# Migrate Heroku Postgres: Relational records

Move PostgreSQL data from Heroku Postgres to Ample, one component at a time. Destination verified on Ample: a workspace-scoped table, an explicit state machine (draft to review to published) that rejects invalid transitions, and a cross-workspace read that returns nothing (transitions=true isolation=true). 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.

## Representative Queries
- Migrate Heroku Postgres: Relational records
- Where can I host Relational records?
- I need a component-scoped export/import or reconfiguration procedure for Relational records, with compatibility checks, verification and rollback.

## Resource Requirements
- primitive:postgres

## Infrastructure Requirements
- **Postgres**: Managed PostgreSQL 16 runs in its own microVM and is auto-provisioned when an app needs a database and no DATABASE_URL is supplied.

## Workload
Relational records

## Migration Source
Heroku Postgres

## Prerequisites
- Authorized access to the Heroku Postgres source and its export tooling
- An inventory of every component in scope and out of scope
- A validated backup or copy before any cutover
- An Ample account token with servers:write, databases:read

## 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.
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/relational-records).
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.

## Examples
- **Express pattern fixture (destination)**: Verified destination basis: relational records. (sourceRef: tests/deploy-canaries/express-patterns)

## Success Checks
- Destination app responds on its public URL
- Relational-records check from the destination example
- Data or object counts and checksums match the source

## Limitations
- Documentation only: nothing is executed automatically and no execution binding is offered.
- Verified on the node-22 template at s-1vcpu-1gb; region, compliance and request-duration limits are unknown.

## Cost Estimate
- **Monthly Amount**: $10.00
- Components:  
  - **App Server**: size `s-1vcpu-1gb`, quantity 1.0, monthly amount $5.00
  - **Managed PostgreSQL Database**: size `s-1vcpu-1gb`, quantity 1.0, monthly amount $5.00  
- Note: Destination always-on monthly price of the tested sizes; apps auto-pause when idle. Source costs are unknown to Ample.

## Evidence Summary
- **Canary Run**: Destination side verified: the Express pattern fixture deployed on Ample (npm install, npm run build --if-present, npm run start on the node-22 template) and its checks passed.

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

## Unknowns
- Region availability is unknown until a verified region fact is recorded
- Compliance attestations are unknown; none are claimed.