Filtering within the replicator enables the information within the THL to be removed, augmented, or modified as the information is transferred within and between the replicators.
During filtering, the information in the THL can be modified in a host of different ways, including but not limited to:
Filtering out information based on the schema name, table name or column name. This is useful if you want a subset of the information in your target database, or if you want want to apply only certain columns to the information.
Filter information based on the content, or value of one or more fields.
Filter information based on the operation type, for example, only applying inserts to a target ignoring updates or deletes.
Modify or alter the format or structure of the data. This can be used to change the data format to be compatible with a target system, for example due to data type limitations, or sizes.
Add information to the data. For example, adding a database name, source name, or additional or compound fields into the target data. Within an analytics system this can be useful when combining data from multiple sources so that the source system or customer can still be identified.
The format, content, and structure of the data and the THL can be modified and new data can even be created through the filters.
For more information on the filters available, and how to use them, see Chapter 9, Replication Filters.