diff --git a/tests/pytest/update/allow_update.py b/tests/pytest/update/allow_update.py
new file mode 100644
index 0000000000..cc6fab5fc5
--- /dev/null
+++ b/tests/pytest/update/allow_update.py
@@ -0,0 +1,67 @@
+# For step 1, we set all the values as 1
+# for step 2, we set all the values as 2
+# and so on
+# check query result here means not
+
+# clear env set up
+
+# create database db update 1
+
+# create table t (ts timestamp, a int)
+
+# set an init time (such as $t0 = 1604295582000)
+
+# Step 1
+insert into t values ($t0, 1);
+insert into t values ($t0 - 3, 1);
+insert into t values ($t0 + 3, 1);
+
+check query result
+
+# Step 2
+insert into t values ($t0, 2);
+insert into t values ($t0 - 3, 2);
+insert into t values ($t0 + 3, 2);
+
+check query result
+
+# Step 3
+insert into t values ($t0 - 4, 3);
+insert into t values ($t0 - 2, 3);
+insert into t values ($t0 + 2, 3);
+insert into t values ($t0 + 4, 3);
+
+check query result
+
+# Step 4
+insert into t values ($t0 - 4, 4);
+insert into t values ($t0 - 2, 4);
+insert into t values ($t0 + 2, 4);
+insert into t values ($t0 + 4, 4);
+
+check query result
+
+# Step 4
+insert into t values ($t0 - 1, 5);
+insert into t values ($t0 + 1, 5);
+
+check query result
+
+# Step 4
+insert into t values ($t0 - 4, 6);
+insert into t values ($t0 - 3, 6);
+insert into t values ($t0 - 2, 6);
+insert into t values ($t0 - 1, 6);
+insert into t values ($t0, 6);
+insert into t values ($t0 + 1, 6);
+insert into t values ($t0 + 2, 6);
+insert into t values ($t0 + 3, 6);
+insert into t values ($t0 + 4, 6);
+
+check query result
+
+# Step 4
+
+restart to commit
+
+check query result
\ No newline at end of file
diff --git a/tests/pytest/update/append_commit_data.py b/tests/pytest/update/append_commit_data.py
new file mode 100644
index 0000000000..c907acb932
--- /dev/null
+++ b/tests/pytest/update/append_commit_data.py
@@ -0,0 +1,33 @@
+# clear env set up
+
+create database db update 1
+$t0 = 1604298064000
+
+## Step 1
+create table t1 (ts timestamp, a int);
+
+for ($i = 0; $i < 200; $i++) {
+  insert into t1 values ($t0 + $i, 1);
+}
+
+restart to commit
+check query result
+
+for ($k = 1; $k <= 100; $k++) {
+  for ($i = 0; $i < 200; $i++) {
+    insert into t1 values ($t0 + $k * 200 $i, 1);
+  }
+
+  restart to commit
+  check query result
+}
+
+## Step 2
+create table t2 (ts timestamp, a int);
+
+for ($i = 0; $i < 20000; $i++) {
+  insert into t2 values ($t0 + $i, 1);
+}
+
+restart to commit
+check query result
\ No newline at end of file
diff --git a/tests/pytest/update/append_commit_last.py b/tests/pytest/update/append_commit_last.py
new file mode 100644
index 0000000000..9b31adccec
--- /dev/null
+++ b/tests/pytest/update/append_commit_last.py
@@ -0,0 +1,42 @@
+# clear env set up
+
+create database db update 1;
+
+## Step 1
+$loops = 1000
+#t0 = 1604298064000
+
+create table t1 (ts timestamp, a int);
+for ($i = 0; $i < $loops; $i++) {
+  insert into t1 values ($t0 + $i, 1);
+  restart to commit
+  check query result
+}
+
+## Step 2
+create table t2 (ts timestamp, a int);
+
+insert into t2 ($t0, 1);
+restart to commit
+check query result
+
+for ($i = 1; $i <= 150; $i++) {
