create_execution makes gets one; an older execution without one reads the live
definition. A new execution is never read from the live definition, not even as a fallback when its snapshot is
missing.
The snapshot field
The backfill
A small number of public example workflows on blobhub.io had their historical executions given a snapshot from the definition as it stood on the day of the migration, marked"backfilled" rather than "created".
Where it’s used
- Download Execution Definition — the read path for a snapshot.
- Create Execution — when a snapshot is taken.