In some cases, the Integration Service cannot recover a workflow or task. You cannot recover a workflow or task under the following circumstances:
You change the number of partitions.
If you change the number of partitions after a session fails, the recovery session fails.
The interrupted task has a fail recovery strategy.
If you configure a Command or Session recovery to fail and continue the workflow recovery, the task is not recoverable.
Recovery storage file is missing.
The Integration Service fails the recovery session or workflow if the recovery storage file is missing from $PMStorageDir or if the definition of $PMStorageDir changes between the original and recovery run.
Recovery table is empty or missing from the target database.
The Integration Service fails a recovery session under the following circumstances:
You deleted the table after the Integration Service created it.
The session enabled for recovery failed immediately after the Integration Service removed the recovery information from the table.
You might get inconsistent data if you perform recovery under the following circumstances:
The sources or targets change after the initial session.
If you drop or create indexes or edit data in the source or target tables before recovering a session, the Integration Service may return missing or repeat rows.
The source or target code pages change after the initial session failure.
If you change the source or target code page, the Integration Service might return incorrect data. You can perform recovery if the code pages are two-way compatible with the original code pages.