From: Guilhem Bichot
Date: January 11 2011 11:15am
Subject: Re: bzr commit into mysql-next-mr-bugfixing branch (jorgen.loland:3242)
 WL#4800
List-Archive: http://lists.mysql.com/commits/128410
Message-Id: <4D2C3BBF.6070600@oracle.com>
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Hello,

Jorgen Loland a écrit, Le 05.01.2011 14:26:
> Guilhem,
> 
> I think patching a broken diff-file has played a trick on you regarding 
> the questions below

yes

> (the comments I have removed are valid).

yes

  I will give
> commit another try so you can get a proper bundle.

Thanks, will send a review of that latest patch.

> On 01/04/2011 03:03 PM, Guilhem Bichot wrote:
>> Hello,
>>
>> First, I'm grateful that you took the time to fix all issues; I see
>> there were quite a few in my own code :-/
> ...
>>> === modified file 'mysql-test/r/optimizer_trace_no_prot.result'
>>> @@ -1561,12 +1688,12 @@ explain extended select * from t1 where },
>>> {
>>> "attaching_conditions_to_tables": {
>>> - "original_condition": null,
>>> + "original_condition": "<nop>((`test`.`t1`.`s1` > (/* select#2 */
>>> select min(`test`.`t1`.`s2`) from `test`.`t1`)))",
>>
>> It's not obvious in this diff, but this block (like 1641 in the result
>> file after the patch) belongs to select#2 (subquery) so it's not normal
>> that its "original_condition" is now "<nop>(t1.s1>(select#2 etc": that
>> is surely a condition for select#1. There is a problem.
>>
>>> "attached_conditions": [
>>> {
>>> "database": "test",
>>> "table": "t1",
>>> - "attached": null
>>> + "attached": "<nop>((`test`.`t1`.`s1` > (/* select#2 */ select
>>> min(`test`.`t1`.`s2`) from `test`.`t1`)))"
>>> }
>>> ] /* attached_conditions */
>>> } /* attaching_conditions_to_tables */
>>
>>> @@ -3436,12 +3647,12 @@ concat(c1,'y') IN
>>> },
>>> {
>>> "attaching_conditions_to_tables": {
>>> - "original_condition": null,
>>> + "original_condition":
>>> "(<in_optimizer>(concat(`test`.`t1`.`c1`,'x'),concat(`test`.`t1`.`c1`,'x') 
>>>
>>> in (/* select#2 */ select left(`test`.`t2`.`c2`,8) from `test`.`t2`))
>>> and
>>> <in_optimizer>(concat(`test`.`t1`.`c1`,'y'),concat(`test`.`t1`.`c1`,'y')
>>> in (/* select#3 */ select left(`test`.`t2`.`c2`,9) from `test`.`t2`)))",
>>> "attached_conditions": [
>>> {
>>> "database": "test",
>>> - "table": "t2",
>>> - "attached": null
>>> + "table": "t1",
>>
>> This change from t2 to t1 is not normal: this block (line 3651 of the
>> result file after the patch) is for select#2 (subquery) which doesn't
>> contain t1.
>>
>>> + "attached":
>>> "(<in_optimizer>(concat(`test`.`t1`.`c1`,'x'),concat(`test`.`t1`.`c1`,'x') 
>>>
>>> in (/* select#2 */ select left(`test`.`t2`.`c2`,8) from `test`.`t2`))
>>> and
>>> <in_optimizer>(concat(`test`.`t1`.`c1`,'y'),concat(`test`.`t1`.`c1`,'y')
>>> in (/* select#3 */ select left(`test`.`t2`.`c2`,9) from `test`.`t2`)))"
>>> }
>>> ] /* attached_conditions */
>>> } /* attaching_conditions_to_tables */
>>
>>> @@ -4150,13 +4473,117 @@ select * from t1 where (t1.a,t1.b) not i
>>> "refine_plan": [
>>> {
>>> "database": "test",
>>> - "table": "t2",
>>> + "table": "t1",
>>
>> not normal
>>
> 


-- 
Mr. Guilhem Bichot <guilhem.bichot@stripped>
Oracle / MySQL / Optimizer team, Lead Software Engineer
Bordeaux, France
www.oracle.com / www.mysql.com