Details
- 
    Bug 
- 
    Status: Closed (View Workflow)
- 
    Major 
- 
    Resolution: Fixed
- 
    5.5.1, 5.6.1, 6.1.1
- 
    None
- 
        2021-5, 2021-6
Description
| DROP TABLE IF EXISTS t1; | 
| CREATE TABLE t1 (a DECIMAL(17,1)) ENGINE=ColumnStore; | 
| INSERT INTO t1 VALUES (-8999999999999999.9); | 
| SELECT GROUP_CONCAT(a) FROM t1; | 
| +---------------------+ | 
| | GROUP_CONCAT(a)     | | 
| +---------------------+ | 
| | -9000000000000000.0 | | 
| +---------------------+
 | 
Looks wrong. The expected result is '-8999999999999999.9'.
This happens because the underlying printing code in  GroupConcator::outputRow() uses double representation.
It should be fixed to print DECIMAL natively.