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

# Migration REST service

export const productName = "Atoti FRTB";

# Migration REST Service

The Migration REST Service can be used to assist in the migration to using {productName} with DirectQuery.

The REST service is available at: `host:port/frtb-starter/migrationHelper/`

The REST service contains the following components:

* [Data Migration](#data-migration)

## Security Configuration

The security configuration is handled by the `DQMigrationHelperServiceSecurityConfig` bean defined in the `SecurityConfig`. The default security config limits
the use of this service to only `ADMIN` use.

## Database Extraction

This service allows you to export {productName}'s data into a format that is ready for your database of choice.

This service can extract for the following databases:

* [ClickHouse](#clickhouse-export)
* [Snowflake](#snowflake-export)

### ClickHouse Export

To export data into a format ready to be loaded into ClickHouse, use the [Template export](#clickhouse-template-extraction).
If you want to customize the stores to export, use the [Custom export](#custom-clickhouse-extraction).

#### ClickHouse Template Extraction

***URL:*** `host:port/frtb-starter/migrationHelper/extractForDatabase/clickhouse`

***Request Type:*** `POST`

***Body:*** [LocalFileOutputHandler](#localfileoutputhandler)

```json theme={"languages":{"custom":["/engine/python-sdk/0.9/languages/pycon.tmLanguage.json"]}}
{
    "outputDirectory": "path/to/extraction/directory",
    "compressionType": "NONE"
}
```

#### Custom ClickHouse Extraction

A custom extraction can be provided to export specific stores and datastore schemas.

The following is the default configuration for the `/extract` REST service to extract data for a ClickHouse database:

```json theme={"languages":{"custom":["/engine/python-sdk/0.9/languages/pycon.tmLanguage.json"]}}
{
    "databaseType": "CLICKHOUSE",
    "onlyIncludeStarSchemaStores": true,
    "cubeSchemasToExport": ["StandardisedApproachCube"],
    "extraStores": [
        "DeskDescription",
        "FXRates",
        "LegalEntityParentChild", "BookParentChild",
        "TrancheOverrides", "ObligorOverrides", "RiskFactorDescriptionOverrides", "RRAOOverrides", "UnderlyingDescriptionOverrides"
        ],
    "storesToIgnore": ["BookHierarchy", "LegalEntityHierarchy"],
    "localFileOutputHandler" : {
        "outputDirectory": "path/to/extraction/directory",
        "compressionType": "NONE"
    }
}
```

### Snowflake Export

To export data into a format ready to be loaded into Snowflake, the [Template export](#snowflake-template-extraction) can be used.
If you would like to customize the stores to export, you can use the [Custom export](#custom-snowflake-extraction).

#### Snowflake Template Extraction

***URL:*** `host:port/frtb-starter/migrationHelper/extractForDatabase/snowflake`

***Request Type:*** `POST`

***Body:*** [LocalFileOutputHandler](#localfileoutputhandler)

```json theme={"languages":{"custom":["/engine/python-sdk/0.9/languages/pycon.tmLanguage.json"]}}
{
    "outputDirectory": "path/to/extraction/directory",
    "compressionType": "NONE"
}
```

#### Custom Snowflake Extraction

The following is the default configuration for the `/extract` REST service to extract data for a Snowflake database:

```json theme={"languages":{"custom":["/engine/python-sdk/0.9/languages/pycon.tmLanguage.json"]}}
{
    "databaseType": "SNOWFLAKE",
    "onlyIncludeStarSchemaStores": true,
    "cubeSchemasToExport": ["StandardisedApproachCube"],
    "extraStores": [
        "DeskDescription",
        "FXRates",
        "LegalEntityParentChild", "BookParentChild",
        "TrancheOverrides", "ObligorOverrides", "RiskFactorDescriptionOverrides", "RRAOOverrides", "UnderlyingDescriptionOverrides"
        ],
    "storesToIgnore": ["BookHierarchy", "LegalEntityHierarchy"],
    "localFileOutputHandler" : {
        "outputDirectory": "path/to/extraction/directory",
        "compressionType": "NONE"
    }
}
```

## Request Objects

The following objects are used in the requests to the endpoints in this REST service.

### `DatabaseExtractionDTO`

| Parameter                     | Description                                                                      |
| ----------------------------- | -------------------------------------------------------------------------------- |
| `databaseType`                | One of the supported databases (all uppercase).<br /> For example, "CLICKHOUSE". |
| `onlyIncludeStarSchemaStores` | If you want to export only the stores that are part of the Star Schema.          |
| `cubeSchemasToExport`         | The cube schemas you want to export.                                             |
| `extraStores`                 | Additional stores to export.                                                     |
| `storesToIgnore`              | Stores you do not want to include in the extraction.                             |
| `localFileOutputHandler`      | The output handler. This writes the results into the local file system.          |

### `LocalFileOutputHandler`

| Parameter         | Description                                                                                                           |
| ----------------- | --------------------------------------------------------------------------------------------------------------------- |
| `outputDirectory` | Where to output the CSV files. This directory must already exist because the extractor cannot create new directories. |
| `compressionType` | The compression to apply to the file.<br />Either “NONE” or “GZIP”.                                                   |