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From:Martin Hansson Date:December 13 2010 12:26pm
Subject:Re: bzr commit into mysql-5.1-bugteam branch (sergey.glukhov:3515)
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Sergey Glukhov skrev 2010-12-10 13.06:
> #At file:///home/gluh/MySQL/mysql-5.1-bugteam/ based on
> revid:bjorn.munch@stripped
>   3515 Sergey Glukhov	2010-12-10
>        Bug#48916 Server incorrectly processing HAVING clauses with an ORDER BY
> clause
>        Before sorting HAVING condition is splitted into two parts,
>        first past is a table related condition and the rest of is
>        HAVING part. Extraction of HAVING part does not take into account
>        the fact that some of conditions might be non-const but
>        have 'used_tables' == 0 (undependent subqueries)
>        and because of that these conditions are cut off by
>        make_cond_for_table() function.
>        The fix is to use (table_map) 0 instead of used_tables in
>        third argument for make_cond_for_table() function.
>        It allows to extract elements which belong to sorted
>        table and in addition elements which are undependend
>        subqueries.
You might want to run a spell-checker on the comment. Misspelled change 
set comments take longer to read.

I don't understand your fix. Ok, I understand that the IN condition is 
non-constant but still doesn't refer to any tables. But why is there any 
difference between sending a constant 0 and a variable which is 0? 
Actually, I ran some test on my machine and I get used_tables == 1. Have 
I missed something?

I ran the test with your fix and as you're saying, the condition 
<in_optimizer>((3,2),<exists>(select 4,2 having (((<cache>(3) = 4) or 
isnull(4)) and ((<cache>(2) = 2) or isnull(2)) and <is_not_null_test>(4) 
and <is_not_null_test>(2)))) goes missing without your fix, but why?

Best Regards

bzr commit into mysql-5.1-bugteam branch (sergey.glukhov:3515) Bug#48916Sergey Glukhov10 Dec
  • Re: bzr commit into mysql-5.1-bugteam branch (sergey.glukhov:3515)Bug#48916Martin Hansson13 Dec
  • Re: bzr commit into mysql-5.1-bugteam branch (sergey.glukhov:3515)Bug#48916Martin Hansson29 Dec
Re: bzr commit into mysql-5.1-bugteam branch (sergey.glukhov:3515)Bug#48916Martin Hansson29 Dec