Migrate Google Cloud SQL for PostgreSQL: Relational records

Move PostgreSQL data from Google Cloud SQL for PostgreSQL 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 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 <database-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/relational-records).

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: relational records. Source Ref: tests/deploy-canaries/express-patterns

Success Checks

• Destination app responds on its public URL (/)
  • Expect: ample canary express patterns
• Relational records check from the destination example (/p/relational-records)
  • Expect: see the pattern fixture checks
• Data or object counts and checksums match the source
  • 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.

Cost Estimate

• Currency: USD
• Monthly Amount: 10.0
• Components:
  1. App Server: Size - s-1vcpu-1gb, Quantity - 1.0, Monthly Amount - 5.0
  2. 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.