Database Ingestion and Replication general limitations and guidelines

• •Database Ingestion and Replication does not support the Cloud Hosted Agent, a runtime environment on a cloud platform, or a serverless runtime environment. Use a local Secure Agent installation.
• •If a Secure Agent in a runtime environment that is assigned to a database ingestion and replication task terminates, you cannot undeploy the associated ingestion and replication job, update the task to specify another runtime environment, and deploy the task again. In this situation, perform one of the following actions:
• - Assign a different Secure Agent to the runtime environment. Ensure that the new Secure Agent is running. Then restart the associated database ingestion and replication job.
• - Copy the task. In the task copy, specify another runtime environment that has an active Secure Agent. Then deploy the task and run the associated database ingestion and replication job.
• •Database Ingestion and Replication uses UTF-8 as the code page. If you select another code page type when defining a connection, Database Ingestion and Replication ignores it.
• •Database Ingestion and Replication assumes that each row in a source table is unique. Informatica recommends that source tables have primary keys. If a table doesn't have a primary key, Database Ingestion and Replication uses the values in all columns, except LOB columns, to uniquely identify each source row. In this case, each Update operation is processed as a Delete followed by an Insert on the target.
Note: If you change the source primary key and have an Amazon S3, Flat File, Google Cloud Storage, or Microsoft Azure Data Lake Storage target, Database Ingestion and Replication processes each Update operation as a Delete followed by an Insert on the target.
• •Database Ingestion and Replication uses the minimum source constraints needed for replication when generating target objects. If a source has a primary key, the job preferentially uses the primary key and no other constraint when creating the target object.
Source object properties that are not required for replication, such as for storage and partitioning, are not reflected on the target.
• •Because Data Ingestion and Replication seeks to maintain consistency between the source and target when replicating data, it does not add or recognize any constraints on the target, such as those for nullability, foreign keys, and defaults. Doing so could lead to inconsistencies between the source and target and potential replication errors. For example, errors could occur if the NOT NULL constraint is added to a target column that receives data from a nullable source column, or if the DEFAULT constraint is added to a target column that receives source data that doesn't match the default.
Note: If source constraints exist at the time of task deployment, they're not re-created at the target because they might not have existed previously when data was added to a source column and captured.
• •If you run multiple incremental load or combined initial and incremental load jobs against the same source database, you cannot move capture processing of some source tables from one job to another job or merge the jobs into a single job, without resynchronizing the source and target tables being processed by the new job. Each job maintains a unique recovery checkpoint. If you try to move capture processing of a table from one job to another job, the correct recovery information for that table is not maintained, potentially causing data loss or duplicate events on the target.
• •The log file names generated for initial load jobs are the combination of task name, schema name, and table name. If the resulting file name exceeds the maximum length allowed by your Secure Agent operating system, the file might not be created or might not be found. If you suspect that the file name could exceed the limits of your operating system, use a shorter task name to reduce the overall expected file name length.
• •If a combined initial and incremental load job captures an incremental insert change record during the initial unload phase, the job manufactures a delete for the same row to remove any duplicate that might have been obtained from the initial unload. This manufactured activity will be reflected in audit and soft delete apply modes.
• •Database Ingestion and Replication does not display error messages that are longer than 1024 characters in the user interface. Instead, Database Ingestion and Replication prompts you to view the log file with the error, which is automatically downloaded.
• •If a source column has a numeric data type that is not compatible with any numeric data type on the target, Database Ingestion and Replication maps the source column to a target varchar column.