You can choose how Data Integration handles changes that you make to the data object schemas. To refresh the schema every time the mapping task runs, you can enable dynamic schema handling in the task.
A schema change includes one or more of the following changes to the data object:
•Fields added, deleted, or renamed.
•Fields updated for data type, precision, or scale.
Configure schema change handling on the Runtime Options page when you configure the task.
The following table describes the schema change handling options:
Option
Description
Asynchronous
Default. Data Integration refreshes the schema when you edit the mapping or mapping task, and when Informatica Intelligent Cloud Services is upgraded.
Dynamic
Data Integration refreshes the schema every time the task runs.
You can choose from the following options to refresh the schema:
- Alter and apply changes.Data Integration applies the following changes from the source schema to the target schema:
- New fields: Alters the target schema and adds the new fields from the source.
- Renamed fields: Adds renamed fields as new columns in the target.
- Data type and precision updates. Applies these changes to the target.
- Deleted fields: Ignores deleted fields.
- Don't apply DDL changes.Data Integration does not apply the schema changes to the target.
- Drop current and recreate. Drops the existing target table and then recreates the target table at runtime using all the incoming metadata fields from the source.
For more information, see the "Schema change handling" topic in Tasks in the Data Integration help.
Rules and guidelines for dynamic schema handling
Consider the following rules and guidelines when you enable dynamic schema change handling:
Mappings
- When you enable dynamic schema change handling, you cannot make changes to the columns of Uniqueidentifier data type.
- When you read data from or write data to a Microsoft Azure Synapse SQL and override the schema name or table name, do not use the Alter and apply changes or Drop current and recreate option.
- When you alter the datetime data type to another, Data Integration always maps the altered field to the datetime field in the Microsoft Azure Synapse SQL target.
For example, if you alter the source datetime field to datetime2, Data Integration maps the datetime2 field to datetime in the Microsoft Azure Synapse SQL target.
- When you read data from Microsoft Azure Synapse SQL, any table or column constraints in the source table are not retained in the target.
Mappings in advanced mode
- You cannot use schema change handling when you use a custom query as the source type.
- When you use the Drop current and recreate option, special characters in the column name are written as underscore in the target.