[jira] [Created] (CARBONDATA-2550) [MV] Limit is ignored when data fetched from MV, Query rewrite is Wrong

[Akash R Nilugal (Jira)]

Babulal created CARBONDATA-2550:
-----------------------------------

             Summary: [MV] Limit is ignored when data fetched from MV, Query rewrite is Wrong
                 Key: CARBONDATA-2550
                 URL: https://issues.apache.org/jira/browse/CARBONDATA-2550
             Project: CarbonData
          Issue Type: Bug
            Reporter: Babulal


0: jdbc:hive2://10.18.222.231:23040> create table mvtable1(name string,age int,salary int) stored by 'carbondata';
+---------+--+
| Result |
+---------+--+
+---------+--+
No rows selected (0.279 seconds)
0: jdbc:hive2://10.18.222.231:23040> insert into mvtable1 select 'n1',12,12;
+---------+--+
| Result |
+---------+--+
+---------+--+
No rows selected (11.973 seconds)
0: jdbc:hive2://10.18.222.231:23040> insert into mvtable1 select 'n1',12,12;
+---------+--+
| Result |
+---------+--+
+---------+--+
No rows selected (9.92 seconds)
0: jdbc:hive2://10.18.222.231:23040> insert into mvtable1 select 'n3',12,12;
+---------+--+
| Result |
+---------+--+
+---------+--+
No rows selected (9.883 seconds)
0: jdbc:hive2://10.18.222.231:23040> insert into mvtable1 select 'n4',12,12;
+---------+--+
| Result |
+---------+--+
+---------+--+
No rows selected (10.488 seconds)
0: jdbc:hive2://10.18.222.231:23040> select name,sum(salary) from mvtable1 group by name;
+-------+--------------+--+
| name | sum(salary) |
+-------+--------------+--+
| n3 | 12 |
| n1 | 24 |
| n4 | 12 |
+-------+--------------+–+

0: jdbc:hive2://10.18.222.231:23040> select name,sum(salary) from mvtable1 group by name limit 2;
+-------+--------------+--+
| name | sum(salary) |
+-------+--------------+--+
| n3 | 12 |
| n1 | 24 |
+-------+--------------+--+
2 rows selected (4.175 seconds)
0: jdbc:hive2://10.18.222.231:23040> create datamap map1 using 'mv' as select name,sum(salary) from mvtable1 group by name;
+---------+--+
| Result |
+---------+--+
+---------+--+
No rows selected (0.396 seconds)
0: jdbc:hive2://10.18.222.231:23040> rebuild datamap map1;
+---------+--+
| Result |
+---------+--+
+---------+--+
No rows selected (13.246 seconds)

 

*0: jdbc:hive2://10.18.222.231:23040> select name,sum(salary) from mvtable1 group by name limit 2;*
+----------------+-------------+--+
| mvtable1_name | sum_salary |
+----------------+-------------+--+
| n3 | 12 |
| n1 | 24 |
| n4 | 12 |
+----------------+-------------+--+
3 rows selected (2.453 seconds)
*0: jdbc:hive2://10.18.222.231:23040> select name,sum(salary) from mvtable1 group by name limit 1;*
+----------------+-------------+--+
| mvtable1_name | sum_salary |
+----------------+-------------+--+
| n3 | 12 |
| n1 | 24 |
| n4 | 12 |
+----------------+-------------+--+
3 rows selected (0.347 seconds)
0: jdbc:hive2://10.18.222.231:23040>

 

 

Even limit is given MV returns all the records from MV table.

Cause:- 

When Rewriting MV query ,limit is ignored,

0: jdbc:hive2://10.18.222.231:23040> explain select name,sum(salary) from mvtable1 *group by name limit 2;*

| plan |

| == CarbonData Profiler ==
Table Scan on map1_table
 - total blocklets: 2
 - filter: none
 - pruned by Main DataMap
 - skipped blocklets: 0
 |
| == Physical Plan ==
*BatchedScan CarbonDatasourceHadoopRelation [ Database name :default, Table name :map1_table, Schema :Some(StructType(StructField(mvtable1_name,StringType,true), StructField(sum_salary,LongType,true))) ] default.map1_table[mvtable1_name#4438,sum_salary#4614L] |
+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+--+
2 rows selected (0.36

 

 



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