+  insert into t2 values ($t0 + $i, 1);
+}
+restart to commit
+check query result
+
+## Step 3
+create table t3 (ts timestamp, a int);
+
+insert into t3 ($t0, 1);
+restart to commit
+check query result
+
+for ($i = 0; $i < 8; $i++) {
+  for ($j = 1; $j <= 10; $j++) {
+    insert into t3 values ($t0 + $i * 10 + $j , 1);
+  }
+}
+restart to commit
+check query result
\ No newline at end of file
diff --git a/tests/pytest/update/merge_commit_data.py b/tests/pytest/update/merge_commit_data.py
new file mode 100644
index 0000000000..e9e2596821
--- /dev/null
+++ b/tests/pytest/update/merge_commit_data.py
@@ -0,0 +1,206 @@
+# clear env set up
+
+$t0 = 1603152000000
+
+create database db update 1 days 30;
+
+## Step 1. UPDATE THE WHOLE DATA BLOCK REPEATEDLY
+create table t1 (ts timestamp, a int);
+for ($i = 0; $i < 200; $i++) {
+  insert into t1 values ($t0 + $i, 1);
+}
+
+restart to commit
+check query result
+
+for ($k = 0; $k < 10; $k++) {
+  for ($i = 0; $i < 200; $i++) {
+    insert into t1 values ($t0 + $i, 1);
+  }
+
+  check query result
+  restart to commit
+  check query result
+}
+
+## Step 2. PREPEND DATA
+create table t2 (ts timestamp, a int);
+for ($i = 0; $i < 200; $i++) {
+  insert into t2 values ($t0 + $i, 1);
+}
+
+restart to commit
+check query result
+
+for ($i = -100; $i < 0; $i++) {
+  insert into t2 values ($t0 + $i, 1);
+}
+
+check query result
+restart to commit
+check query result
+
+## Step 3. PREPEND MASSIVE DATA
+create table t3 (ts timestamp, a int);
+for ($i = 0; $i < 200; $i++) {
+  insert into t3 values ($t0 + $i, 1);
+}
+
+restart to commit
+check query result
+
+for ($i = -6000; $i < 0; $i++) {
+  insert into t3 values ($t0 + $i, 1);
+}
+
+check query result
+restart to commit
+check query result
+
+## Step 4. APPEND DATA
+create table t4 (ts timestamp, a int);
+for ($i = 0; $i < 200; $i++) {
+  insert into t4 values ($t0 + $i, 1);
+}
+
+restart to commit
+check query result
+
+for ($i = 0; $i < 100; $i++) {
+  insert into t4 values ($t0 + 200 + $i, 1);
+}
+
+check query result
+restart to commit
+check query result
+
+## Step 5. APPEND MASSIVE DATA
+create table t5 (ts timestamp, a int);
+for ($i = 0; $i < 200; $i++) {
+  insert into t5 values ($t0 + $i, 1);
+}
+
+restart to commit
+check query result
+
+for ($i = 0; $i < 6000; $i++) {
+  insert into t5 values ($t0 + 200 + $i, 1);
+}
+
+check query result
+restart to commit
+check query result
+
+## Step 6. UPDATE BLOCK IN TWO STEP
+create table t6 (ts timestamp, a int);
+for ($i = 0; $i < 200; $i++) {
+  insert into t6 values ($t0 + $i, 1);
+}
+
+restart to commit
+check query result
+
+for ($i = 0; $i < 100; $i++) {
+  insert into t6 values ($t0 + $i, 2);
+}
+
+check query result
+restart to commit
+check query result
+
+for ($i = 100; $i < 200; $i++) {
+  insert into t6 values ($t0 + $i, 2);
+}
+
+check query result
+restart to commit
+check query result
+
+## Step 7. UPDATE LAST HALF AND INSERT LITTLE DATA
+create table t7 (ts timestamp, a int);
+for ($i = 0; $i < 200; $i++) {
+  insert into t7 values ($t0 + $i, 1);
+}
+
+restart to commit
+check query result
+
+for ($i = 100; $i < 300; $i++) {
+  insert into t7 values ($t0 + $i, 2);
+}
+
