DOCSP-41831: nested txnoptions struct

source/fundamentals/transactions.txt

@@ -54,12 +54,13 @@ instantiating a new client each time.
    Implementations of ``Session`` are not safe for concurrent use by multiple `goroutines
    <https://www.golang-book.com/books/intro/10>`__.
 
-Methods
--------
+Session Methods
+---------------
 
-After you start a session by using the ``StartSession()`` method, you can modify
-the session state by using the method set provided by the returned ``Session``. The
-following table describes these methods:
+After you start a session by using the ``StartSession()`` method on your
+client, you can modify the session state by using the method set
+provided by the returned ``Session``. The following table describes
+these methods:
 
 .. list-table::
    :widths: 25 75
@@ -127,6 +128,39 @@ A ``Session`` also has methods to retrieve session
 properties and modify mutable session properties. View the :ref:`API
 documentation <api-docs-transaction>` to learn more about these methods.
 
+.. _golang-session-txn-options:
+
+Session and Transaction Options
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+You can set options at the session level and the transaction level to
+customize how the driver performs a transaction. The following steps
+describe how to set options for all transactions run within a given
+``Session``:
+
+1. Create a ``TransactionOptions`` instance. You can specify options
+   such as a write concern, read concern, and read preference for all
+   transactions run in a given session.
+
+#. Create a ``SessionOptions`` instance by calling the
+   ``SetDefaultTransactionOptions()`` method, passing the
+   ``TransactionOptions`` instance as the parameter.
+
+   You can also specify other session options such as enabling causal
+   consistency.
+
+#. Pass the ``SessionOptions`` instance to the ``client.StartSession()``
+   method.
+
+The following code demonstrates how to specify session and transaction
+options, then create a session with these options:
+
+.. literalinclude:: /includes/fundamentals/code-snippets/transaction.go
+   :language: go
+   :dedent:
+   :start-after: begin-session-txn-options
+   :end-before: end-session-txn-options
+
 Example
 -------
 

source/includes/fundamentals/code-snippets/transaction.go

@@ -55,6 +55,15 @@ func main() {
 
 	fmt.Printf("Inserted _id values: %v\n", result)
 
+	// begin-session-txn-options
+	txnOpts := options.Transaction().SetReadConcern(readconcern.Majority())
+	sessOpts := options.Session().SetDefaultTransactionOptions(txnOpts)
+	session, err := client.StartSession(sessOpts)
+	if err != nil {
+		return err
+	}
+	// end-session-txn-options
+
 	// MANUAL TRANSACTION EXAMPLE
 	// uncomment this section to run this code
 

source/whats-new.txt

@@ -92,6 +92,12 @@ The 2.0 {+driver-short+} release includes the following improvements and fixes:
   contained the number of dropped indexes. See the
   :ref:`golang-remove-index` section of the Indexes guide to learn more.
 
+- You can set options for transactions run in a given session by
+  creating a ``TransactionOptions`` instance and passing the instance to
+  the ``SetDefaultTransactionOptions()`` method of ``SessionOptions``.
+  To learn more, see the :ref:`golang-session-txn-options` section of
+  the Transactions guide.
+
 .. _version-1.16:
 
 What's New in 1.16