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From:Alexander Barkov Date:December 8 2008 7:50pm
Subject:Re: Please review fox for bug#34479
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Hi Vladislav,

Vladislav Vaintroub wrote:
> Bar,
> I believe there is nothing with Falcon internals. Prior solution seems to be
> a kludge, some workaround, possibly insufficient understanding of what one
> could do with strings library. IMO Falcon relies on MySQL collation for
> comparison and fail to see why on earth should we removing nowhere
> documented minChar.
> But I might of course be wrong , if so Ann and Jim, please correct my
> understanding of what's going on.

I don't know if the problem is with Falcon itself, or with some
other part. It can also be handler API problem, or problems in
other parts of MySQL.

I just only state that it's not correct to remove minChar,
because you don't know if the character was padded or the
character is a real part of the string.


> 
> 
> 
>> -----Original Message-----
>> From: Alexander.Barkov@stripped [mailto:Alexander.Barkov@stripped]
>> Sent: Monday, December 08, 2008 8:33 PM
>> To: Lars-Erik Bjørk
>> Cc: Ann W. Harrison; Kevin Lewis; falcon@stripped;
>> svoj@stripped
>> Subject: Re: Please review fox for bug#34479
>>
>> Hi Lars-Erik,
>>
>> Lars-Erik Bjørk wrote:
>>> Just to make sure that I understand things correctly :)
>>>
>>> The trailing spaces (and minimum sort characters) I have been
>> removing
>>> so far, I have converted to the given character set, so for f.eks
>> UCS2,
>>> I have been looking to remove 0x0020, etc
>>>
>>> Should it be done like this for trailing zeros as well, so that I in
>> the
>>> case of ucs2 should be looking to remove 0x0000?
>> I cannot answer for Falcon internals.
>> In case you really need to remove BOTH zeros and MinChars,
>> I suggest to add a new function into MY_CHARSET_HANDLER, so
>> you do this with highest performance, without having to
>> convert between character sets.
>>
>>> Also, if I try to remove only spaces (pad chars) and zeros, but not
>> the
>>> minimum sort character, some queries using LIKE comparison in the
>> Falcon
>>> suite starts failing.
>> I'm not sure but I think it should be re-designed a little bit.
>> It is not good to pad a string to have truncate it later.
>> A better ways for my opinion would be to pass the correct string
>> length into appropriate functions.
>>
>>> Kevin is correct btw, that bug#23692 has not been prioritized because
>> it
>>> does not have a BETA tag.
>>>
>>> /Lars-Erik
>>>
>>>
>>> On Wed, 2008-12-03 at 14:36 -0500, Ann W. Harrison wrote:
>>>> Alexander Barkov wrote:
>>>>
>>>>> That's true , <tab> in many collations is the smallest
> character
>>>>> (i.e. minSortChar=<tab>), and space is greater than
> <tab>.
>>>>>
>>>>> So does not seem correct to remove both spaces and tabs, and
>>>>> then execute strnncoll() for the results in the patch for
>>>>> bug#34479.
>>>>>
>>>> You're absolutely right.
>>>>
>>>> We should not remove tabs, but only spaces.  I don't know what
>>>> the code does currently, but the original design (not necessarily
>>>> its implementation) removed only spaces.  (And, of course, trailing
>>>> zeros for numerics, but that's another topic.)
>>>>
>>>> Best regards,
>>>>
>>>>
>>>> Ann
>>
>> --
>> Falcon Storage Engine Mailing List
>> For list archives: http://lists.mysql.com/falcon
>> To unsubscribe:    http://lists.mysql.com/falcon?unsub=1
> 
> 

Thread
Please review fox for bug#34479Lars-Erik Bjørk2 Dec
  • RE: Please review fox for bug#34479Vladislav Vaintroub2 Dec
    • RE: Please review fox for bug#34479Lars-Erik Bjørk2 Dec
      • RE: Please review fox for bug#34479Lars-Erik Bjørk2 Dec
        • Re: Please review fox for bug#34479Alexander Barkov3 Dec
          • Re: Please review fox for bug#34479Lars-Erik Bjørk3 Dec
            • Re: Please review fox for bug#34479Kevin Lewis3 Dec
              • Re: Please review fox for bug#34479Ann W. Harrison3 Dec
    • Re: Please review fox for bug#34479Ann W. Harrison2 Dec
      • RE: Please review fox for bug#34479Vladislav Vaintroub2 Dec
Re: Please review fox for bug#34479Kevin Lewis3 Dec
  • Re: Please review fox for bug#34479Alexander Barkov3 Dec
    • Re: Please review fox for bug#34479Ann W. Harrison3 Dec
      • Re: Please review fox for bug#34479Lars-Erik Bjørk4 Dec
        • RE: Please review fox for bug#34479Vladislav Vaintroub4 Dec
        • Re: Please review fox for bug#34479Lars-Erik Bjørk4 Dec
          • RE: Please review fox for bug#34479Vladislav Vaintroub4 Dec
          • Re: Please review fox for bug#34479Ann W. Harrison4 Dec
        • Re: Please review fox for bug#34479Ann W. Harrison4 Dec
          • Re: Please review fox for bug#34479Lars-Erik Bjørk5 Dec
            • Re: Please review fox for bug#34479Lars-Erik Bjørk5 Dec
        • Re: Please review fox for bug#34479Alexander Barkov8 Dec
          • RE: Please review fox for bug#34479Vladislav Vaintroub8 Dec
            • Re: Please review fox for bug#34479Alexander Barkov8 Dec
            • Re: Please review fox for bug#34479Ann W. Harrison8 Dec
Re: Please review fox for bug#34479Ann W. Harrison4 Dec