# Neon schema-only branches: test migrations without real data

## TL;DR

The standard advice for testing a migration is "branch prod and run it there." That puts a full copy of production data, PII included, in a branch that developers poke at. For migration testing you do not need the data at all; you need the schema. Neon supports schema-only branches: the branch carries the schema but no table data.

Use this when you run into the situation in the title.

## Steps

1. Create the branch as schema-only from the Console (or via the API's schema-only option).

   Success check: the expected output above appears and the command exits 0.

2. Run your migration against it.

   Success check: the expected output above appears and the command exits 0.

3. Verify the resulting schema with a diff against your expectation.

4. Delete the branch; it was cheap and disposable by design.

   Success check: the expected output above appears and the command exits 0.

## Compatibility

Tool: Neon. The steps above apply to the commands named in them. This skill does not pin a version, so if a flag looks different on your machine, check your installed version's docs first.

## Details

# Schema-only branches for migration testing

## The trap

## The rule

Use them when the goal is testing migrations or building new test data, not debugging production rows.

## When not to use it

Debugging a data-dependent bug needs real rows; use a normal branch there (and consider anonymization for PII). Load testing needs representative volume; schema-only gives you none.

## Checklist

- Migration CI jobs: schema-only branch, run migrate, diff, delete.
- Never put production PII in a branch just to test DDL.
- Pair with branch expiration so failed CI runs do not accumulate.