<a id="cli-aws-dms-start-metadata-model-assessment"></a>

# start-metadata-model-assessment

## Description

Queues an assessment of the selected source metadata models (database objects such as tables, views, and procedures) to evaluate conversion complexity to the target database format. If other requests created by `Start*` operations are already in the migration project’s queue, the assessment begins after they complete.

The assessment request loads metadata models that are not yet in the metadata tree, but does not reload metadata models that are already present. If your source database has changed since the metadata was loaded, refresh the affected metadata models with [StartMetadataModelImport](https://docs.aws.amazon.com/dms/latest/APIReference/API_StartMetadataModelImport.html) before calling this operation.

To check the status of the assessment request, call [DescribeMetadataModelAssessments](https://docs.aws.amazon.com/dms/latest/APIReference/API_DescribeMetadataModelAssessments.html) using the returned `RequestIdentifier` as a filter.

To export the conversion assessment report after the request completes successfully, call [ExportMetadataModelAssessment](https://docs.aws.amazon.com/dms/latest/APIReference/API_ExportMetadataModelAssessment.html) .

> **Required permissions:**  `dms:StartMetadataModelAssessment` . For more information, see [Actions, resources, and condition keys for Database Migration Service](https://docs.aws.amazon.com/service-authorization/latest/reference/list_awsdatabasemigrationservice.html) .

See also: [AWS API Documentation](https://docs.aws.amazon.com/goto/WebAPI/dms-2016-01-01/StartMetadataModelAssessment)

## Synopsis

```
  start-metadata-model-assessment
--migration-project-identifier <value>
--selection-rules <value>
[--cli-input-json | --cli-input-yaml]
[--generate-cli-skeleton <value>]
[--debug]
[--endpoint-url <value>]
[--no-verify-ssl]
[--no-paginate]
[--output <value>]
[--query <value>]
[--profile <value>]
[--region <value>]
[--version <value>]
[--color <value>]
[--no-sign-request]
[--ca-bundle <value>]
[--cli-read-timeout <value>]
[--cli-connect-timeout <value>]
[--cli-binary-format <value>]
[--no-cli-pager]
[--cli-auto-prompt]
[--no-cli-auto-prompt]
[--cli-error-format <value>]
[--help]
```

## Options

`--migration-project-identifier` (string) [required]

> The migration project name or Amazon Resource Name (ARN).

> Constraints:

> * max: `255`

`--selection-rules` (string) [required]

> A JSON string that identifies the metadata models to assess. For the selection rule format and examples, see [Selection rules in DMS Schema Conversion](https://docs.aws.amazon.com/dms/latest/userguide/sc-selection-rules.html) .

> Usage:

> * Accepts only source selection rules, where `server-name` in the object locator matches the source data provider.
> * Supports `explicit` , `include` , and `exclude` rule actions.

`--cli-input-json` | `--cli-input-yaml` (string)
Reads arguments from the JSON string provided. The JSON string follows the format provided by `--generate-cli-skeleton`. If other arguments are provided on the command line, those values will override the JSON-provided values. It is not possible to pass arbitrary binary values using a JSON-provided value as the string will be taken literally. This may not be specified along with `--cli-input-yaml`.

`--generate-cli-skeleton` (string)
Prints a JSON skeleton to standard output without sending an API request. If provided with no value or the value `input`, prints a sample input JSON that can be used as an argument for `--cli-input-json`. Similarly, if provided `yaml-input` it will print a sample input YAML that can be used with `--cli-input-yaml`. If provided with the value `output`, it validates the command inputs and returns a sample output JSON for that command. The generated JSON skeleton is not stable between versions of the AWS CLI and there are no backwards compatibility guarantees in the JSON skeleton generated.

## Global Options

`--debug` (boolean)

Turn on debug logging.

`--endpoint-url` (string)

Override command’s default URL with the given URL.

