[Docs] update data types doc and fix some typo

docs/.vuepress/sidebar/en.js

@@ -483,14 +483,15 @@ module.exports = [
             directoryPath: "Data Types/",
             children: [
               "BIGINT",
+              "BITMAP",
               "BOOLEAN",
               "CHAR",
               "DATE",
               "DATETIME",
               "DECIMAL",
               "DOUBLE",
               "FLOAT",
-              "HLL(HyperLogLog)",
+              "HLL",
               "INT",
               "SMALLINT",
               "TINYINT",

docs/.vuepress/sidebar/zh-CN.js

@@ -489,6 +489,7 @@ module.exports = [
             directoryPath: "Data Types/",
             children: [
               "BIGINT",
+              "BITMAP",
               "BOOLEAN",
               "CHAR",
               "DATE",

docs/en/sql-reference/sql-statements/Data Types/BITMAP.md

@@ -0,0 +1,48 @@
+---
+{
+    "title": "BITMAP",
+    "language": "en"
+}
+---
+
+<!-- 
+Licensed to the Apache Software Foundation (ASF) under one
+or more contributor license agreements.  See the NOTICE file
+distributed with this work for additional information
+regarding copyright ownership.  The ASF licenses this file
+to you under the Apache License, Version 2.0 (the
+"License"); you may not use this file except in compliance
+with the License.  You may obtain a copy of the License at
+
+  http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing,
+software distributed under the License is distributed on an
+"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+KIND, either express or implied.  See the License for the
+specific language governing permissions and limitations
+under the License.
+-->
+
+#BITMAP
+## Description
+BITMAP
+
+BITMAP cannot be used as a key column, and the aggregation type is BITMAP_UNION when building the table.
+The user does not need to specify the length and default value. The length is controlled within the system according to the degree of data aggregation.
+And the BITMAP column can only be queried or used by supporting functions such as bitmap_union_count, bitmap_union, and bitmap_hash.
+
+The use of BITMAP in offline scenarios will affect the import speed. In the case of a large amount of data, the query speed will be slower than HLL and better than Count Distinct.
+In the real-time scene, BITMAP cannot achieve complete and accurate deduplication, and the error is usually less than one thousandth.
+
+## example
+
+    select hour, BITMAP_UNION_COUNT(pv) over(order by hour) uv from(
+       select hour, BITMAP_UNION(device_id) as pv
+       from metric_table -- Query the accumulated UV per hour
+       where datekey=20200922
+    group by hour order by 1
+    ) final;
+
+## keyword
+BITMAP

docs/en/sql-reference/sql-statements/Data Types/HLL.md

@@ -0,0 +1,49 @@
+---
+{
+    "title": "HLL (HyperLogLog)",
+    "language": "en"
+}
+---
+
+<!-- 
+Licensed to the Apache Software Foundation (ASF) under one
+or more contributor license agreements.  See the NOTICE file
+distributed with this work for additional information
+regarding copyright ownership.  The ASF licenses this file
+to you under the Apache License, Version 2.0 (the
+"License"); you may not use this file except in compliance
+with the License.  You may obtain a copy of the License at
+
+  http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing,
+software distributed under the License is distributed on an
+"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+KIND, either express or implied.  See the License for the
+specific language governing permissions and limitations
+under the License.
+-->
+
+#HLL (HyperLogLog)
+## Description
+HLL
+
+HLL cannot be used as a key column, and the aggregation type is HLL_UNION when create table.
+The user does not need to specify the length and default value. 
+The length is controlled within the system according to the degree of data aggregation.
+And HLL columns can only be queried or used through the matching hll_union_agg, hll_raw_agg, hll_cardinality, and hll_hash.
+
+HLL is approximate count of distinct elements, and its performance is better than Count Distinct when the amount of data is large.
+The error of HLL is usually around 1%, sometimes up to 2%.
+
+## example
+
+    select hour, HLL_UNION_AGG(pv) over(order by hour) uv from(
+       select hour, HLL_RAW_AGG(device_id) as pv
+       from metric_table -- Query the accumulated UV per hour
+       where datekey=20200922
+    group by hour order by 1
+    ) final;
+
+## keyword
+HLL,HYPERLOGLOG

docs/en/sql-reference/sql-statements/Data Types/VARCHAR.md

@@ -27,7 +27,9 @@ under the License.
 # VARCHAR
 ## Description
 MARKETING (M)
-A variable length string, M represents the length of a variable length string. The range of M is 1-65535.
+A variable length string, M represents the length of a variable length string. The range of M is 1-65533.
+
+Note: Variable length strings are stored in UTF-8 encoding, so usually English characters occupies 1 byte, and Chinese characters occupies 3 bytes.
 