+check query result
+restart to commit
+check query result
+
+## Step 8. UPDATE LAST HALF AND INSERT MASSIVE DATA
+create table t8 (ts timestamp, a int);
+for ($i = 0; $i < 200; $i++) {
+  insert into t8 values ($t0 + $i, 1);
+}
+
+restart to commit
+check query result
+
+for ($i = 100; $i < 6000; $i++) {
+  insert into t8 values ($t0 + $i, 2);
+}
+
+check query result
+restart to commit
+check query result
+
+## Step 9. UPDATE FIRST HALF AND PREPEND LITTLE DATA
+create table t9 (ts timestamp, a int);
+for ($i = 0; $i < 200; $i++) {
+  insert into t9 values ($t0 + $i, 1);
+}
+
+restart to commit
+check query result
+
+for ($i = -100; $i < 100; $i++) {
+  insert into t9 values ($t0 + $i, 2);
+}
+
+check query result
+restart to commit
+check query result
+
+## Step 10. UPDATE FIRST HALF AND PREPEND MASSIVE DATA
+create table t10 (ts timestamp, a int);
+for ($i = 0; $i < 200; $i++) {
+  insert into t10 values ($t0 + $i, 1);
+}
+
+restart to commit
+check query result
+
+for ($i = -6000; $i < 100; $i++) {
+  insert into t10 values ($t0 + $i, 2);
+}
+
+check query result
+restart to commit
+check query result
+
+## Step 11. UPDATE FIRST HALF AND APPEND MASSIVE DATA
+create table t11 (ts timestamp, a int);
+for ($i = 0; $i < 200; $i++) {
+  insert into t11 values ($t0 + $i, 1);
+}
+
+restart to commit
+check query result
+
+for ($i = 0; $i < 100; $i++) {
+  insert into t11 values ($t0 + $i, 2);
+}
+
+for ($i = 200; $i < 6000; $i++) {
+  insert into t11 values ($t0 + $i, 2);
+}
+
+check query result
+restart to commit
+check query result
\ No newline at end of file
diff --git a/tests/pytest/update/merge_commit_data2.py b/tests/pytest/update/merge_commit_data2.py
new file mode 100644
index 0000000000..e9dd084eb0
--- /dev/null
+++ b/tests/pytest/update/merge_commit_data2.py
@@ -0,0 +1,153 @@
+# clear env set up
+
+$t0 = 1603152000000
+
+create database db update 1 days 30;
+
+## Step 1. UPDATE TWO WHOLE DATA BLOCK REPEATEDLY
+create table t1 (ts timestamp, a int);
+for ($i = 0; $i < 200; $i++) {
+  insert into t1 values ($t0 + $i, 1);
+}
+
+restart to commit
+check query result
+
+for ($i = 0; $i < 200; $i++) {
+  insert into t1 values ($t0 + 5000 + $i, 1);
+}
+
+check query result
+restart to commit
+check query result
+
+for ($i = 0; $i < 200; $i++) {
+  insert into t1 values ($t0 + $i, 2);
+}
+for ($i = 0; $i < 200; $i++) {
+  insert into t1 values ($t0 + 5000 + $i, 1);
+}
+check query result
+restart to commit
+check query result
+
+## Step 2. INSERT IN MIDDLE LITTLE DATA REPEATEDLY
+create table t2 (ts timestamp, a int);
+for ($i = 0; $i < 200; $i++) {
+  insert into t2 values ($t0 + $i, 1);
+}
+restart to commit
+for ($i = 0; $i < 200; $i++) {
+  insert into t2 values ($t0 + 5000 + $i, 1);
+}
+restart to commit
+
+for ($k = 0; $k < 10; $k++) {
+  for ($i = 0; $i < 10; $i++) {
+    insert into t2 values ($t0 + 200 + $k * 10 + $i, 1);
+  }
+  check query result
+  restart to commit
+  check query result
+}
+
+## Step 3. INSERT IN MIDDLE AND UPDATE TWO BLOCKS
+create table t3 (ts timestamp, a int);
+for ($i = 0; $i < 200; $i++) {
+  insert into t3 values ($t0 + $i, 1);
+}
+restart to commit
+for ($i = 0; $i < 200; $i++) {
