Description:
When sort_buffer_size is set to a different value, group_concat returns different results.
How to repeat:
For details about table_test.sql, see the attachment.
source table_test.sql
set sort_buffer_size = 262144;
select datetime_col, float_col, group_concat(id_col) from table_test group by 1,2 order by 1,2,3 limit 1;
set sort_buffer_size = 10737418240;
select datetime_col, float_col, group_concat(id_col) from table_test group by 1,2 order by 1,2,3 limit 1;
mysql> set sort_buffer_size = 262144;
Query OK, 0 rows affected (0.00 sec)
mysql> select datetime_col, float_col, group_concat(id_col) from table_test group by 1,2 order by 1,2,3 limit 1;
+----------------------------+-------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| datetime_col | float_col | group_concat(id_col) |
+----------------------------+-------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| 1000-01-01 00:00:00.000000 | -3.40282e38 | 88,88,88,88,88,89,89,89,89,89,90,90,90,90,90,91,91,91,91,91,92,92,92,92,92,93,93,93,93,93,94,94,94,94,94,95,95,95,95,95,96,96,96,96,96,97,97,97,97,97,98,98,98,98,98,99,99,99,99,99,100,100,100,100,100,101,101,101,101,101,102,102,102,102,102,103,103,103,103,103,104,104,104,104,104,105,105,105,105,105,106,106,106,106,106,107,107,107,107,107,108,108,108,108,108,109,109,109,109,109,110,110,110,110,110,111,111,111,111,111,112,112,112,112,112,113,113,113,113,113,1,2,3,4,5,5,5,5,5,5,1,1,1,1,1,10,10,10,10,10,20,20,20,20,20,30,30,30,30,30,40,40,40,40,40,50,50,50,50,50,60,60,60,60,60,70,70,70,70,70,80,80,80,80,80,90,90,90,90,90,100,100,100,100,100,1,1,1,1,1,2,2,2,2,2,3,3,3,3,3,4,4,4,4,4,5,5,5,5,5,6,6,6,6,6,7,7,7,7,7,8,8,8,8,8,9,9,9,9,9,10,10,10,10,10,11,11,11,11,11,12,12,12,12,12,13,13,13,13,13,14,14,14,14,14,15,15,15,15,15,16,16,16,16,16,17,17,17,17,17,18,18,18,18,18,19,19,19,19,19,20,20,20,20,20,21,21,21,21,21,22,22,22,22,22,23,23,23,23,23,24,24,24,24,24,25,25,25,25,25,26,26,26,26,26,27,27,27,27,27,28,28,28,28,28,29,2 |
+----------------------------+-------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
1 row in set, 21 warnings (0.02 sec)
mysql> set sort_buffer_size = 10737418240;
Query OK, 0 rows affected (0.00 sec)
mysql> select datetime_col, float_col, group_concat(id_col) from table_test group by 1,2 order by 1,2,3 limit 1;
+----------------------------+-------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| datetime_col | float_col | group_concat(id_col) |
+----------------------------+-------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| 1000-01-01 00:00:00.000000 | -3.40282e38 | 1,2,3,4,5,5,5,5,5,5,1,1,1,1,1,10,10,10,10,10,20,20,20,20,20,30,30,30,30,30,40,40,40,40,40,50,50,50,50,50,60,60,60,60,60,70,70,70,70,70,80,80,80,80,80,90,90,90,90,90,100,100,100,100,100,1,1,1,1,1,2,2,2,2,2,3,3,3,3,3,4,4,4,4,4,5,5,5,5,5,6,6,6,6,6,7,7,7,7,7,8,8,8,8,8,9,9,9,9,9,10,10,10,10,10,11,11,11,11,11,12,12,12,12,12,13,13,13,13,13,14,14,14,14,14,15,15,15,15,15,16,16,16,16,16,17,17,17,17,17,18,18,18,18,18,19,19,19,19,19,20,20,20,20,20,21,21,21,21,21,22,22,22,22,22,23,23,23,23,23,24,24,24,24,24,25,25,25,25,25,26,26,26,26,26,27,27,27,27,27,28,28,28,28,28,29,29,29,29,29,30,30,30,30,30,31,31,31,31,31,32,32,32,32,32,33,33,33,33,33,34,34,34,34,34,35,35,35,35,35,36,36,36,36,36,37,37,37,37,37,38,38,38,38,38,39,39,39,39,39,40,40,40,40,40,41,41,41,41,41,42,42,42,42,42,43,43,43,43,43,44,44,44,44,44,45,45,45,45,45,46,46,46,46,46,47,47,47,47,47,48,48,48,48,48,49,49,49,49,49,50,50,50,50,50,51,51,51,51,51,52,52,52,52,52,53,53,53,53,53,54,54,54,54,54,55,55,55,55,55,56,56,56,56,56,57,57,57,57,57,58,58,58,58,58,59,59,59,59,59 |
+----------------------------+-------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
1 row in set, 21 warnings (0.02 sec)