 ## keyword
 VARCHAR

docs/zh-CN/sql-reference/sql-statements/Data Types/BITMAP.md

@@ -0,0 +1,48 @@
+---
+{
+    "title": "BITMAP",
+    "language": "zh-CN"
+}
+---
+
+<!-- 
+Licensed to the Apache Software Foundation (ASF) under one
+or more contributor license agreements.  See the NOTICE file
+distributed with this work for additional information
+regarding copyright ownership.  The ASF licenses this file
+to you under the Apache License, Version 2.0 (the
+"License"); you may not use this file except in compliance
+with the License.  You may obtain a copy of the License at
+
+  http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing,
+software distributed under the License is distributed on an
+"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+KIND, either express or implied.  See the License for the
+specific language governing permissions and limitations
+under the License.
+-->
+
+# BITMAP
+## description
+    BITMAP
+    BITMAP不能作为key列使用，建表时配合聚合类型为BITMAP_UNION。
+    用户不需要指定长度和默认值。长度根据数据的聚合程度系统内控制。
+    并且BITMAP列只能通过配套的bitmap_union_count、bitmap_union、bitmap_hash等函数进行查询或使用。
+
+    离线场景下使用BITMAP会影响导入速度，在数据量大的情况下查询速度会慢于HLL，并优于Count Distinct。
+    实时场景下BITMAP也不能做到完全的精确去重，通常误差小于千分之一。
+
+## example
+
+    select hour, BITMAP_UNION_COUNT(pv) over(order by hour) uv from(
+       select hour, BITMAP_UNION(device_id) as pv
+       from metric_table -- 查询每小时的累计UV
+       where datekey=20200622
+    group by hour order by 1
+    ) final;
+
+## keyword
+
+    BITMAP

docs/zh-CN/sql-reference/sql-statements/Data Types/HLL.md

@@ -26,10 +26,22 @@ under the License.
 
 # HLL(HyperLogLog)
 ## description
-    VARCHAR(M)
-    变长字符串，M代表的是变长字符串的长度。M的范围是1-16385
-    用户不需要指定长度和默认值。长度根据数据的聚合程度系统内控制
-    并且HLL列只能通过配套的hll_union_agg、hll_raw_agg、hll_cardinality、hll_hash进行查询或使用
+    HLL
+    HLL不能作为key列使用，建表时配合聚合类型为HLL_UNION。
+    用户不需要指定长度和默认值。长度根据数据的聚合程度系统内控制。
+    并且HLL列只能通过配套的hll_union_agg、hll_raw_agg、hll_cardinality、hll_hash进行查询或使用。
+
+    HLL是模糊去重，在数据量大的情况性能优于Count Distinct。
+    HLL的误差通常在1%左右，有时会达到2%。
+
+## example
+
+    select hour, HLL_UNION_AGG(pv) over(order by hour) uv from(
+       select hour, HLL_RAW_AGG(device_id) as pv
+       from metric_table -- 查询每小时的累计UV
+       where datekey=20200622
+    group by hour order by 1
+    ) final;
 
 ## keyword
 

docs/zh-CN/sql-reference/sql-statements/Data Types/VARCHAR.md

@@ -27,7 +27,9 @@ under the License.
 # VARCHAR
 ## description
     VARCHAR(M)
-    变长字符串，M代表的是变长字符串的长度。M的范围是1-65535
+    变长字符串，M代表的是变长字符串的长度。M的范围是1-65533。
+
+    注意：变长字符串是以UTF-8编码存储的，因此通常英文字符占1个字节，中文字符占3个字节。
 
 ## keyword