anchor.diff:  |Default
   |Description
   
  +|`operation.header`
  +|`false`
  +|The SMT adds the link:docs/connectors/mongodb/#change-events-value[event operation] as a message header
  +
   |`drop.tombstones`
   |`true`
   |The SMT removes the tombstone generated by Debezium from the stream.
  
positive.code: transforms.unwrap.type=io.debezium.connector.mongodb.transforms.UnwrapFromMongoDbEnvelope
  transforms.unwrap.drop.tombstones=false
  transforms.unwrap.delete.handling.mode=drop
  ----
  
  === Array encoding
  
negative.code: 
  This option allows you to convert a hierarchical document into a flat structure suitable for a table-like storage.
  
  === Determine original operation
  
  When a message is flattened the final result won't show whether it was an insert, update or first read (Deletions can be detected via tombstones or rewrites, see link:#configuration_options[Configuration options]).
  
  To solve this problem Debezium offers an option to propagate the original operation via a header added to the message.
  To enable this feature the option `operation.header` must be set to `true`.
  
  [source]
  ----
  transforms=unwrap,...
  transforms.unwrap.type=io.debezium.connector.mongodb.transforms.UnwrapFromMongoDbEnvelope
  transforms.unwrap.operation.header=true
  ----
  
  The possible values are the ones from the `op` field of link:docs/connectors/mongodb/#change-events-value[MongoDB connector change events].
  
  == Configuration options
  [cols="35%a,10%a,55%a",width=100,options="header,footer",role="table table-bordered table-striped"]
  |=======================
  