Elena Stepanova added a comment - 2015-11-09 18:01 - edited bala.linux , are you using MyISAM engine for the table? For now I'll assume you are. --source include/have_partition.inc   create table t1 (i int) engine=MyISAM partition by hash(i) partitions 2; alter table t1 comment 'test', algorithm=inplace; drop table t1; MariaDB [test]> alter table t1 comment 'test', algorithm=inplace; ERROR 1845 (0A000): ALGORITHM=INPLACE is not supported for this operation. Try ALGORITHM=COPY. Works okay with InnoDB and without partitioning. Reproducible on MySQL 5.6.10, but apparently it was fixed in MySQL 5.6.11 – the release notes have this: Partitioning: ALGORITHM = INPLACE, which was disallowed in MySQL 5.6.10 for DDL statements operating on partitioned tables, can once again be used with such statements. (Bug #16216513) References: See also Bug #14760210. Maybe we got the InnoDB part of the fix with regular InnoDB merges, but MyISAM still has the problem.

Bala added a comment - 2015-11-11 10:59 Yes. We are using MyISAM with partitioning.

Bala added a comment - 2016-04-04 11:33 - edited Team, Looks like this hasn't got fixed yet. I tried the test case from comment #1 and it failed to work. Please check. mysql> show variables like '%version%'; +-------------------------+---------------------------------+ | Variable_name | Value | +-------------------------+---------------------------------+ | innodb_version | 5.6.28-76.1 | | protocol_version | 10 | | slave_type_conversions | | | version | 10.0.24-MariaDB-1~trusty | | version_comment | mariadb.org binary distribution | | version_compile_machine | x86_64 | | version_compile_os | debian-linux-gnu | | version_malloc_library | bundled jemalloc | +-------------------------+---------------------------------+ 8 rows in set (0.00 sec)   mysql> create table t1 (i int) engine=MyISAM partition by hash(i) partitions 2; Query OK, 0 rows affected (0.00 sec)   mysql> alter table t1 comment 'test', algorithm=inplace; ERROR 1845 (0A000): ALGORITHM=INPLACE is not supported for this operation. Try ALGORITHM=COPY. mysql> Thanks. -Bala

Elena Stepanova added a comment - 2016-04-04 12:06 serg , see above ^ I see the commit related to this bug report, but maybe you only pushed a part of the patch? I don't see the test case for MyISAM/partition there.

Sergei Golubchik added a comment - 2016-04-04 14:41 bala.linux , you're right. This was fixed only for not partitioned table. I'm sorry for this. I've now created a new MDEV-9868 specifically for partitioned tables, it will be fixed in the next release.

Bala added a comment - 2016-04-05 05:23 - edited Thanks. Also, would it be possible to do something similar for altering "column" comments ? It does the full copy too. I created MDEV-9168 but never got any attention. Please let me know. -Bala

Sergei Golubchik added a comment - 2016-04-06 14:58 MDEV-9168 is a Task listing two distinct issues: the awkward syntax and a full table copy. If you'd like I can convert it to a Bug about full table copy when altering column comments. Alternatively, you can create a new bug report for the latter and keep the task to deal with the awkward syntax.

Bala added a comment - 2016-04-06 16:42 - edited Yes. Please convert it to a bug to track "full table copy when altering column comments". I created a new bug for the awkward syntax ( MDEV-9878 ). Thanks. -Bala