# Migrate Google Cloud SQL for PostgreSQL: JSON document metadata

Move PostgreSQL data from Google Cloud SQL 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` through the Cloud SQL Auth Proxy or an authorized network. Not migrated automatically: Cloud SQL Auth Proxy/IAM authentication, high availability and PITR 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 Cloud SQL until confirmed. Rollback: keep the source untouched until you confirm; nothing at the source is changed or deleted by this guide.

## Workflow Steps

1. **Inventory the source**  
   List what Google Cloud SQL for PostgreSQL provides beyond the component you are moving. Out of scope here: Cloud SQL Auth Proxy/IAM authentication, high availability and PITR have no equivalent on the managed database.

2. **Source step 1**  
   Take a logical backup with `pg_dump -Fc` through the Cloud SQL Auth Proxy or an authorized network.

3. **Source step 2**  
   Check the engine major version, extensions and flags 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.  
   Command: `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/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 Cloud SQL 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: JSON document metadata.
   Source Reference: tests/deploy-canaries/express-patterns

## Success Checks

- **Destination app responds on its public URL**  
   Kind: http_get  
   Path: /  
   Expect: ample canary express patterns

- **json-document-metadata check from the destination example**  
   Kind: http_get  
   Path: /p/json-document-metadata  
   Expect: see the pattern fixture checks

- **Data or object counts and checksums match the source**  
   Kind: manual  
   Expect: operator comparison before cutover.

## Limitations

- Documentation only: nothing is executed automatically and no execution binding is offered.
- The source-side procedure is documented from Google Cloud SQL 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: Cloud SQL Auth Proxy/IAM authentication, high availability and PITR 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: size s-1vcpu-1gb, quantity 1.0, monthly amount 5.0  
  - Managed PostgreSQL database: size s-1vcpu-1gb, quantity 1.0, monthly amount 5.0  
- 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 (a jsonb column with a GIN index queried by path and containment, with an aggregate over matching documents (json=ok)). The source-side export from Google Cloud SQL for PostgreSQL is documented from the vendor's standard tooling and was not executed by this catalog's evidence.  
   Observed At: 2026-09-21T02:34:39Z  
   Implementation Revision: 1d28ae0-dirty (CLI 0.1.21)  
   Expires At: 2027-03-20T02:34:39Z  
   Scope: checks [/p/json-document-metadata], destination only, template node-22.

## Next Actions

- Browse the catalog index: GET /v1/catalog
- Search published recipes by intent, stack and constraints: POST /v1/catalog/search (body: {"limit":5,"query":"Migrate Google Cloud SQL for PostgreSQL: JSON document metadata"})
- Prepare a side-effect-free deployment plan for an authorized project: POST /v1/catalog/plan (body: {"inputs":{},"projectId":"","recipeId":"page:migrate:google-cloud-sql-for-postgresql:json-document-metadata","recipeRevision":"r1"})
- Read the existing agent authentication setup: GET /mcp/setup
- Browse Google Cloud SQL for PostgreSQL: GET /v1/catalog/nodes/migration%3Agoogle-cloud-sql-for-postgresql
- Browse JSON document metadata: GET /v1/catalog/nodes/pattern%3Ajson-document-metadata
- Browse Migrate Postgres: GET /v1/catalog/nodes/intent%3Amigrate-postgres