Github user jackylk commented on a diff in the pull request:
https://github.com/apache/incubator-carbondata/pull/510#discussion_r95353328
--- Diff: docs/DML-Operations-on-Carbon.md ---
@@ -1,197 +1,308 @@
-<!--
- 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.
--->
-
-* [LOAD DATA](#LOAD DATA)
-* [SHOW SEGMENTS](#SHOW SEGMENTS)
-* [DELETE SEGMENT BY ID](#DELETE SEGMENT BY ID)
-* [DELETE SEGMENT BY DATE](#DELETE SEGMENT BY DATE)
-
-***
-
-# LOAD DATA
- This command loads the user data in raw format to the Carbon specific
data format store, this way Carbon provides good performance while querying the
data.Please visit [Data Management](Carbondata-Management.md) for more details
on LOAD
-
-### Syntax
-
- ```ruby
- LOAD DATA [LOCAL] INPATH 'folder_path' INTO TABLE [db_name.]table_name
- OPTIONS(property_name=property_value, ...)
- ```
-
-### Parameter Description
-
-| Parameter | Description | Optional |
-| ------------- | -----| -------- |
-| folder_path | Path of raw csv data folder or file. | NO |
-| db_name | Database name, if it is not specified then it uses current
database. | YES |
-| table_name | The name of the table in provided database.| NO |
-| OPTIONS | Extra options provided to Load | YES |
-
-
-### Usage Guideline
-Following are the options that can be used in load data:
-- **DELIMITER:** Delimiters can be provided in the load command.
-
- ``` ruby
- OPTIONS('DELIMITER'=',')
- ```
-- **QUOTECHAR:** Quote Characters can be provided in the load command.
-
- ```ruby
- OPTIONS('QUOTECHAR'='"')
- ```
-- **COMMENTCHAR:** Comment Characters can be provided in the load command
if user want to comment lines.
-
- ```ruby
- OPTIONS('COMMENTCHAR'='#')
- ```
-- **FILEHEADER:** Headers can be provided in the LOAD DATA command if
headers are missing in the source files.
-
- ```ruby
- OPTIONS('FILEHEADER'='column1,column2')
- ```
-- **MULTILINE:** CSV with new line character in quotes.
-
- ```ruby
- OPTIONS('MULTILINE'='true')
- ```
-- **ESCAPECHAR:** Escape char can be provided if user want strict
validation of escape character on CSV.
-
- ```ruby
- OPTIONS('ESCAPECHAR'='\')
- ```
-- **COMPLEX_DELIMITER_LEVEL_1:** Split the complex type data column in a
row (eg., a$b$c --> Array = {a,b,c}).
-
- ```ruby
- OPTIONS('COMPLEX_DELIMITER_LEVEL_1'='$')
- ```
-- **COMPLEX_DELIMITER_LEVEL_2:** Split the complex type nested data column
in a row. Applies level_1 delimiter & applies level_2 based on complex data
type (eg., a:b$c:d --> Array> = {{a,b},{c,d}}).
-
- ```ruby
- OPTIONS('COMPLEX_DELIMITER_LEVEL_2'=':')
- ```
-- **ALL_DICTIONARY_PATH:** All dictionary files path.
-
- ```ruby
- OPTIONS('ALL_DICTIONARY_PATH'='/opt/alldictionary/data.dictionary')
- ```
-- **COLUMNDICT:** Dictionary file path for specified column.
-
- ```ruby
- OPTIONS('COLUMNDICT'='column1:dictionaryFilePath1,
column2:dictionaryFilePath2')
- ```
- Note: ALL_DICTIONARY_PATH and COLUMNDICT can't be used together.
-- **DATEFORMAT:** Date format for specified column.
-
- ```ruby
- OPTIONS('DATEFORMAT'='column1:dateFormat1, column2:dateFormat2')
- ```
- Note: Date formats are specified by date pattern strings. The date
pattern letters in Carbon are
- the same as in JAVA
[SimpleDateFormat](http://docs.oracle.com/javase/7/docs/api/java/text/SimpleDateFormat.html).
