# Migrate Self-managed PostgreSQL: Transactional workflows ## Summary Move PostgreSQL data from Self-managed PostgreSQL to Ample, one component at a time. Destination verified on Ample: an optimistic version check and an event row written in the same transaction, a stale update rejected, and a history query over the application-owned events (history=2 conflict=rejected). Source procedure: Take a logical backup with `pg_dump -Fc` as a role that can read all application objects. Not migrated automatically: Custom extensions, tablespaces, replication topology, superuser-only settings, and OS-level backups 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 source server until confirmed. Rollback: keep the source untouched until you confirm; nothing at the source is changed or deleted by this guide. ## Infrastructure requirements - [Postgres](/discover/primitive/postgres): verified (Managed PostgreSQL 16 runs in its own microVM and is auto-provisioned when an app needs a database and no DATABASE_URL is supplied.) ## Prerequisites - Authorized access to the Self-managed 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 ## Exact tested configuration - template: `node-22` - runtime: `node` - size: `s-1vcpu-1gb` - install: `npm install` - build: `npm run build --if-present` - start: `npm run start` ## Steps 1. **Inventory the source.** List what Self-managed PostgreSQL provides beyond the component you are moving. Out of scope here: Custom extensions, tablespaces, replication topology, superuser-only settings, and OS-level backups have no equivalent on the managed database. 2. **Source step 1.** Take a logical backup with `pg_dump -Fc` as a role that can read all application objects 3. **Source step 2.** Check the major version, installed extensions, tablespaces, and custom roles against the managed engine (PostgreSQL 16, no custom extensions verified) 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. ``` 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/transactional-workflows). 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 source server 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. ## Tested examples - **Express pattern fixture (destination)** (tests/deploy-canaries/express-patterns): Verified destination basis: transactional workflows. ## Success checks - destination app responds on its public URL (`/` on the live URL, expect ample canary express patterns) - transactional-workflows check from the destination example (`/p/transactional-workflows` on the live URL, expect see the pattern fixture checks) - 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 Self-managed 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: Custom extensions, tablespaces, replication topology, superuser-only settings and OS-level backups 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 Estimated 10.00 USD per month (size prices from pricing.toml at build revision a1b8c38919e59cd035ebabaced73cf84ece24371). - app server x1 `s-1vcpu-1gb`: 5.00 USD - managed PostgreSQL database x1 `s-1vcpu-1gb`: 5.00 USD Destination always-on monthly price of the tested sizes; apps auto-pause when idle. Source costs are unknown to Ample. ## Verification evidence - canary_run on 2026-09-21T02:34:39Z at revision `1d28ae0-dirty (CLI 0.1.21)`: 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 (an optimistic version check and an event row written in the same transaction, a stale update rejected, and a history query over the application-owned events (history=2 conflict=rejected)). The source-side export from Self-managed PostgreSQL is documented from the vendor's standard tooling and was not executed by this catalog's evidence. (expires 2027-03-20T02:34:39Z) Last verified: 2026-09-21T02:34:39Z ## Execution binding No execution binding. This recipe is documentation only; nothing is executed automatically.