diff --git a/doc/_toc.yml b/doc/_toc.yml
index 05f62d7..c1472e2 100644
--- a/doc/_toc.yml
+++ b/doc/_toc.yml
@@ -10,11 +10,19 @@ subtrees:
           - file: ch-system-design/exercise-wordcount
       - file: ch-datastream-api/index
         entries:
-          - file: ch-datastream-api/data-types
           - file: ch-datastream-api/skeleton
           - file: ch-datastream-api/transformations
+          - file: ch-datastream-api/data-types
           - file: ch-datastream-api/user-define-functions
           - file: ch-datastream-api/exercise-stock-basic
+      - file: ch-time-window/index
+        entries:
+          - file: ch-time-window/time
+          - file: ch-time-window/process-function
+          - file: ch-time-window/window
+          - file: ch-time-window/join
+          - file: ch-time-window/late-elements
+          - file: ch-time-window/exercise-stock
       - file: ch-state-checkpoint/index
         entries:
           - file: ch-state-checkpoint/checkpoint
@@ -24,18 +32,10 @@ subtrees:
       - file: ch-table-sql/index
         entries:
           - file: ch-table-sql/table-overview
-          - file: ch-table-sql/catalog-function
           - file: ch-table-sql/dynamic-table
+          - file: ch-table-sql/sql-window
           - file: ch-table-sql/sql-join
           - file: ch-table-sql/sql-ddl
           - file: ch-table-sql/system-function
-          - file: ch-table-sql/sql-window
-          - file: ch-table-sql/exercise-iot
-      - file: ch-time-window/index
-        entries:
-          - file: ch-time-window/join
-          - file: ch-time-window/late-elements
-          - file: ch-time-window/process-function
-          - file: ch-time-window/time
-          - file: ch-time-window/window
-          - file: ch-time-window/exercise-stock
\ No newline at end of file
+          - file: ch-table-sql/catalog-function
+          - file: ch-table-sql/exercise-iot
\ No newline at end of file
diff --git a/doc/ch-datastream-api/data-types.md b/doc/ch-datastream-api/data-types.md
index b693af3..b79a8a8 100644
--- a/doc/ch-datastream-api/data-types.md
+++ b/doc/ch-datastream-api/data-types.md
@@ -28,7 +28,7 @@ Flink支持上图所示的几种数据类型：基础类型、数组、复合类
 
 基础类型或其他对象类型组成的数组，如`String[]`。
 
-### 复合类型 {#composite-types}
+### 复合类型
 
 #### Scala case class
 
diff --git a/doc/ch-datastream-api/img/filter.drawio b/doc/ch-datastream-api/img/filter.drawio
new file mode 100644
index 0000000..afc7943
--- /dev/null
+++ b/doc/ch-datastream-api/img/filter.drawio
@@ -0,0 +1 @@
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\ No newline at end of file
diff --git a/doc/ch-datastream-api/img/flatMap.drawio b/doc/ch-datastream-api/img/flatMap.drawio
new file mode 100644
index 0000000..a20b9c7
--- /dev/null
+++ b/doc/ch-datastream-api/img/flatMap.drawio
@@ -0,0 +1 @@
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diff --git a/doc/ch-datastream-api/img/type-inference-process.drawio b/doc/ch-datastream-api/img/type-inference-process.drawio
new file mode 100644
index 0000000..18a0bf1
--- /dev/null
+++ b/doc/ch-datastream-api/img/type-inference-process.drawio
@@ -0,0 +1 @@
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