-
-**Example:**
-
- ```ruby
- LOAD DATA local inpath '/opt/rawdata/data.csv' INTO table carbontable
- options('DELIMITER'=',', 'QUOTECHAR'='"',
'COMMENTCHAR'='#',
- 'FILEHEADER'='empno,empname,
- designation,doj,workgroupcategory,
-
workgroupcategoryname,deptno,deptname,projectcode,
-
projectjoindate,projectenddate,attendance,utilization,salary',
- 'MULTILINE'='true', 'ESCAPECHAR'='\',
- 'COMPLEX_DELIMITER_LEVEL_1'='$',
- 'COMPLEX_DELIMITER_LEVEL_2'=':',
-
'ALL_DICTIONARY_PATH'='/opt/alldictionary/data.dictionary',
- 'DATEFORMAT'='projectjoindate:yyyy-MM-dd'
- )
- ```
-
-***
-
-# SHOW SEGMENTS
-This command is to show the segments of carbon table to the user.
-
- ```ruby
- SHOW SEGMENTS FOR TABLE [db_name.]table_name LIMIT number_of_segments;
- ```
-
-### Parameter Description
-
-| Parameter | Description | Optional |
-| ------------- | -----| --------- |
-| db_name | Database name, if it is not specified then it uses current
database. | YES |
-| table_name | The name of the table in provided database.| NO |
-| number_of_segments | limit the output to this number. | YES |
-
-**Example:**
-
- ```ruby
- SHOW SEGMENTS FOR TABLE CarbonDatabase.CarbonTable LIMIT 2;
- ```
-
-***
-
-# DELETE SEGMENT BY ID
-
-This command is to delete segment by using the segment ID.
-
- ```ruby
- DELETE SEGMENT segment_id1,segment_id2 FROM TABLE [db_name.]table_name;
- ```
-
-### Parameter Description
-
-| Parameter | Description | Optional |
-| ------------- | -----| --------- |
-| segment_id | Segment Id of the load. | NO |
-| db_name | Database name, if it is not specified then it uses current
database. | YES |
-| table_name | The name of the table in provided database.| NO |
-
-**Example:**
-
- ```ruby
- DELETE SEGMENT 0 FROM TABLE CarbonDatabase.CarbonTable;
- DELETE SEGMENT 0.1,5,8 FROM TABLE CarbonDatabase.CarbonTable;
- ```
- Note: Here 0.1 is compacted segment sequence id.
-
-***
-
-# DELETE SEGMENT BY DATE
-This command will allow to deletes the Carbon segment(s) from the store
based on the date provided by the user in the DML command. The segment created
before the particular date will be removed from the specific stores.
-
- ```ruby
- DELETE SEGMENTS FROM TABLE [db_name.]table_name WHERE STARTTIME BEFORE
[DATE_VALUE];
- ```
-
-### Parameter Description
-
-| Parameter | Description | Optional |
-| ------------- | -----| ------ |
-| DATE_VALUE | Valid segement load start time value. All the segments
before this specified date will be deleted. | NO |
-| db_name | Database name, if it is not specified then it uses current
database. | YES |
-| table_name | The name of the table in provided database.| NO |
-
-**Example:**
-
- ```ruby
- DELETE SEGMENTS FROM TABLE CarbonDatabase.CarbonTable WHERE STARTTIME
BEFORE '2017-06-01 12:05:06';
- ```
-
-***
\ No newline at end of file
+<!--
+ 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.
+-->
+
+* [LOAD DATA](#LOAD DATA)
+* [SHOW SEGMENTS](#SHOW SEGMENTS)
+* [DELETE SEGMENT BY ID](#DELETE SEGMENT BY ID)
+* [DELETE SEGMENT BY DATE](#DELETE SEGMENT BY DATE)
+* [UPDATE CARBON TABLE](#UPDATE CARBON TABLE)
+* [DELETE RECORDS from CARBON TABLE](#DELETE RECORDS from CARBON TABLE)
+
+***
+
+# LOAD DATA
+ This command loads the user data in raw format to the Carbon specific
data format store, this way Carbon provides good performance while querying the
data.Please visit [Data Management](Carbondata-Management.md) for more details
on LOAD
+
+### Syntax
+
+ ```ruby
+ LOAD DATA [LOCAL] INPATH 'folder_path' INTO TABLE [db_name.]table_name
+ OPTIONS(property_name=property_value, ...)
