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Use the DQS Speller

  • Artikel

Applies to: SQL Server

The Data Quality Services (DQS) Speller checks the syntax, spelling, and sentence structure of string values in a domain. The Speller is a standalone, client-side feature that has no integration with server-side engines and no implications on current flows or statuses. The Speller identifies those string values that it considers to be potential errors, and then marks them with a red underscore in the same location in which you make other manual changes to domain values. These locations include:

  • The Manage Domain Values page of the Knowledge Discovery activity

  • The Domain Values page or the Term-Based Relations page of the Domain Management activity

  • The Manage and View results page of the Cleansing activity

The Speller only works on single domains with a data type of string. All values in a single domain that are of a string data type are sent to the speller for validation. The Speller does not work for a composite domain, and it does not work for domains of types other than string, mixed values (such as letters and numbers with no space), Roman numerals, single characters, and values that consist only of upper-case letters.

Before You Begin

Prerequisites

To run the Speller, you must have a knowledge base and a domain opened in the Knowledge Discovery or Domain Management activity; the Speller must be enabled for the domain and in the page where you are going to run it; and the language property must be specified for the domain.

Security

Permissions

You must have the dqs_kb_editor or the dqs_administrator role on the DQS_MAIN database to run the Speller.

Enable the Speller

  1. To enable the Speller in Data Quality Client, open the knowledge base in the Domain Management activity, select the desired domain, and click Enable Speller on the Domain Properties page. In Language, select the language to be used with the Speller.

  2. When the Speller is enabled in the domain properties, it is enabled in the Manage Domain Values page, the Domain Values page or the Term-Based Relations page, and the Manage and View results page. To disable the Speller on these pages, click the Enable/Disable Speller icon. Clicking the icon changes the status of the Speller on the page. Likewise, if the Enable Speller property for the domain is disabled, clicking the Enable/Disable Speller icon enables the Speller on the page. If you exit the page and then return to it, the button status is again determined by the Enable Speller domain property.

Use the Speller

  1. Move to one of the following pages:

    • The Manage Domain Values page of the Knowledge Discovery activity

    • The Domain Values page or the Term-Based Relations page of the Domain Management activity

    • The Manage and View results page of the Cleansing activity

  2. Display the appropriate values in the Value table by filtering or searching.

  3. Scan the rows in the Value table to determine whether any value in the Value or Correct To columns is marked with a wavy red underscore.

  4. Right-click a value that is marked by a red underscore. Click one of the listed replacement values if it is preferable to the original value.

  5. If no displayed value is preferable, and there is a More suggestions button indicating additional values, click it. If one of the additional values is preferable to the original, click it.

  6. If you want to add the value to the dictionary, click Add to Dictionary. The red underscore will disappear from the value.

Follow Up: After Using the Speller

After you have run the Speller, complete the activity that the domain is in to use the corrections suggested by the Speller. If in the knowledge discovery, domain management, or matching policy activity, publish the knowledge base in order to make the results of the Speller analysis available for use in the knowledge base. For more information, see Perform Knowledge Discovery, Managing a Domain, or Create a Matching Policy.

How the Speller Works

The DQS Speller marks any potential string value error with a red underscore that is displayed for the entire value. For example, if "New York" is incorrectly spelled as "Neu York", the speller will display a red underscore under "Neu York", and not just "Neu". If you right-click the value, you will see suggested corrections for the whole value. You can also click More suggestions if there are more than five suggestions. You can pick one of the suggestions or add a value to the dictionary (at a user account level) to be displayed for the original value. Values added to the dictionary apply to all domains. Only if you explicitly designate a suggestion will the correction be made in the domain. When you select a suggestion from the Speller context menu, the value type becomes (or stays as) an error. The selected suggestion will be added to the correction column. Note that a value can have a Type of Correct and yet be marked as a potential error by the Speller.

DQS will provide suggestions for values in both the Value column and the Correct To column of the Value table. When you select a suggestion in the Value column, the value type is set to Error, and the suggestion is copied to the Correct To column, as if you inserted it manually. If there was an existing correction, it becomes a suggestion. In the Manage and View results page of the Cleansing activity, when you select a suggestion in the Correct To column, DQS will replace the currently selected value with the selection, and the currently selected value will become a suggestion. In the Manage and View results page of the Cleansing activity, no suggestions are made in the record-level (the lower grid).