+  insert into t3 values ($t0 + 5000 + $i, 1);
+}
+restart to commit
+
+for ($i = 0; $i < 5200; $i++) {
+  insert into t3 values ($t0 + $i, 2);
+}
+check query result
+restart to commit
+check query result
+
+## Step 4. INSERT IN MIDDLE AND UPDATE FIRST HALF OF TWO BLOCKS
+create table t4 (ts timestamp, a int);
+for ($i = 0; $i < 200; $i++) {
+  insert into t4 values ($t0 + $i, 1);
+}
+restart to commit
+for ($i = 0; $i < 200; $i++) {
+  insert into t4 values ($t0 + 5000 + $i, 1);
+}
+restart to commit
+
+for ($i = 0; $i < 100; $i++) {
+  insert into t4 values ($t0 + $i, 2);
+}
+for ($i = 200; $i < 5000; $i++) {
+  insert into t4 values ($t0 + $i, 2);
+}
+for ($i = 0; $i < 100; $i++) {
+  insert into t4 values ($t0 + 5000 + $i, 2);
+}
+check query result
+restart to commit
+check query result
+
+## Step 5. INSERT IN MIDDLE AND UPDATE last HALF OF TWO BLOCKS
+create table t5 (ts timestamp, a int);
+for ($i = 0; $i < 200; $i++) {
+  insert into t5 values ($t0 + $i, 1);
+}
+restart to commit
+for ($i = 0; $i < 200; $i++) {
+  insert into t5 values ($t0 + 5000 + $i, 1);
+}
+restart to commit
+
+for ($i = 100; $i < 200; $i++) {
+  insert into t5 values ($t0 + $i, 2);
+}
+for ($i = 200; $i < 5000; $i++) {
+  insert into t5 values ($t0 + $i, 2);
+}
+for ($i = 100; $i < 200; $i++) {
+  insert into t5 values ($t0 + 5000 + $i, 2);
+}
+check query result
+restart to commit
+check query result
+
+## Step 6. INSERT MASSIVE DATA AND UPDATE ALL BLOCKS
+create table t6 (ts timestamp, a int);
+for ($i = 0; $i < 200; $i++) {
+  insert into t6 values ($t0 + $i, 1);
+}
+restart to commit
+for ($i = 0; $i < 200; $i++) {
+  insert into t6 values ($t0 + 5000 + $i, 1);
+}
+restart to commit
+
+for ($i = -1000; $i < 10000; $i++) {
+  insert into t6 values ($t0 + $i, 2);
+}
+check query result
+restart to commit
+check query result
+
+## Step 7. SPLIT DATA BLOCK
+create table t7 (ts timestamp, a int);
+for ($i = 0; $i < 200; $i++) {
+  insert into t7 values ($t0 + $i, 1);
+}
+for ($i = 0; $i < 200; $i++) {
+  insert into t7 values ($t0 + 5000 + $i, 1);
+}
+restart to commit
+
+for ($i = -1000; $i < 10000; $i++) {
+  insert into t7 values ($t0 + $i, 2);
+}
+check query result
+restart to commit
+check query result
\ No newline at end of file
diff --git a/tests/pytest/update/merge_commit_last.py b/tests/pytest/update/merge_commit_last.py
new file mode 100644
index 0000000000..9d832d8984
--- /dev/null
+++ b/tests/pytest/update/merge_commit_last.py
@@ -0,0 +1,187 @@
+# clear env set up
+
+$t0 = 1603152000000
+
+create database db update 1 days 30;
+
+## STEP 1: UPDATE THE LAST RECORD REPEATEDLY
+create table t1 (ts timestamp, a int);
+
+for ($i = 0; $i < 100; $i++) {
+  insert into t1 values ($t0, $i);
+
+  restart to commit
+  check query result
+}
+
+## STEP 2: UPDATE THE WHOLE LAST BLOCK
+create table t2 (ts timestamp, a int);
+for ($i = 0; $i < 50; $i++) {
+  insert into t2 values ($t0 + $i, 1);
+}
+restart to commit
+check query result
+
+for ($i = 0; $i < 50; $i++) {
+  insert into t2 values ($t0 + $i, 2);
+}
+
+check query result
+restart to commit
+check query result
+
+## STEP 3: UPDATE PART OF THE LAST BLOCK
+create table t3 (ts timestamp, a int);
