maria-developers team mailing list archive

[Nirbhay Choubey <nirbhay@xxxxxxxxxxx>]

Hi Monty,

On Tue, Jun 21, 2016 at 9:30 AM, Michael Widenius <monty@xxxxxxxxxxx> wrote:

>
> Hi!
>
> >>>>> "Nirbhay" == Nirbhay Choubey <nirbhay@xxxxxxxxxxx> writes:
>
> <cut>
>
> Nirbhay> ALTER TABLE implementation takes a shortcut for operations not
> affecting
> Nirbhay> .frm files,
> Nirbhay> which includes simple RENAMEs. But this is skipped for temp
> tables and thus
> Nirbhay> copying
> Nirbhay> always takes place for temp tables.
>
> Nirbhay> The following commit (from 2002) added this exception for temp
> tables:
> Nirbhay>
> https://github.com/MariaDB/server/commit/a7798dfd0a6472bf65fffc2ade543605e177ff9c
>
> The above old patch is not really working for the current code.
>
> Nirbhay> I have created a patch to also include temp tables to this
> shortcut :
> Nirbhay> https://gist.github.com/nirbhayc/442a0c269ce48b283543cac434aaf44e
>
> This solves the problem of doing a simple rename, but not for things
> like:
>
> alter table t1 add column c int, rename to t2;
>
> Which will still produce crashes.
>
> When it comes to last_version, is still vote for that we should be using
> THD::rename_temporary_table when renaming temporary tables instead of
> doing any handler calls.
>

Right.


>
> Maybe we could move THD::rename_temporary_tables to ha_rename_table to
> get all temporary tables handled in one place ?
>

handler::ha_rename_table() is currently being used only for non-temporary
tables at
places which do not support temporary tables like partitions, DDL logs,
RENAME
TABLE, etc. So, moving rename_temporary_table to ha_rename_table seem
overkill
and possibly inappropriate.

Here's the latest version of patch :
http://lists.askmonty.org/pipermail/commits/2016-June/009477.html

Best,
Nirbhay


> Regards,
> Monty
>