docsp-31169 - change stream schema inference (#164)

Co-authored-by: Caitlin Davey <[email protected]>

Author: mongoKart

snooty.toml

@@ -6,8 +6,8 @@ intersphinx = ["https://www.mongodb.com/docs/manual/objects.inv"]
 toc_landing_pages = ["configuration"]
 
 [constants]
-driver-short = "Spark Connector"
-driver-long = "MongoDB {+driver-short+}"
+connector-short = "Spark Connector"
+connector-long = "MongoDB {+connector-short+}"
 current-version = "10.2.0"
 artifact-id-2-13 = "mongo-spark-connector_2.13"
 artifact-id-2-12 = "mongo-spark-connector_2.12"

source/configuration/read.txt

@@ -133,7 +133,7 @@ You can configure the following properties to read from MongoDB:
 Partitioner Configurations
 ~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-Partitioners change the read behavior for batch reads with the {+driver-short+}.
+Partitioners change the read behavior for batch reads with the {+connector-short+}.
 They do not affect Structured Streaming because the data stream processing
 engine produces a single stream with Structured Streaming.
 
@@ -330,9 +330,13 @@ Change Streams
      - | Specifies whether to publish the changed document or the full
          change stream document.
        |
-       | When set to ``true``, the connector filters out messages that
+       | When this setting is ``true``, the connector exhibits the following behavior:
+       
+       - The connector filters out messages that
          omit the ``fullDocument`` field and only publishes the value of the
          field.
+       - If you don't specify a schema, the connector infers the schema
+         from the change stream document rather than from the underlying collection.
 
        .. note::
 

source/read-from-mongodb.txt

@@ -42,6 +42,18 @@ Overview
 
          .. include:: /scala/filters.txt
 
+.. important:: Inferring the Schema of a Change Stream
+
+   When the {+connector-short+} infers the schema of a data frame 
+   read from a change stream, by default,
+   it will use the schema of the underlying collection rather than that
+   of the change stream. If you set the ``change.stream.publish.full.document.only``
+   option to ``true``, the connector uses the schema of the 
+   change stream instead.
+
+   For more information on configuring a read operation, see the
+   :ref:`spark-change-stream-conf` section of the Read Configuration Options guide.
+
 SQL Queries
 -----------
 

source/structured-streaming.txt

@@ -191,7 +191,7 @@ Configuring a Write Stream to MongoDB
 
 Configuring a Read Stream from MongoDB
 --------------------------------------
-When reading a stream from a MongoDB database, the {+driver-long+} supports both 
+When reading a stream from a MongoDB database, the {+connector-long+} supports both 
 *micro-batch processing* and 
 *continuous processing*. Micro-batch processing is the default processing engine, while
 continuous processing is an experimental feature introduced in