Hello,
Roy Lyseng a écrit, Le 21.09.2010 13:41:
> #At file:///home/rl136806/mysql/repo/mysql-review/ based on
> revid:roy.lyseng@stripped
>
> 3245 Roy Lyseng 2010-09-21
> Refactoring: Make members positions and best_positions of class JOIN
> dynamically allocated instead of fixed-size arrays.
> This saves approx. 20 kbyte memory during optimization and execution
> for normal-sized join operations.
Good catch!
> === modified file 'sql/sql_select.cc'
> --- a/sql/sql_select.cc 2010-09-20 14:06:02 +0000
> +++ b/sql/sql_select.cc 2010-09-21 11:36:51 +0000
> @@ -4490,6 +4490,14 @@ make_join_statistics(JOIN *join, TABLE_L
> if (!stat || !stat_ref || !table_vector)
> DBUG_RETURN(1); // Eom /* purecov: inspected */
>
> + if (!(join->positions=
> + (POSITION *)join->thd->alloc(sizeof(POSITION)*(table_count+1))))
> + DBUG_RETURN(TRUE);
> +
> + if (!(join->best_positions=
> + (POSITION *)join->thd->alloc(sizeof(POSITION)*(table_count+1))))
> + DBUG_RETURN(TRUE);
> +
this, or like is done in the previous lines for stat/stat_ref/table_vector:
just do a bunch of
x= join->thd->alloc()
and one final test
if (!x || !y || !z || !t || etc)
DBUG_RETURN(TRUE);
Ok to push.
As this patch is touching memory allocation and using MEM_ROOT (via
thd->alloc()), I suggest running all optimizer tests with --ps-protocol
--valgrind to see whether there's a problem before pushing.
Thanks.
