From: Roy Lyseng
Date: June 21 2011 9:11am
Subject: Re: bzr commit into mysql-trunk branch (roy.lyseng:3385) Bug#12603200
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Hi Øystein,

thank you for reviewing.

On 17.06.11 10.54, Øystein Grøvlen wrote:
> Approved with the following suggestions:
>
> - Test case could be simplified (e.g., remove columns that are not
> referred by query)

I tried to delete the col_int_key column from both tables, but the original 
query did not fail after that.
>
> - Maybe you should add EXPLAIN for this query to make sure it is
> noticed if plan is changed and query no longer tests what it is
> supposed to.

Yes, will do.
>
> - Could add to the comment something about deleting the quick object,
> or maybe that is too evident.

Will do.
>
> --
> Øystein
>
>
> On 15/06/2011 15:57, Roy Lyseng wrote:
>  > #At file:///home/rl136806/mysql/repo/mysql-work0/ based on
> revid:jorgen.loland@stripped
>  >
>  > 3385 Roy Lyseng 2011-06-15
>  > Bug#12603200: Assert in QUICK_INDEX_MERGE_SELECT::need_sorted_output
>  >
>  > The problematic query is semi-join transformed and a LooseScan
>  > strategy is selected. setup_semijoin_dups_elimination() inspects
>  > the provided quick select object and attempts to set it to require
>  > ordering of output rows. However, the quick select object was not
>  > selected in the first place (see
>  > Loose_scan_opt::check_ref_access_part1()), hence there is a missing
>  > check that the index covered by the quick select matches the index
>  > selected for the loose scan access.
>  >
>  > Fixed by adding this check, and also deleting the quick select object
>  > if it was not chosen for accessing this table.
>  >
>
> ...