[MINOR][DOCS][STRUCTURED STREAMING] Minor doc fixes around `DataFrameWriter` and `DataStreamWriter`

## What changes were proposed in this pull request?

Fixes a couple old references to `DataFrameWriter.startStream` to `DataStreamWriter.start

Author: Burak Yavuz <brkyvz@gmail.com>

Closes #13952 from brkyvz/minor-doc-fix.

2 files changed, 6 insertions, 6 deletions

diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/UnsupportedOperationChecker.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/UnsupportedOperationChecker.scala
index 689e016a5a..f6e32e29eb 100644
--- a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/UnsupportedOperationChecker.scala
+++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/UnsupportedOperationChecker.scala
@@ -30,7 +30,7 @@ object UnsupportedOperationChecker {
   def checkForBatch(plan: LogicalPlan): Unit = {
     plan.foreachUp {
       case p if p.isStreaming =>
-        throwError("Queries with streaming sources must be executed with write.startStream()")(p)
+        throwError("Queries with streaming sources must be executed with writeStream.start()")(p)
 
       case _ =>
     }
@@ -40,7 +40,7 @@ object UnsupportedOperationChecker {
 
     if (!plan.isStreaming) {
       throwError(
-        "Queries without streaming sources cannot be executed with write.startStream()")(plan)
+        "Queries without streaming sources cannot be executed with writeStream.start()")(plan)
     }
 
     // Disallow multiple streaming aggregations
@@ -154,7 +154,7 @@ object UnsupportedOperationChecker {
 
         case ReturnAnswer(child) if child.isStreaming =>
           throwError("Cannot return immediate result on streaming DataFrames/Dataset. Queries " +
-            "with streaming DataFrames/Datasets must be executed with write.startStream().")
+            "with streaming DataFrames/Datasets must be executed with writeStream.start().")
 
         case _ =>
       }
diff --git a/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/analysis/UnsupportedOperationsSuite.scala b/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/analysis/UnsupportedOperationsSuite.scala
index c21ad5e03a..6df47acaba 100644
--- a/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/analysis/UnsupportedOperationsSuite.scala
+++ b/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/analysis/UnsupportedOperationsSuite.scala
@@ -53,12 +53,12 @@ class UnsupportedOperationsSuite extends SparkFunSuite {
   assertNotSupportedInBatchPlan(
     "streaming source",
     streamRelation,
-    Seq("with streaming source", "startStream"))
+    Seq("with streaming source", "start"))
 
   assertNotSupportedInBatchPlan(
     "select on streaming source",
     streamRelation.select($"count(*)"),
-    Seq("with streaming source", "startStream"))
+    Seq("with streaming source", "start"))
 
 
   /*
@@ -70,7 +70,7 @@ class UnsupportedOperationsSuite extends SparkFunSuite {
   // Batch plan in streaming query
   testError(
     "streaming plan - no streaming source",
-    Seq("without streaming source", "startStream")) {
+    Seq("without streaming source", "start")) {
     UnsupportedOperationChecker.checkForStreaming(batchRelation.select($"count(*)"), Append)
   }