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

# Choose and Configure All Four Archery Storage Drivers

> Compare JSON files, SQLite, Postgres, and S3 storage; register migrations and required services; then select a DatabaseDisk for each model operation.

Archery database drivers back the shared `Model` API with four storage strategies; you will choose a disk, migrate models, and supply each driver's dependencies.

| Driver    | `DatabaseDisk` value | Identifier used by `find` | Recommended role                         |
| --------- | -------------------- | ------------------------- | ---------------------------------------- |
| JSON file | `.file`              | UUID string               | Local development and small applications |
| SQLite    | `.sqlite`            | Integer ID                | Small to medium applications             |
| Postgres  | `.pgsql`             | Integer ID                | Production workloads                     |
| S3 JSON   | `.s3`                | UUID string               | Backup, experimental, or niche storage   |

## Register migrations

The repository provides provider classes that migrate its bundled models during application boot.

```dart example/main.dart theme={null}
app.registerGroup('migrations', [
  SqliteMigrationsProvider(),
  // PgsqlMigrationsProvider(),
  // JsonFileModelsMigrationsProvider(),
  // S3MigrationsProvider(),
]);
```

For your own model, call the matching driver migration with its constructor. SQL drivers also accept column definitions.

<CodeGroup>
  ```dart lib/src/database/migrations/sqlite.dart theme={null}
  await SQLiteModel.migrate<Role>(
    constructor: Role.fromJson,
    columnDefinitions: Role.columnDefinitions,
  );
  ```

  ```dart lib/src/database/migrations/postgres.dart theme={null}
  await PostgresModel.migrate<Role>(
    constructor: Role.fromJson,
    columnDefinitions: Role.columnDefinitions,
  );
  ```

  ```dart lib/src/database/migrations/files.dart theme={null}
  await JsonFileModel.migrate<Role>(constructor: Role.fromJson);
  await S3JsonFileModel.migrate<Role>(constructor: Role.fromJson);
  ```
</CodeGroup>

## Select a driver

```dart lib/src/http/routes/users.dart theme={null}
final local = await Model.find<User>(id: 'uuid-value');
final sqlite = await Model.find<User>(id: 1, disk: .sqlite);
final postgres = await Model.find<User>(id: 1, disk: .pgsql);
final s3 = await Model.find<User>(id: 'uuid-value', disk: .s3);
```

SQLite and Postgres connections are registered during application boot from `db.sqlite` and `db.pgsql` configuration. S3 requires a registered `S3Client` and reads its storage configuration through `AppConfig`.

<Warning>
  Use the correct identifier type for the selected driver. File and S3 lookups use UUID strings, while SQLite and Postgres lookups use integer IDs.
</Warning>