+ ```
+
+### Parameter Description
+
+| Parameter | Description | Optional |
+| ------------- | -----| -------- |
+| folder_path | Path of raw csv data folder or file. | NO |
+| db_name | Database name, if it is not specified then it uses current
database. | YES |
+| table_name | The name of the table in provided database.| NO |
+| OPTIONS | Extra options provided to Load | YES |
+
+
+### Usage Guideline
+Following are the options that can be used in load data:
+- **DELIMITER:** Delimiters can be provided in the load command.
+
+ ``` ruby
+ OPTIONS('DELIMITER'=',')
+ ```
+- **QUOTECHAR:** Quote Characters can be provided in the load command.
+
+ ```ruby
+ OPTIONS('QUOTECHAR'='"')
+ ```
+- **COMMENTCHAR:** Comment Characters can be provided in the load command
if user want to comment lines.
+
+ ```ruby
+ OPTIONS('COMMENTCHAR'='#')
+ ```
+- **FILEHEADER:** Headers can be provided in the LOAD DATA command if
headers are missing in the source files.
+
+ ```ruby
+ OPTIONS('FILEHEADER'='column1,column2')
+ ```
+- **MULTILINE:** CSV with new line character in quotes.
+
+ ```ruby
+ OPTIONS('MULTILINE'='true')
+ ```
+- **ESCAPECHAR:** Escape char can be provided if user want strict
validation of escape character on CSV.
+
+ ```ruby
+ OPTIONS('ESCAPECHAR'='\')
+ ```
+- **COMPLEX_DELIMITER_LEVEL_1:** Split the complex type data column in a
row (eg., a$b$c --> Array = {a,b,c}).
+
+ ```ruby
+ OPTIONS('COMPLEX_DELIMITER_LEVEL_1'='$')
+ ```
+- **COMPLEX_DELIMITER_LEVEL_2:** Split the complex type nested data column
in a row. Applies level_1 delimiter & applies level_2 based on complex data
type (eg., a:b$c:d --> Array> = {{a,b},{c,d}}).
+
+ ```ruby
+ OPTIONS('COMPLEX_DELIMITER_LEVEL_2'=':')
+ ```
+- **ALL_DICTIONARY_PATH:** All dictionary files path.
+
+ ```ruby
+ OPTIONS('ALL_DICTIONARY_PATH'='/opt/alldictionary/data.dictionary')
+ ```
+- **COLUMNDICT:** Dictionary file path for specified column.
+
+ ```ruby
+ OPTIONS('COLUMNDICT'='column1:dictionaryFilePath1,
column2:dictionaryFilePath2')
+ ```
+ Note: ALL_DICTIONARY_PATH and COLUMNDICT can't be used together.
+- **DATEFORMAT:** Date format for specified column.
+
+ ```ruby
+ OPTIONS('DATEFORMAT'='column1:dateFormat1, column2:dateFormat2')
+ ```
+ Note: Date formats are specified by date pattern strings. The date
pattern letters in Carbon are
+ the same as in JAVA
[SimpleDateFormat](http://docs.oracle.com/javase/7/docs/api/java/text/SimpleDateFormat.html).
+
+**Example:**
+
+ ```ruby
+ LOAD DATA local inpath '/opt/rawdata/data.csv' INTO table carbontable
+ options('DELIMITER'=',', 'QUOTECHAR'='"',
'COMMENTCHAR'='#',
+ 'FILEHEADER'='empno,empname,
+ designation,doj,workgroupcategory,
+
workgroupcategoryname,deptno,deptname,projectcode,
+
projectjoindate,projectenddate,attendance,utilization,salary',
+ 'MULTILINE'='true', 'ESCAPECHAR'='\',
+ 'COMPLEX_DELIMITER_LEVEL_1'='$',
+ 'COMPLEX_DELIMITER_LEVEL_2'=':',
+
'ALL_DICTIONARY_PATH'='/opt/alldictionary/data.dictionary',
+ 'DATEFORMAT'='projectjoindate:yyyy-MM-dd'
+ )
+ ```
+
+***
+
+# SHOW SEGMENTS
+This command is to show the segments of carbon table to the user.
+
+ ```ruby
+ SHOW SEGMENTS FOR TABLE [db_name.]table_name LIMIT number_of_segments;
+ ```
+
+### Parameter Description
+
+| Parameter | Description | Optional |
+| ------------- | -----| --------- |
+| db_name | Database name, if it is not specified then it uses current
database. | YES |
+| table_name | The name of the table in provided database.| NO |
+| number_of_segments | limit the output to this number. | YES |
+
+**Example:**
+
+ ```ruby
+ SHOW SEGMENTS FOR TABLE CarbonDatabase.CarbonTable LIMIT 2;
+ ```
+
+***
+
+# DELETE SEGMENT BY ID
+
+This command is to delete segment by using the segment ID.