`--no-verify-ssl` (boolean)

By default, the AWS CLI uses SSL when communicating with AWS services. For each SSL connection, the AWS CLI will verify SSL certificates. This option overrides the default behavior of verifying SSL certificates.

`--no-paginate` (boolean)

Disable automatic pagination. If automatic pagination is disabled, the AWS CLI will only make one call, for the first page of results.

`--output` (string)

The formatting style for command output.

* json
* text
* table
* yaml
* yaml-stream
* off

`--query` (string)

A JMESPath query to use in filtering the response data.

`--profile` (string)

Use a specific profile from your credential file.

`--region` (string)

The region to use. Overrides config/env settings.

`--version` (string)

Display the version of this tool.

`--color` (string)

Turn on/off color output.

* on
* off
* auto

`--no-sign-request` (boolean)

Do not sign requests. Credentials will not be loaded if this argument is provided.

`--ca-bundle` (string)

The CA certificate bundle to use when verifying SSL certificates. Overrides config/env settings.

`--cli-read-timeout` (int)

The maximum socket read time in seconds. If the value is set to 0, the socket read will be blocking and not timeout. The default value is 60 seconds.

`--cli-connect-timeout` (int)

The maximum socket connect time in seconds. If the value is set to 0, the socket connect will be blocking and not timeout. The default value is 60 seconds.

`--cli-binary-format` (string)

The formatting style to be used for binary blobs. The default format is base64. The base64 format expects binary blobs to be provided as a base64 encoded string. The raw-in-base64-out format preserves compatibility with AWS CLI V1 behavior and binary values must be passed literally. When providing contents from a file that map to a binary blob `fileb://` will always be treated as binary and use the file contents directly regardless of the `cli-binary-format` setting. When using `file://` the file contents will need to properly formatted for the configured `cli-binary-format`.

* base64
* raw-in-base64-out

`--no-cli-pager` (boolean)

Disable cli pager for output.

`--cli-auto-prompt` (boolean)

Automatically prompt for CLI input parameters.

`--no-cli-auto-prompt` (boolean)

Disable automatically prompt for CLI input parameters.

`--cli-error-format` (string)

The formatting style for error output. By default, errors are displayed in enhanced format.

* legacy
* json
* yaml
* text
* table
* enhanced

`--help` (boolean)

Display help for the command/subcommand.

## Examples

#### NOTE
To use the following examples, you must have the AWS CLI installed and configured. See the [Getting started guide](https://docs.aws.amazon.com/cli/latest/userguide/cli-chap-getting-started.html) in the *AWS CLI User Guide* for more information.

Unless otherwise stated, all examples have unix-like quotation rules. These examples will need to be adapted to your terminal’s quoting rules. See [Using quotation marks with strings](https://docs.aws.amazon.com/cli/latest/userguide/cli-usage-parameters-quoting-strings.html) in the *AWS CLI User Guide* .

**To assess all objects in a schema**

The following `start-metadata-model-assessment` example queues an assessment of the conversion complexity for all objects in the `ExampleSchema` schema.

```bash
aws dms start-metadata-model-assessment \
    --migration-project-identifier arn:aws:dms:us-west-2:123456789012:migration-project:EXAMPLEABCDEFGHIJKLMNOPQRS \
    --selection-rules '{"rules": [{"rule-type": "selection","rule-id": "1","rule-name": "1","object-locator": {"server-name": "example-source-server.us-west-2.rds.amazonaws.com", "schema-name": "ExampleSchema"},"rule-action": "explicit"}]}'
```

Output:

```json
{
    "RequestIdentifier": "a1b2c3d4-5678-90ab-cdef-EXAMPLE11111"
}
```

For more information, see [Creating database migration assessment reports](https://docs.aws.amazon.com/dms/latest/userguide/assessment-reports.html) in the *AWS Database Migration Service User Guide*.

## Output

RequestIdentifier -> (string)

> The identifier for the assessment request.