From: Ingo Strüwing
Date: November 6 2008 3:46pm
Subject: Re: bzr commit into mysql-5.1 branch (kgeorge:2690) Bug#37936
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Hi Joro,

Georgi Kodinov, 06.11.2008 15:45:
...
> Now assume that read_set is the same as write_set, i.e.
> read_set->bitmap is 1
> write_set->bitmap is 1
> all_set->bitmap is 3
> 
> save_read_set_bitmap= read_set->bitmap; read_set->bitmap= all_set->bitmap;
> save_write_set_bitmap= write_set->bitmap; write_set->bitmap=
> all_set->bitmap;
> 
> as a result we have :
> save_read_set_bitmap is 1
> read_set->bitmap is 3
> save_write_set_bitmap is 3 (because read_set->bitmap was already set
> when saving the write_set)

Ok. After some thinking, I found another level of indirection below
read_set and write_set. I am completely confused. I should not do this
review.

Though I do now seem to understand that both bitmaps still referred to
all_set after restore, and thus all later changes to them corrupted
all_set, I don't dare to approve the patch. I was as sure, that it was
wrong, before our conversation. Sorry. :-(

Regards
Ingo
-- 
Ingo Strüwing, Database Group
Sun Microsystems GmbH, Sonnenallee 1, D-85551 Kirchheim-Heimstetten
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