Re: bzr commit into mysql-5.0-bugteam branch (gshchepa:2711) Bug#40021

[Oleksandr \"Sanja\" Byelkin]

Hi!

Gleb Shchepa пишет:
> #At file:///work/bzr/5.0-bugteam-40021/
> 
>  2711 Gleb Shchepa	2008-11-10
>       Bug #40021: Renaming view fails, archived .frm for view is
>                   missing after downgrade
>       
>       Obsolete arc/ directory and view .frm file backup support
>       has been removed by the patch for bug 17823. However, that
>       bugfix caused a problem with "live downgrades" of the
>       server: if we rename some view 4 times under 5.1.29/5.0.72
>       and then try to rename it under 5.1.28/5.0.70 on the same
>       database, the server fails with a error:
>       
>         query 'RENAME TABLE ... TO ...' failed: 6: Error on
>         delete of '....frm-0001' (Errcode: 2)
>       
>       Also .frm file of that view may be lost (renamed to .frm~).
>       
>       The server failed because it tried to rename latest 3
>       backup .frm files renaming the view: the server used an
>       integer value of the "revision" field of .frm file to
>       extract those file names. After the fix for bug 17823 those
>       files were not created/maintained any more, however the
>       "revision" field was incremented as usual. So, the server
>       failed renaming non existent files.
>       
>       This fix solves the problem by removing the support for
>       "revision" .frm file field:
>       1. New server silently ignores existent "revision" fields
>          in old .frm files and never write it down;
>       2. Old server assumes, that missing "revision" field in new
>          .frm files means default value of 0.
>       3. Accordingly to the fix for bug 17823 the new server
>          drops arc/ directory on alter/rename view, so after
>          "live downgrade" old server begins maintenance of the
>          arc/ directory from scratch without conflicts with .frm
>          files.
>


OK to push

[skip]

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