chenerlu created CARBONDATA-1438:
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             Summary: Unify the sort column and sort scope in create table 
command
                 Key: CARBONDATA-1438
                 URL: https://issues.apache.org/jira/browse/CARBONDATA-1438
             Project: CarbonData
          Issue Type: Bug
            Reporter: chenerlu



1       Requirement
Currently, Users can specify sort column in table properties when create table. 
And when load data, users can also specify sort scope in load options.
In order to improve the ease of use for users, it will be better to specify the 
sort related parameters all in create table command.
Once sort scope is specified in create table command, it will be used in load 
data even users have specified in load options.

2       Detailed design
2.1     Task-01
Requirement: Create table can support specify sort scope
Implement: Take use of table properties (Map<String, String>), will specify 
sort scope in table properties by key/value pair, then existing interface will 
be called to write this key/value pair into metastore.
Will support Global Sort,Local Sort and No Sort,it can be specified in sql 
command:

CREATE TABLE tableWithGlobalSort (
shortField SHORT,
intField INT,
bigintField LONG,
doubleField DOUBLE,
stringField STRING,
timestampField TIMESTAMP,
decimalField DECIMAL(18,2),
dateField DATE,
charField CHAR(5)
)
STORED BY 'carbondata'
TBLPROPERTIES('SORT_COLUMNS'='stringField', 'SORT_SCOPE'='GLOBAL_SORT')
 
Tips:If the sort scope is global Sort, users should specify 
GLOBAL_SORT_PARTITIONS. If users do not specify it, it will use the number of 
map task. GLOBAL_SORT_PARTITIONS should be Integer type, the range is 
[1,Integer.MaxValue],it is only used when the sort scope is global sort. 

Global Sort     Use orderby operator in spark, data is ordered in segment level.
Local Sort      Node ordered, carbondata file is ordered if it is written by 
one task. 
No Sort No sort

Tips:key and value is case-insensitive.
2.2     Task-02
Requirement:
Load data in will support local sort, no sort, global sort 
Ignore the sort scope specified in load data and use the parameter which 
specified in create table.

Currently, user can specify the sort scope and global sort partitions in load 
options, After modification, it will ignore the sort scope which specified in 
load options and will get sort scope from table properties.

Current logic: sort scope is from load options
Number          Prerequisite    Sort scope
1       isSortTable is true && Sort Scope is Global Sort        Global 
Sort(first check)
2       isSortTable is false    No Sort
3       isSortTable is true     Local Sort
Tips: isSortTable is true means this table contains sort column or it contains 
dimensions (except complex type), like string type.

For example:
Create table xxx1 (col1 string col2 int) stored by ‘carbondata’ --- sort table
Create table xx1 (col1 int, col2 int) stored by ‘carbondata’ --- not sort table
Create table xx (col1 int, col2 string) stored by ‘carbondata’ tblproperties 
(‘sort_column’=’col1’)  –- sort table

New logic:sort scope is from create table
Number  Prerequisite    Code branch
1       isSortTable = true && Sort Scope is Global Sort Global Sort(first check)
2       isSortTable= false || Sort Scope is No Sort     No Sort
3       isSortTable is true && Sort Scope is Local Sort Local Sort
4       isSortTable is true,without specify Sort Scope  Local Sort, (Keep 
current logic) 

3       Acceptance standard
Number  Acceptance standard
1       Use can specify sort scope(global, local, no sort) when create carbon 
table in sql type
2       Load data will ignore the sort scope specified in load options and will 
use the parameter which specify in create table command. If user still specify 
the sort scope in load options, will give warning and inform user that he will 
use the sort scope which specified in create table.

4       Feature restrictions
NA
5       Dependencies
NA
6       Technical risk
NA




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