+
+ ```ruby
+ DELETE SEGMENT segment_id1,segment_id2 FROM TABLE [db_name.]table_name;
+ ```
+
+### Parameter Description
+
+| Parameter | Description | Optional |
+| ------------- | -----| --------- |
+| segment_id | Segment Id of the load. | NO |
+| db_name | Database name, if it is not specified then it uses current
database. | YES |
+| table_name | The name of the table in provided database.| NO |
+
+**Example:**
+
+ ```ruby
+ DELETE SEGMENT 0 FROM TABLE CarbonDatabase.CarbonTable;
+ DELETE SEGMENT 0.1,5,8 FROM TABLE CarbonDatabase.CarbonTable;
+ ```
+ Note: Here 0.1 is compacted segment sequence id.
+
+***
+
+# DELETE SEGMENT BY DATE
+This command will allow to deletes the Carbon segment(s) from the store
based on the date provided by the user in the DML command. The segment created
before the particular date will be removed from the specific stores.
+
+ ```ruby
+ DELETE SEGMENTS FROM TABLE [db_name.]table_name WHERE STARTTIME BEFORE
[DATE_VALUE];
+ ```
+
+### Parameter Description
+
+| Parameter | Description | Optional |
+| ------------- | -----| ------ |
+| DATE_VALUE | Valid segement load start time value. All the segments
before this specified date will be deleted. | NO |
+| db_name | Database name, if it is not specified then it uses current
database. | YES |
+| table_name | The name of the table in provided database.| NO |
+
+**Example:**
+
+ ```ruby
+ DELETE SEGMENTS FROM TABLE CarbonDatabase.CarbonTable WHERE STARTTIME
BEFORE '2017-06-01 12:05:06';
+ ```
+
+***
+
+# UPDATE CARBON TABLE
+This command updates the carbon table based on the column expression and
optional filter conditions.
+
+The client node where the UPDATE command is executed should be part of the
cluster.
+### Syntax
+Syntax1:
+ ```ruby
+ UPDATE <CARBON TABLE>
+ SET (column_name1, column_name2, ... column_name n) =
(column1_expression , column2_expression , column3_expression . .. column
n_expression )
+ [ WHERE { <filter_condition> } ];
+ ```
+Syntax2:
+ ```ruby
+ UPDATE <CARBON TABLE>
+ SET (column_name1, column_name2,) = (select sourceColumn1,
sourceColumn2 from sourceTable [ WHERE { <filter_condition> } ] )
+ [ WHERE { <filter_condition> } ];
+ ```
+
+### Parameter Description
+
+| Parameter | Description |
+| ------------- | -----|
+| CARBON TABLE | The name of the Carbon table in which you want to perform
the update operation. |
+| column_name | The destination columns to be updated. |
+| sourceColumn | The source table column values to be updated in
destination table. |
+| sourceTable | The table from which the records are updated into
destination Carbon table. |
+
+### Usage Guidelines
+Following are the conditions to use UPDATE:
+- The update command fails if multiple input rows in source table are
matched with single row in destination table.
+- If the source table generates empty records, the update operation will
complete without updating the table.
+- If a source table row does not correspond to any of the existing rows in
a destination table, the update operation will complete without updating the
table.
+- In sub-query, if the source table and the target table are same, then
the update operation fails.
+- If the sub-query used in UPDATE statement contains aggregate method or
group by query, then the UPDATE operation fails.
+ For example, update t_carbn01 a set (a.item_type_code, a.profit) = (
select b.item_type_cd, sum(b.profit) from t_carbn01b b where item_type_cd =2
group by item_type_code);
+ Here, aggregate function sum(b.profit) and group by clause are used in
the sub-query, hence the UPDATE operation fails.
+
+**Example1:**
+ ```ruby
+ update carbonTable1 d set (d.column3,d.column5 ) = (select s.c33 ,s.c55
from sourceTable1 s where d.column1 = s.c11) where d.column1 = 'china' exists(
select * from table3 o where o.c2 > 1);
--- End diff --
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