Applying migration rules in AWS Schema Conversion Tool - AWS Schema Conversion Tool
Creating migration rulesExporting migration rules

Applying migration rules in AWS Schema Conversion Tool

Before you convert your schema with AWS SCT, you can set up migration rules. Migration rules in AWS SCT can do such transformations as change the data type of columns, move objects from one schema to another, and change the names of objects. For example, suppose that you have a set of tables in your source schema named test_TABLE_NAME. You can set up a rule that changes the prefix test_ to the prefix demo_ in the target schema.

Note

You can only create migration rules for different source and target database engines.

You can create migration rules that perform the following tasks:

  • Add, remove, or replace a prefix

  • Add, remove, or replace a suffix

  • Change column collation

  • Change data type

  • Change the length of char, varchar, nvarchar, and string data types

  • Move objects

  • Rename objects

You can create migration rules for the following objects:

  • Database

  • Schema

  • Table

  • Column

Creating migration rules

You can create migration rules and save the rules as part of your project. With your project open, use the following procedure to create migration rules.

To create migration rules

  1. On the View menu, choose Mapping view.

  2. In Server mappings, choose a pair of source and target servers.

  3. Choose New migration rule. The Transformation rules dialog box appears.

  4. Choose Add new rule. A new row is added to the list of rules.

  5. Configure your rule:

    1. For Name, enter a name for your rule.

    2. For For, choose the type of object that the rule applies to.

    3. For where, enter a filter to apply to objects before applying the migration rule. The where clause is evaluated by using a like clause. You can enter an exact name to select one object, or you can enter a pattern to select multiple objects.

      The fields available for the where clause are different depending on the type of the object. For example, if the object type is schema there is only one field available, for the schema name.

    4. For Actions, choose the type of migration rule that you want to create.

    5. Depending on the rule type, enter one or two additional values. For example, to rename an object, enter the new name of the object. To replace a prefix, enter the old prefix and the new prefix.

      For char, varchar, nvarchar, and string data types, you can change the data type length using the multiplication operator. For example, the %*4 value transforms the varchar(10) data type into varchar(40).

  6. After you have configured your migration rule, choose Save to save your rule. You can also choose Cancel to cancel your changes.

    The transformation rules dialog box

  7. After you are done adding, editing, and deleting rules, choose Save All to save all your changes.

  8. Choose Close to close the Transformation rules dialog box.

You can use the toggle icon to turn off a migration rule without deleting it. You can use the copy icon to duplicate an existing migration rule. You can use the pencil icon to edit an existing migration rule. You can use the delete icon to delete an existing migration rule. To save any changes you make to your migration rules, choose Save All.

Exporting migration rules

If you use AWS DMS to migrate your data from your source database to your target database, you can provide information about your migration rules to AWS DMS. For more information about tasks, see Working with AWS Database Migration Service replication tasks.

To export migration rules

  1. In the AWS Schema Conversion Tool, choose Mapping View on the View menu.

  2. In Migration rules, choose a migration rule and then choose Modify migration rule.

  3. Choose Export script for AWS DMS.

  4. Browse to the location where you want to save your script, and then choose Save. Your migration rules are saved as a JSON script that can be consumed by AWS DMS.