| Bug #16857 | Altering BINARY(x) column uses incorrect padding | ||
|---|---|---|---|
| Submitted: | 27 Jan 2006 22:07 | Modified: | 9 Apr 2006 4:48 |
| Reporter: | Kolbe Kegel | Email Updates: | |
| Status: | Closed | Impact on me: | |
| Category: | MySQL Server | Severity: | S1 (Critical) |
| Version: | 5.0.19 | OS: | Linux (Linux) |
| Assigned to: | Chad MILLER | CPU Architecture: | Any |
[27 Jan 2006 22:46]
Jorge del Conde
Verified w/fresh pull of 5.0 under FC4
[2 Mar 2006 19:21]
Chad MILLER
Leads to data corruption.
[3 Mar 2006 1:00]
Bugs System
A patch for this bug has been committed. After review, it may be pushed to the relevant source trees for release in the next version. You can access the patch from: http://lists.mysql.com/commits/3410
[3 Mar 2006 1:49]
Bugs System
A patch for this bug has been committed. After review, it may be pushed to the relevant source trees for release in the next version. You can access the patch from: http://lists.mysql.com/commits/3411
[3 Mar 2006 2:10]
Chad MILLER
BINARY columns should not be treated as other *CHAR columns when it comes to expanding columns. Changeset 1.2096, in v5.0.19 changes the behavior to fill new positions in expanded BINARY columns with 0x00 bytes instead of ASCII spaces.
[4 Mar 2006 0:58]
Paul DuBois
Noted in 5.0.19 changelog. Using <literal>ALTER TABLE</literal> to increase the length of a <literal>BINARY(<replaceable>M</replaceable>)</literal> column caused column values to be padded with spaces rather than <literal>0x00</literal> bytes. (Bug #16857)
[9 Apr 2006 4:48]
Paul DuBois
Noted in 5.1.8 changelog, too.
Description: Given a BINARY(X) column, using ALTER TABLE to change the column to BINARY(Y) where Y > X, the end of the column is padded with 0x20 instead of 0x00. How to repeat: create table table1 (col1 binary(4)); insert into table1 values ('a'),('a '); select hex(col1) from table1; alter table table1 modify col1 binary(10); select hex(col1) from table1; insert into table1 values ('b'),('b '); select hex(col1) from table1; mysql 5.0.19-debug (root) [test]> create table table1 (col1 binary(4)); Query OK, 0 rows affected (0.00 sec) mysql 5.0.19-debug (root) [test]> insert into table1 values ('a'),('a '); Query OK, 2 rows affected (0.00 sec) Records: 2 Duplicates: 0 Warnings: 0 mysql 5.0.19-debug (root) [test]> select hex(col1) from table1; +-----------+ | hex(col1) | +-----------+ | 61000000 | | 61200000 | +-----------+ 2 rows in set (0.00 sec) mysql 5.0.19-debug (root) [test]> alter table table1 modify col1 binary(10); Query OK, 2 rows affected (0.01 sec) Records: 2 Duplicates: 0 Warnings: 0 mysql 5.0.19-debug (root) [test]> select hex(col1) from table1; +----------------------+ | hex(col1) | +----------------------+ | 61000000202020202020 | | 61200000202020202020 | +----------------------+ 2 rows in set (0.00 sec) mysql 5.0.19-debug (root) [test]> insert into table1 values ('b'),('b '); Query OK, 2 rows affected (0.00 sec) Records: 2 Duplicates: 0 Warnings: 0 mysql 5.0.19-debug (root) [test]> select hex(col1) from table1; +----------------------+ | hex(col1) | +----------------------+ | 61000000202020202020 | | 61200000202020202020 | | 62000000000000000000 | | 62200000000000000000 | +----------------------+ 4 rows in set (0.00 sec) Suggested fix: The server should use 0x00 instead of 0x20 to pad BINARY columns when they are altered to a larger size.