maria-developers team mailing list archive

[Sergey Petrunya <psergey@xxxxxxxxxxxx>]

Hello Igor,

On Thu, Nov 18, 2010 at 02:17:13PM -0800, Igor Babaev wrote:
> Sergey,
> 
> Please review this patch ASAP as this bug blocks Philip with testing.
> If you have any questions contact me by skype.
> 

Ok to push after the comment below is addressed.

> -------- Original Message --------
> Subject: 	[Commits] Rev 2859: Fixed LP #bug 660963. in
> file:///home/igor/maria/maria-5.3-mwl128-bug660963/
> Date: 	Thu, 18 Nov 2010 14:13:58 -0800 (PST)
> From: 	Igor Babaev <igor@xxxxxxxxxxxx>
> Reply-To: 	maria-developers@xxxxxxxxxxxxxxxxxxx
> To: 	<commits@xxxxxxxxxxx>
> 
> 
> 
> At file:///home/igor/maria/maria-5.3-mwl128-bug660963/
> 
> ------------------------------------------------------------
> revno: 2859
> revision-id: igor@xxxxxxxxxxxx-20101118221357-zg55d3erru07ugzy
> parent: igor@xxxxxxxxxxxx-20101116050732-hpbqelsf8nvae4xt
> committer: Igor Babaev <igor@xxxxxxxxxxxx>
> branch nick: maria-5.3-mwl128-bug660963
> timestamp: Thu 2010-11-18 14:13:57 -0800
> message:
>   Fixed LP #bug 660963.
>   The condition that was supposed to check whether a join table
>   is an inner table of a nested outer join or semi-join was not
>   quite correct in the code of the function check_join_cache_usage.
>   That's why some queries with nested outer joins triggered 
>   an assertion failure.
>   Encapsulated this condition in the new method called
>   JOIN_TAB::is_nested_inner and provided a proper code for it.
>   
>   Also corrected a bug in the code of check_join_cache_usage()
>   that caused a downgrade of not first join buffers of the
>   level 5 and 7 to level 4 and 6 correspondingly.
> 
...
> === modified file 'sql/sql_select.cc'
> --- a/sql/sql_select.cc	2010-11-16 05:07:32 +0000
> +++ b/sql/sql_select.cc	2010-11-18 22:13:57 +0000
> @@ -7635,8 +7635,7 @@
>    if (cache_level == 0 || i == join->const_tables || !prev_tab)
>      return 0;
>  
> -  if (force_unlinked_cache && 
> -      (cache_level & JOIN_CACHE_INCREMENTAL_BIT))
> +  if (force_unlinked_cache && (cache_level%2 == 0))
>      cache_level--;
>  
>    if (options & SELECT_NO_JOIN_CACHE)
> @@ -7658,13 +7657,14 @@
>    /*
>      Non-linked join buffers can't guarantee one match
>    */
> -  if ((force_unlinked_cache || cache_level == 1) &&  
> -      ((tab->is_inner_table_of_semi_join_with_first_match() &&
> -        !tab->is_single_inner_of_semi_join_with_first_match()) ||
> -       (tab->is_inner_table_of_outer_join() &&
> -        !tab->is_single_inner_of_outer_join())))
> -   goto no_join_cache;
> -
> +  if (tab->is_nested_inner())
> +  {
> +    if (force_unlinked_cache || cache_level == 1)
> +      goto no_join_cache;
> +    if (cache_level & 1)
> +      cache_level--;
> +  }
> +    
>    /*
>      Don't use join buffering if we're dictated not to by no_jbuf_after (this
>      ...)
> @@ -7757,9 +7757,6 @@
>  	(cache_level <= 6 || no_hashed_cache))
>        goto no_join_cache;
>  
> -    if (prev_tab->cache && cache_level==7)
> -      cache_level= 6;
> -    
>      if ((rows != HA_POS_ERROR) && !(flags & HA_MRR_USE_DEFAULT_IMPL))
>      {
>        if (cache_level <= 6 || no_hashed_cache)
> 
> === modified file 'sql/sql_select.h'
> --- a/sql/sql_select.h	2010-11-13 14:13:34 +0000
> +++ b/sql/sql_select.h	2010-11-18 22:13:57 +0000
> @@ -359,6 +359,14 @@
>      return (first_inner && first_inner->last_inner == this) ||
>             last_sj_inner_tab == this;
>    }
> +  bool is_nested_inner()
Please add a comment clarifying what this function checks.

> +  {
> +    if (first_inner && (first_inner != last_inner || first_upper))
> +      return TRUE;
> +    if (first_sj_inner_tab && first_sj_inner_tab != last_sj_inner_tab)
> +      return TRUE;
> +    return FALSE;
> +  }
>    struct st_join_table *get_first_inner_table()
>    {
>      if (first_inner)
> 

BR
 Sergey
-- 
Sergey Petrunia, Software Developer
Monty Program AB, http://askmonty.org
Blog: http://s.petrunia.net/blog