+for ($i = 0; $i < 50; $i++) {
+  insert into t3 values ($t0 + $i, 1);
+}
+restart to commit
+check query result
+
+for ($i = 0; $i < 25; $i++) {
+  insert into t3 values ($t0 + $i, 2);
+}
+
+check query result
+restart to commit
+check query result
+
+for ($i = 25; $i < 50; $i++) {
+  insert into t3 values ($t0 + $i, 2);
+}
+
+check query result
+restart to commit
+check query result
+
+## STEP 4: UPDATE AND INSERT APPEND AT END OF DATA
+create table t4 (ts timestamp, a int);
+for ($i = 0; $i < 50; $i++) {
+  insert into t4 values ($t0 + $i, 1);
+}
+restart to commit
+check query result
+
+for ($i = 0; $i < 25; $i++) {
+  insert into t4 values ($t0 + $i, 2);
+}
+
+for ($i = 50; $i < 60; $i++) {
+  insert into t4 values ($t0 + $i, 2);
+}
+
+check query result
+restart to commit
+check query result
+
+## STEP 5: UPDATE AND INSERT PREPEND SOME DATA
+create table t5 (ts timestamp, a int);
+for ($i = 0; $i < 50; $i++) {
+  insert into t5 values ($t0 + $i, 1);
+}
+restart to commit
+check query result
+
+for ($i = -10; $i < 0; $i++) {
+  insert into t4 values ($t0 + $i, 2);
+}
+
+for ($i = 0; $i < 25; $i++) {
+  insert into t5 values ($t0 + $i, 2);
+}
+
+check query result
+restart to commit
+check query result
+
+for ($i = -10; $i < 0; $i++) {
+  insert into t4 values ($t0 + $i, 3);
+}
+
+for ($i = 25; $i < 50; $i++) {
+  insert into t5 values ($t0 + $i, 3);
+}
+
+check query result
+restart to commit
+check query result
+
+## STEP 6: INSERT AHEAD A LOT OF DATA
+create table t6 (ts timestamp, a int);
+for ($i = 0; $i < 50; $i++) {
+  insert into t6 values ($t0 + $i, 1);
+}
+restart to commit
+check query result
+
+for ($i = -1000; $i < 0; $i++) {
+  insert into t6 values ($t0 + $i, 2);
+}
+
+check query result
+restart to commit
+check query result
+
+## STEP 7: INSERT AHEAD A LOT AND UPDATE
+create table t7 (ts timestamp, a int);
+for ($i = 0; $i < 50; $i++) {
+  insert into t7 values ($t0 + $i, 1);
+}
+restart to commit
+check query result
+
+for ($i = -1000; $i < 25; $i++) {
+  insert into t7 values ($t0 + $i, 2);
+}
+
+check query result
+restart to commit
+check query result
+
+## STEP 8: INSERT AHEAD A LOT AND UPDATE
+create table t8 (ts timestamp, a int);
+for ($i = 0; $i < 50; $i++) {
+  insert into t8 values ($t0 + $i, 1);
+}
+restart to commit
+check query result
+
+for ($i = 25; $i < 6000; $i++) {
+  insert into t8 values ($t0 + $i, 2);
+}
+
+check query result
+restart to commit
+check query result
+
+## STEP 9: UPDATE ONLY MIDDLE
+create table t9 (ts timestamp, a int);
+for ($i = 0; $i < 50; $i++) {
+  insert into t9 values ($t0 + $i, 1);
+}
+restart to commit
+check query result
+
+for ($i = 20; $i < 30; $i++) {
+  insert into t9 values ($t0 + $i, 2);
+}
+
+check query result
+restart to commit
+check query result
+
+## STEP 10: A LOT OF DATA COVER THE WHOLE BLOCK
+create table t10 (ts timestamp, a int);
+for ($i = 0; $i < 50; $i++) {
+  insert into t10 values ($t0 + $i, 1);
+}
+restart to commit
+check query result
+
+for ($i = -4000; $i < 4000; $i++) {
+  insert into t10 values ($t0 + $i, 2);
+}
+
+check query result
+restart to commit
+check query result
\ No newline at end of file