diff --git a/spanner/cloud-client/pom.xml b/spanner/cloud-client/pom.xml
index 687a5077991..d7f71c67fc9 100644
--- a/spanner/cloud-client/pom.xml
+++ b/spanner/cloud-client/pom.xml
@@ -42,7 +42,7 @@ limitations under the License.
       <dependency>
         <groupId>com.google.cloud</groupId>
         <artifactId>google-cloud-bom</artifactId>
-        <version>0.66.0-alpha</version>
+        <version>0.70.0-alpha</version>
         <type>pom</type>
         <scope>import</scope>
       </dependency>
diff --git a/spanner/cloud-client/src/main/java/com/example/spanner/SpannerSample.java b/spanner/cloud-client/src/main/java/com/example/spanner/SpannerSample.java
index a849df70887..c686118422a 100644
--- a/spanner/cloud-client/src/main/java/com/example/spanner/SpannerSample.java
+++ b/spanner/cloud-client/src/main/java/com/example/spanner/SpannerSample.java
@@ -19,6 +19,7 @@
 import static com.google.cloud.spanner.TransactionRunner.TransactionCallable;
 import static com.google.cloud.spanner.Type.StructField;
 
+import com.google.api.gax.longrunning.OperationFuture;
 import com.google.cloud.spanner.Database;
 import com.google.cloud.spanner.DatabaseAdminClient;
 import com.google.cloud.spanner.DatabaseClient;
@@ -26,10 +27,11 @@
 import com.google.cloud.spanner.Key;
 import com.google.cloud.spanner.KeySet;
 import com.google.cloud.spanner.Mutation;
-import com.google.cloud.spanner.Operation;
 import com.google.cloud.spanner.ReadOnlyTransaction;
 import com.google.cloud.spanner.ResultSet;
 import com.google.cloud.spanner.Spanner;
+import com.google.cloud.spanner.SpannerException;
+import com.google.cloud.spanner.SpannerExceptionFactory;
 import com.google.cloud.spanner.SpannerOptions;
 import com.google.cloud.spanner.Statement;
 import com.google.cloud.spanner.Struct;
@@ -42,6 +44,7 @@
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
+import java.util.concurrent.ExecutionException;
 import java.util.concurrent.TimeUnit;
 
 /**
@@ -56,6 +59,8 @@
  *   <li>Writing data using a read-write transaction.
  *   <li>Using an index to read and execute SQL queries over data.
  *   <li>Using commit timestamp for tracking when a record was last updated.
+ *   <li>Using Google API Extensions for Java to make thread-safe requests via
+ *       long-running operations. http://googleapis.github.io/gax-java/
  * </ul>
  */
 public class SpannerSample {
@@ -132,7 +137,7 @@ static class Performance {
 
   // [START spanner_create_database]
   static void createDatabase(DatabaseAdminClient dbAdminClient, DatabaseId id) {
-    Operation<Database, CreateDatabaseMetadata> op =
+    OperationFuture<Database, CreateDatabaseMetadata> op =
         dbAdminClient.createDatabase(
             id.getInstanceId().getInstance(),
             id.getDatabase(),
@@ -149,14 +154,24 @@ static void createDatabase(DatabaseAdminClient dbAdminClient, DatabaseId id) {
                     + "  AlbumTitle   STRING(MAX)\n"
                     + ") PRIMARY KEY (SingerId, AlbumId),\n"
                     + "  INTERLEAVE IN PARENT Singers ON DELETE CASCADE"));
-    Database db = op.waitFor().getResult();
-    System.out.println("Created database [" + db.getId() + "]");
+    try {
+      // Initiate the request which returns an OperationFuture.
+      Database db = op.get();
+      System.out.println("Created database [" + db.getId() + "]");
+    } catch (ExecutionException e) {
+      // If the operation failed during execution, expose the cause.
+      throw (SpannerException) e.getCause();
+    } catch (InterruptedException e) {
+      // Throw when a thread is waiting, sleeping, or otherwise occupied,
+      // and the thread is interrupted, either before or during the activity.
+      throw SpannerExceptionFactory.propagateInterrupt(e);
+    }
   }
   // [END spanner_create_database]
 
