# Migrate Amazon RDS for PostgreSQL: JSON Document Metadata

Move PostgreSQL data from Amazon RDS for PostgreSQL to Ample, one component at a time. Destination verified on Ample: a jsonb column with a GIN index queried by path and containment, with an aggregate over matching documents (json=ok).

## Source Procedure
Take a logical backup with `pg_dump -Fc` from a network location that can reach the instance. Not migrated automatically: Multi-AZ failover, read replicas, IAM authentication, PITR and Performance Insights have no equivalent on the managed database.

### Cutover
Freeze writes at the source with the user's go-ahead, take the final dump, restore, validate, redeploy with the managed DATABASE_URL, keep RDS until confirmed.

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

## Representative Queries
- Migrate Amazon RDS for PostgreSQL: JSON document metadata
- Where can I host JSON document metadata?
- I need a component-scoped export/import or reconfiguration procedure for JSON document metadata, 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.

## Workflow Steps
1. **Inventory the source**: List what Amazon RDS for PostgreSQL provides beyond the component you are moving. Out of scope here: Multi-AZ failover, read replicas, IAM authentication, PITR and Performance Insights have no equivalent on the managed database.
2. **Source step 1**: Take a logical backup with `pg_dump -Fc` from a network location that can reach the instance.
3. **Source step 2**: Check the engine major version, extensions and parameter-group settings the app depends on.
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/json-document-metadata).
7. **Cut over**: Freeze writes at the source with the user's go-ahead, take the final dump, restore, validate, redeploy with the managed DATABASE_URL, keep RDS 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 Amazon RDS for PostgreSQL'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: Multi-AZ failover, read replicas, IAM authentication, PITR and Performance Insights have no equivalent on the managed database.

## Cost Estimate
- **Monthly Amount**: $10.00 (USD)
  - **Breakdown**:
    - App server: 1 x s-1vcpu-1gb = $5.00
    - Managed PostgreSQL database: 1 x s-1vcpu-1gb = $5.00

## Examples
- **Express pattern fixture (destination)**: Verified destination basis: JSON document metadata.

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

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