On 07/13/2011 02:34 PM, Timour Katchaounov wrote: > Igor, > > Could you please review this fix for bug lp:809266.
Timour, If you have full coverage of the new code from the patch then you may push it. Regards, Igor. > > Timour > > ------------------------------------------------------------ > revno: 3104 > revision-id: tim...@askmonty.org-20110713211507-j9v80yk2tzae8tq2 > parent: tim...@askmonty.org-20110713141146-339e3xwz17hogqsb > fixes bug(s): https://launchpad.net/bugs/809266 > committer: tim...@askmonty.org > branch nick: 5.3-mwl89 > timestamp: Thu 2011-07-14 00:15:07 +0300 > message: > Fix bug lp:809266 > > Analysis: > This is a bug in MWL#68, where it was incorrectly assumed > that if there is a match in the only non-null key, then > if there is a covering NULL row on all remaining NULL-able > columns there is a partial match. However, this is not the case, > because even if there is such a null-only sub-row, it is not > guaranteed to be part of the matched sub-row. The matched sub-row > and the NULL-only sub-row may be parts of different rows. > > In fact there are two cases: > - there is a complete row with only NULL values, and > - all nullable columns contain only NULL values. > > These two cases were incorrectly mixed up in the class member > subselect_partial_match_engine::covering_null_row_width. > > > Solution: > The solution is to: > - split covering_null_row_width into two members: > has_covering_null_row, and has_covering_null_columns, and > - take into account each state during initialization and > execution. _______________________________________________ Mailing list: https://launchpad.net/~maria-developers Post to : maria-developers@lists.launchpad.net Unsubscribe : https://launchpad.net/~maria-developers More help : https://help.launchpad.net/ListHelp