   // [START spanner_create_table_with_timestamp_column]
   static void createTableWithTimestamp(DatabaseAdminClient dbAdminClient, DatabaseId id) {
-    Operation<Void, UpdateDatabaseDdlMetadata> op =
+    OperationFuture<Void, UpdateDatabaseDdlMetadata> op =
         dbAdminClient.updateDatabaseDdl(
             id.getInstanceId().getInstance(),
             id.getDatabase(),
@@ -170,8 +185,18 @@ static void createTableWithTimestamp(DatabaseAdminClient dbAdminClient, Database
                     + ") PRIMARY KEY (SingerId, VenueId, EventDate),\n"
                     + "  INTERLEAVE IN PARENT Singers ON DELETE CASCADE"),
             null);
-    op.waitFor().getResult();
-    System.out.println("Created Performances table in database: [" + id + "]");
+    try {
+      // Initiate the request which returns an OperationFuture.
+      op.get();
+      System.out.println("Created Performances table in database: [" + id + "]");
+    } catch (ExecutionException e) {
+      // If the operation failed during execution, expose the cause.
+      throw (SpannerException) e.getCause();
+    } catch (InterruptedException e) {
+      // Throw when a thread is waiting, sleeping, or otherwise occupied,
+      // and the thread is interrupted, either before or during the activity.
+      throw SpannerExceptionFactory.propagateInterrupt(e);
+    }
   }
   // [END spanner_create_table_with_timestamp_column]
 
@@ -260,14 +285,25 @@ static void read(DatabaseClient dbClient) {
 
   // [START spanner_add_column]
   static void addMarketingBudget(DatabaseAdminClient adminClient, DatabaseId dbId) {
-    adminClient
-        .updateDatabaseDdl(
-            dbId.getInstanceId().getInstance(),
-            dbId.getDatabase(),
-            Arrays.asList("ALTER TABLE Albums ADD COLUMN MarketingBudget INT64"),
-            null)
-        .waitFor();
-    System.out.println("Added MarketingBudget column");
+    OperationFuture<Void, UpdateDatabaseDdlMetadata> op =
+        adminClient
+          .updateDatabaseDdl(
+              dbId.getInstanceId().getInstance(),
+              dbId.getDatabase(),
+              Arrays.asList("ALTER TABLE Albums ADD COLUMN MarketingBudget INT64"),
+              null);
+    try {
+      // Initiate the request which returns an OperationFuture.
+      op.get();
+      System.out.println("Added MarketingBudget column");
+    } catch (ExecutionException e) {
+      // If the operation failed during execution, expose the cause.
+      throw (SpannerException) e.getCause();
+    } catch (InterruptedException e) {
+      // Throw when a thread is waiting, sleeping, or otherwise occupied,
+      // and the thread is interrupted, either before or during the activity.
+      throw SpannerExceptionFactory.propagateInterrupt(e);
+    }
   }
   // [END spanner_add_column]
 
@@ -371,14 +407,25 @@ static void queryMarketingBudget(DatabaseClient dbClient) {
 
   // [START spanner_create_index]
   static void addIndex(DatabaseAdminClient adminClient, DatabaseId dbId) {
-    adminClient
-        .updateDatabaseDdl(
-            dbId.getInstanceId().getInstance(),
-            dbId.getDatabase(),
-            Arrays.asList("CREATE INDEX AlbumsByAlbumTitle ON Albums(AlbumTitle)"),
-            null)
-        .waitFor();
-    System.out.println("Added AlbumsByAlbumTitle index");
+    OperationFuture<Void, UpdateDatabaseDdlMetadata> op =
+        adminClient
+          .updateDatabaseDdl(
+              dbId.getInstanceId().getInstance(),
+              dbId.getDatabase(),
+              Arrays.asList("CREATE INDEX AlbumsByAlbumTitle ON Albums(AlbumTitle)"),
+              null);
+    try {
+      // Initiate the request which returns an OperationFuture.
+      op.get();
+      System.out.println("Added AlbumsByAlbumTitle index");
+    } catch (ExecutionException e) {
+      // If the operation failed during execution, expose the cause.
+      throw (SpannerException) e.getCause();
+    } catch (InterruptedException e) {
+      // Throw when a thread is waiting, sleeping, or otherwise occupied,
+      // and the thread is interrupted, either before or during the activity.
+      throw SpannerExceptionFactory.propagateInterrupt(e);
+    }
   }
   // [END spanner_create_index]
 
