Stream Schema Update Request
One or more fields that make up the primary key of a record
A numeric or datetime field by which to sort records for the purpose of deduplication.
Numeric fields must fit in a 64-bit signed integer datetime fields must use an ISO-8601 compatible format (https://www.ietf.org/rfc/rfc3339.txt).
Specifies how pre-existing records should be affected by a schema change.