No

3. 3. Resolve the failed migration

   Copy steps
   1. Run npx prisma migrate status to see which migration failed
   2. If it made no changes, run npx prisma migrate resolve --rolled-back <migration_name>
   3. Run npx prisma migrate deploy again
   Did this fix it? Yes No

4. 4. Run the heavy migration manually in batches

   Copy steps
   1. Create helper indexes with CREATE INDEX CONCURRENTLY on website_event
   2. Apply the column/data changes from the migration SQL in batches (e.g. 2,000 rows at a time) instead of one UPDATE
   3. Mark it applied with npx prisma migrate resolve --applied <migration_name>
   4. Run npx prisma migrate deploy for the remaining migrations
   Did this fix it? Yes No

Symptoms

The build or container exits during check-db with 'migrate found failed migrations' (P3009), 'deadlock detected' (40P01) or a timeout, often on 09_update_hostname_region. Sometimes the disk fills up during the upgrade.

Why it happens

• Large website_event table makes the migration slow and lock-heavy
• Database instance too small (e.g. t3.micro) or out of disk space
• A previous attempt left a failed row in _prisma_migrations
• Connection pooler (pgbouncer) used for migrations instead of a direct connection
• MariaDB incompatibility with MySQL-specific functions in v2 migrations

This guide also covers

• umami migration failed
• umami p3009
• umami p3018
• umami check-db failed
• umami 09_update_hostname_region

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