@@ -431,15 +478,27 @@ static void readUsingIndex(DatabaseClient dbClient) {
 
   // [START spanner_create_storing_index]
   static void addStoringIndex(DatabaseAdminClient adminClient, DatabaseId dbId) {
-    adminClient
-        .updateDatabaseDdl(
-            dbId.getInstanceId().getInstance(),
-            dbId.getDatabase(),
-            Arrays.asList(
-                "CREATE INDEX AlbumsByAlbumTitle2 ON Albums(AlbumTitle) STORING (MarketingBudget)"),
-            null)
-        .waitFor();
-    System.out.println("Added AlbumsByAlbumTitle2 index");
+    OperationFuture<Void, UpdateDatabaseDdlMetadata> op =
+        adminClient
+          .updateDatabaseDdl(
+              dbId.getInstanceId().getInstance(),
+              dbId.getDatabase(),
+              Arrays.asList(
+                  "CREATE INDEX AlbumsByAlbumTitle2 ON Albums(AlbumTitle) "
+                      + "STORING (MarketingBudget)"),
+              null); 
+    try {
+      // Initiate the request which returns an OperationFuture.
+      op.get();
+      System.out.println("Added AlbumsByAlbumTitle2 index");
+    } catch (ExecutionException e) {
+      // If the operation failed during execution, expose the cause.
+      throw (SpannerException) e.getCause();
+    } catch (InterruptedException e) {
+      // Throw when a thread is waiting, sleeping, or otherwise occupied,
+      // and the thread is interrupted, either before or during the activity.
+      throw SpannerExceptionFactory.propagateInterrupt(e);
+    }
   }
   // [END spanner_create_storing_index]
 
@@ -509,16 +568,27 @@ static void readStaleData(DatabaseClient dbClient) {
 
   // [START spanner_add_timestamp_column]
   static void addCommitTimestamp(DatabaseAdminClient adminClient, DatabaseId dbId) {
-    adminClient
-        .updateDatabaseDdl(
-            dbId.getInstanceId().getInstance(),
-            dbId.getDatabase(),
-            Arrays.asList(
-                "ALTER TABLE Albums ADD COLUMN LastUpdateTime TIMESTAMP "
-                    + "OPTIONS (allow_commit_timestamp=true)"),
-            null)
-        .waitFor();
-    System.out.println("Added LastUpdateTime as a commit timestamp column in Albums table.");
+    OperationFuture<Void, UpdateDatabaseDdlMetadata> op =
+        adminClient
+          .updateDatabaseDdl(
+              dbId.getInstanceId().getInstance(),
+              dbId.getDatabase(),
+              Arrays.asList(
+                  "ALTER TABLE Albums ADD COLUMN LastUpdateTime TIMESTAMP "
+                      + "OPTIONS (allow_commit_timestamp=true)"),
+              null); 
+    try {
+      // Initiate the request which returns an OperationFuture.
+      op.get();
+      System.out.println("Added LastUpdateTime as a commit timestamp column in Albums table.");
+    } catch (ExecutionException e) {
+      // If the operation failed during execution, expose the cause.
+      throw (SpannerException) e.getCause();
+    } catch (InterruptedException e) {
+      // Throw when a thread is waiting, sleeping, or otherwise occupied,
+      // and the thread is interrupted, either before or during the activity.
+      throw SpannerExceptionFactory.propagateInterrupt(e);
+    }
   }
   // [END spanner_add_timestamp_column]
 
@@ -605,8 +675,8 @@ static void queryPerformancesTable(DatabaseClient dbClient) {
             .singleUse()
             .executeQuery(
                 Statement.of(
-                    "SELECT SingerId, VenueId, EventDate, Revenue, LastUpdateTime FROM Performances"
-                        + " ORDER BY LastUpdateTime DESC"));
+                    "SELECT SingerId, VenueId, EventDate, Revenue, LastUpdateTime "
+                        + "FROM Performances ORDER BY LastUpdateTime DESC"));
     while (resultSet.next()) {
       System.out.printf(
           "%d %d %s %s %s\n",