> ## Documentation Index
> Fetch the complete documentation index at: https://docs.sqlbuild.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Diffing dbt builds

> Compare your dbt build against a production baseline with sqb dbt diff.

`sqb dbt diff` compares the relations your dbt build produces against a production baseline, so you can confirm dev matches prod before you promote. It resolves the production-shaped relations by compiling your dbt project at the configured [`[dbt.production_ref]`](/concepts/dbt-compatibility/overview#the-production-ref-block) git ref, then compares each model.

Every run requires exactly one comparison mode:

```bash theme={null}
sqb dbt diff --schema-only
sqb dbt diff --full
sqb dbt diff --bounded <value>
```

Running without a mode is an error.

## Modes

### `--schema-only`

Compares column names and types per model, without reading row data. Fast, needs no key, and works on any model:

```
     Model  stg_orders
       Key  <not used>
Comparison  schema-only

Schemas
- - - - -
No schema differences.
```

Use this as a cheap structural check: it catches added, dropped, or retyped columns across the build without scanning rows.

### `--full`

Compares rows. Full row comparison needs a key to align rows between the two sides, so each compared model must define `config.unique_key` in its dbt config:

```
error[C341]: dbt diff requires model 'agg_daily_revenue' to define config.unique_key for row comparison
  = help: Add unique_key to the dbt model config, or run sqb dbt diff --schema-only.
```

Add `unique_key` to the model config to enable a full row diff, or fall back to `--schema-only` for models without a natural key.

### `--bounded`

Compares only a recent window of rows instead of the whole table, using the model's SQLBuild cursor metadata. This keeps the comparison cheap on large relations. The value depends on the cursor kind:

* **Timestamp cursor:** a duration like `30d`, `12h`, or `15m` - compares the last N of time.
* **Integer cursor:** an integer bound.

```bash theme={null}
sqb dbt diff --bounded 30d
```

The model must define SQLBuild cursor metadata for `--bounded` to apply; without it, SQLBuild reports a configuration error pointing you to add cursor metadata or use another mode.

## On this topic

* [Configuration](/concepts/dbt-compatibility/overview#the-production-ref-block) - the `[dbt.production_ref]` git ref and schema-name override that diff resolves against.
* [Clone](/concepts/dbt-compatibility/clone) - copy or clone production relations into a target.
* [Testing](/concepts/dbt-compatibility/testing) - unit tests against dbt models.