# Migrate Render PostgreSQL: JSON Document Metadata

Move PostgreSQL data from Render 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
1. Take a logical backup with `pg_dump -Fc` using the external connection string.
2. Not migrated automatically: Render's automatic backups and read replicas have no equivalent on the managed database.

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

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

## Prerequisites
- Authorized access to the Render PostgreSQL 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 Render PostgreSQL provides beyond the component you are moving. Out of scope here: Render's automatic backups and read replicas have no equivalent on the managed database.
2. **Source step 1**: Take a logical backup with `pg_dump -Fc` using the external connection string.
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, 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 with the user's go-ahead, take the final dump, restore, validate, redeploy with the managed DATABASE_URL, keep the Render 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.

## 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

## Limitations
- Documentation only: nothing is executed automatically and no execution binding is offered.
- The source-side procedure is documented from Render PostgreSQL's standard tooling and was not executed in this catalog's evidence; the destination side was verified with the pattern fixture.

## Cost Estimate
- **Monthly Amount**: $10.00  
  - app server: $5.00
  - managed PostgreSQL database: $5.00

## Example
**Express pattern fixture (destination)**: Verified destination basis: JSON document metadata.
- Source Reference: `tests/deploy-canaries/express-patterns`

## Evidence Summary
- Destination side verified: the Express pattern fixture deployed on Ample and its checks passed.

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

### 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
- Read the existing agent authentication setup
- Browse Render PostgreSQL
- Browse JSON document metadata
- Browse Migrate Postgres