Global rules are a useful way of making changes across multiple tables and columns in the same task. You can define transformation rules that modify the source data or metadata before it reaches the target, and/or you can define filter rules that determine which records will be replicated to the target.
Global rules are not available in a Log Stream Staging setup.
For information on Log Stream Staging,
Transformations - One way transformations can be used is to change the names of all tables in a task. You can change the names using wildcards and patterns. For example, you may want to change the names of the tables from account_% to ac_%. This is helpful when replicating data from a Microsoft SQL Server endpoint to an Oracle endpoint where the Microsoft SQL Server endpoint has a limit of 128 characters for a table name and the Oracle endpoint has a limit of 31 characters.
You may also need to change a specific data type in the source to a different data type in the target for many or all of the tables in the task. Global transformation will allow you to accomplish this without having to define a transformation for each individual table.Note:
Table-specific transformations override global transformations. For example, you can define a global transformation that changes the data type for all tables from DATE to DATETIME(6) and then define another transformation for a specific table that changes the data type from DATE to STRING(50).
For information on defining a transformation for a specific table, see Defining Transformations for a Single Table/View.
For an explanation of how to create global transformation, see Starting the Global Transformation Rules wizard.
Filters - Use filter rules to determine which records will be replicated to the target. Filter can be based on column data (e.g. only replicate records where Age is greater than 18) or record attributes (e.g. only replicate UPDATED records).
For an explanation of how to create global filters, see Starting the Global Filter Rules wizard.