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Migrating Oracle Data into SQL Server (OracleToSQL)

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After you have successfully synchronized the converted objects with SQL Server, you can migrate data from Oracle to SQL Server.

Important

If the engine being used is Server Side Data Migration Engine, then, before you can migrate data, you must install the SSMA for Oracle Extension Pack and the Oracle providers on the computer that is running SSMA. The SQL Server Agent service must also be running. For more information about how to install the extension pack, see Installing Server Components (OracleToSQL)

Note

While Microsoft Entra ID is the new name for Azure Active Directory (Azure AD), to prevent disrupting existing environments, Azure AD still remains in some hardcoded elements such as UI fields, connection providers, error codes, and cmdlets. In this article, the two names are interchangeable.

Setting Migration Options

Before migrating data to SQL Server, review the project migration options in the Project Settings dialog box.

  • By using this dialog box you can set options such as migration batch size, table locking, constraint checking, null value handling, and identity value handling. For more information about the Project Migration Settings, see Project Settings (Migration) (OracleToSQL).

  • The Migration Engine in the Project Settings dialog box, allows the user to perform the migration process using two types of data migration engines:

    1. Client Side Data Migration Engine

    2. Server Side Data Migration Engine

Client Side Data Migration:

  • To initiate data-migration on the client side, select the Client Side Data Migration Engine option in the Project Settings dialog box.

  • In Project Settings, the Client Side Data Migration Engine option is set.

    Note

    The Client-Side Data Migration Engine resides inside the SSMA application and is, therefore, not dependent on the availability of the extension pack.

Server Side Data Migration:

  • During the Server side data migration, the engine resides on the target database. It is installed through the extension pack. For more information on how to install the extension pack, see Installing Server Components on SQL Server

  • To initiate migration on the server side, select the Server Side Data Migration Engine option in the Project Settings dialog box.

Migrating Data to SQL Server

Migrating data is a bulk-load operation that moves rows of data from Oracle tables into SQL Server tables in transactions. The number of rows loaded into SQL Server in each transaction is configured in the project settings.

To view migration messages, make sure that the Output pane is visible. Otherwise, from the View menu, select Output.

To migrate data

  1. Verify the following:

    • The Oracle providers are installed on the computer that is running SSMA.

    • You have synchronized the converted objects with the SQL Server database.

  2. In Oracle Metadata Explorer, select the objects that contain the data that you want to migrate:

    • To migrate data for all schemas, select the check box next to Schemas.

    • To migrate data or omit individual tables, first expand the schema, expand Tables, and then select or clear the check box next to the table.

  3. To migrate data, two cases arise:

    Client Side Data Migration:

    • For performing Client Side Data Migration, select the Client Side Data Migration Engine option in the Project Settings dialog box.

    Server Side Data Migration:

    • Before performing data migration on the server side, ensure:

      1. The SSMA for Oracle Extension Pack is installed on the instance of SQL Server.

      2. The SQL Server Agent service is running on the instance of SQL Server.

    • For performing Server Side Data Migration, select the Server Side Data Migration Engine option in the Project Settings dialog box.

  4. Right-click Schemas in Oracle Metadata Explorer, and then click Migrate Data. You can also migrate data for individual objects or categories of objects: Right-click the object or its parent folder; select the Migrate Data option.

    Note

    If the SSMA for Oracle Extension Pack is not installed on the instance of SQL Server, and if Server Side Data Migration Engine is selected, then while migrating the data to the target database, the following error is encountered: 'SSMA Data Migration components were not found on SQL Server, server-side data migration will not be possible. Please check if Extension Pack is installed correctly'. Click Cancel to terminate the data migration.

  5. In the Connect to Oracle dialog box, enter the connection credentials, and then click Connect. For more information on connecting to Oracle, see Connect To Oracle (OracleToSQL)

    For connecting to the target database SQL Server, enter the connection credentials in the Connect to SQL Server dialog box, and click Connect. For more information on connecting to SQL Server, see Connect to SQL Server

    Messages will appear in the Output pane. When the migration is complete, the Data Migration Report appears. If any data did not migrate, click the row that contains the errors, and then click Details. When you are finished with the report, click Close. For more information on Data Migration Report, see Data Migration Report (SSMA Common)

Note

When SQL Express edition is used as the target database, only client side data migration is allowed and server side data migration is not supported.

Migrating data at scale (Preview)

When large data size needs to be migrated within a short duration, at scale offline migration is a suitable option. This feature uses the Azure data factory pipeline and the scalability of cloud to migrate on-premises or external Oracle data source to Azure SQL platform whether IaaS VM or SQL PaaS. This capability will create the data factory or use an existing data factory to migrate data to Azure SQL PaaS or SQL VM.

  1. For large offline migration, click on Migrate data at scale.

  2. Provide Microsoft Entra/Azure AD account for authentication. Once you enter the username, select Connect.

  3. Select the tenant and the subscription that already has the Azure SQL VM or Azure SQL database or managed instance configured and click next.

  4. The next step in the migrate workflow is to provide the data source credentials followed by the target SQL credentials.

  5. For this migration, either you can use existing Azure resources - resource group and the data factory name or click new to create a resource group and Azure data factory for migration.

  6. In order to migrate an external data source, an integration runtime is required. Either click new and follow the steps to create the integration runtime or use an existing integration service. To create an integration service, a gateway installation needs to be configured and a key needs to be supplied to configure integration runtime.

  7. Finally, provide a unique data migration name. Migration name supports characters and numeric values. Avoid any special characters.

  8. If the target tables contain data, it will be truncated and reloaded. A warning dialog box will appear. Select OK to proceed or cancel to avoid truncate and load activity.

  9. It takes few minutes to create Azure data factory components. The status bar will provide the progress of the pipeline creation. If the pipeline is created successfully, a message will be written in the output log "A data factory pipeline [PipelineName] is created for the data migration activity."

  10. For monitoring the data migration, click on the monitoring URL or go to the data factory monitoring page in Azure portal.

See Also

Migrating Oracle Databases to SQL Server (OracleToSQL)