database/mariadb
1
0
Fork 0
mirror of https://github.com/MariaDB/server.git synced 2025-08-08 11:22:35 +03:00
Code Activity

MDEV-27277 Add a warning when max_sort_length is reached

Browse Source 
During a query execution some sorting and grouping operations
on strings may be involved. System variable max_sort_length defines
the maximum number of bytes to use when comparing strings during
sorting/grouping. Thus, the comparable parts of strings may be less
than their actual size, so the results of the query may be not
sorted/grouped properly.
To indicate that some comparisons were done on a truncated lengths,
a new warning has been introduced with this commit.
This commit is contained in:
Oleg Smirnov
2023-09-04 13:15:06 +07:00
parent 0d17c540a5
commit fd87e01f38
20 changed files with 432 additions and 28 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
mysql-test/suite/versioning/r/update.result
View File

@@ -257,12 +257,16 @@ select x, left(y, 4), length(y), check_row(row_start, row_end) from t1 for syste
x left(y, 4) length(y) check_row(row_start, row_end)
1 LONG 8192 HISTORICAL ROW
2 LONG 8192 CURRENT ROW
Warnings:
Warning 4202 2 values were longer than max_sort_length. Sorting used only the first 1024 bytes
update t1 set y= 'SHORT';
select x, left(y, 4), length(y), check_row(row_start, row_end) from t1 for system_time all order by x, y;
x left(y, 4) length(y) check_row(row_start, row_end)
1 LONG 8192 HISTORICAL ROW
2 LONG 8192 HISTORICAL ROW
2 SHOR 5 CURRENT ROW
Warnings:
Warning 4202 2 values were longer than max_sort_length. Sorting used only the first 1024 bytes
drop tables t1;
### Issue tempesta-tech/mariadb#365, bug 7 (duplicate of historical row)
create or replace table t1 (a int primary key, b int)