## Migrate Heroku Postgres: Multi-tenant relational data

Move PostgreSQL data from Heroku Postgres to Ample, one component at a time. Destination verified on Ample: a tenant column on every row and query, with a cross-tenant read returning nothing (tenant_isolation=ok).

### Source procedure
Take a logical backup with `heroku pg:backups:capture` and download it, or `pg_dump -Fc` against the credentials from `heroku pg:credentials:url`.

**Not migrated automatically**: Heroku Postgres followers, forks, rollback (PITR) and dataclips have no equivalent on the managed database.

### Cutover
Put the app in maintenance mode with the user's go-ahead, take the final backup, restore, validate, redeploy with the managed DATABASE_URL, keep the Heroku database until confirmed.

### Rollback
Keep the source untouched until you confirm; nothing at the source is changed or deleted by this guide.

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### Workflow Steps
1. **Inventory the source**  
   List what Heroku Postgres provides beyond the component you are moving. Out of scope here: Heroku Postgres followers, forks, rollback (PITR) and dataclips have no equivalent on the managed database.
   
2. **Source step 1**  
   Take a logical backup with `heroku pg:backups:capture` and download it, or `pg_dump -Fc` against the credentials from `heroku pg:credentials:url`
   
3. **Source step 2**  
   Check the Postgres major version and extensions against the managed engine (PostgreSQL 16)
   
4. **Source step 3**  
   Restore into a scratch managed database first and compare row counts
   
5. **Provision and restore**  
   Deploy the app once so a managed PostgreSQL 16 database exists (or create one with `ample database create --engine postgres`), then restore the dump with pg_restore using its connection string; keep migrations idempotent.
      ```shell
      ample database create --name  --engine postgres
      ```

6. **Validate before cutover**  
   Run the app's own checks and, for data, compare counts and checksums; the example checks are the pattern self-tests (/p/multi-tenant-relational-data).
   
7. **Cut over**  
   Put the app in maintenance mode with the user's go-ahead, take the final backup, restore, validate, redeploy with the managed DATABASE_URL, keep the Heroku database until confirmed.
   
8. **Rollback**  
   Point DNS or configuration back to the source. The source was never modified; deletion is a separate, user-executed step after validation.

### Limitations
- Documentation only: nothing is executed automatically and no execution binding is offered. 
- The source-side procedure is documented from Heroku Postgres's standard tooling and was not executed in this catalog's evidence; the destination side was verified with the pattern fixture. 
- No full source-product parity is claimed: Heroku Postgres followers, forks, rollback (PITR) and dataclips have no equivalent on the managed database. 
- Verified on the node-22 template at s-1vcpu-1gb; region, compliance and request-duration limits are unknown. 
- Managed PostgreSQL 16 only; extensions, connection limits and backup or restore procedures on the managed side are not verified beyond the pattern checks.

### Cost Estimate
- Currency: USD
- Monthly Amount: 10.0
- Basis: size prices from pricing.toml (loaded by the API) at build revision 1ac5595375130d45290090e82ed0f554ccd45405-dirty
  - Components: 
    - App server (s-1vcpu-1gb): $5.0
    - Managed PostgreSQL database (s-1vcpu-1gb): $5.0
- Note: Destination always-on monthly price of the tested sizes; apps auto-pause when idle. Source costs are unknown to Ample.

### Success Checks
- Destination app responds on its public URL: **Expected**: ample canary express patterns
- Multi-tenant-relational-data check from the destination example: **Expected**: see the pattern fixture checks
- Data or object counts and checksums match the source: **Expected**: operator comparison before cutover.

### Examples
- **Express pattern fixture (destination)**: Verified destination basis: multi-tenant relational data.
    - Source Reference: tests/deploy-canaries/express-patterns

### Last Verified At
- Date: 2026-09-21T02:34:39Z

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### Next Actions
- [Browse the catalog index](/v1/catalog)
- [Search published recipes by intent, stack and constraints](/v1/catalog/search)
- [Prepare a side-effect-free deployment plan for an authorized project](/v1/catalog/plan)