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From:Jay Pipes Date:June 8 2009 5:04pm
Subject:Re: Value objects and Protocol (WL#4760)
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Jay Pipes wrote:
> Michael Widenius wrote:
>> Hi!
>>
>>>>>>> "Oystein" == Oystein Grovlen <ystein> writes:
>>
>> Oystein> Konstantin Osipov wrote:
>>>> * Øystein Grøvlen <Oystein.Grovlen@stripped> [09/05/22
> 21:05]:
>>>>> So far my Value object knows nothing about arithmetics, all they 
>>>>> know  about is how to convert between types.  However, it needs to 
>>>>> distinguish  between more than just four types.  For example, 
>>>>> conversion between  integer and string will be different for a 
>>>>> Field_timestamp than for a  Field_long.
>>>> This just doesn't make sense to me. It's like saying that
>>>> conversion between an integer and a string will be different
>>>> depending whether this integer represents a datetime or, well, an
>>>> integer.
>>>> Isn't it easier to say (and code) that a conversion from an
>>>> integer to a string is not the same as conversion from a datetime to
>>>> a string?  What am I missing?
>>
>> Oystein> That's really what I tried to say.  Both integer and datetime 
>> will Oystein> internally be represented by a longlong, but the 
>> conversion from Oystein> longlong to string will be different.
>>
>> Plese don't do that!
>>
>> We want to add microsecond support to datetime and having datetime as
>> longlong would make this quite hard to do!
> 
> Not really.  Lay the bits out like so:
> 
> | 63 | 62 | 61 | 60 | 59 | 58 | 57 | 56 |
> | JD | JD | JD | JD | JD | JD | JD | JD |
> | 55 | 54 | 53 | 52 | 51 | 50 | 49 | 48 |
> | JD | JD | JD | JD | JD | JD | JD | JD |
> | 47 | 46 | 45 | 44 | 43 | 42 | 41 | 40 |
> | JD | JD | JD | JD | JD | JD | JD | JD |
> | 39 | 38 | 37 | 36 | 35 | 34 | 33 | 32 |
> | JD | JD | JD | uS | uS | uS | uS | uS |
> 
> | 31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 |
> | uS | uS | uS | uS | uS | uS | uS | uS |
> | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 |
> | uS | uS | uS | uS | uS | uS | uS | SS |
> | 15 | 14 | 13 | 12 | 11 | 10 | 09 | 08 |
> | SS | SS | SS | SS | SS | SS | SS | SS |
> | 07 | 06 | 05 | 04 | 03 | 02 | 01 | 00 |
> | SS | SS | SS | SS | SS | SS | SS | SS |

Actually, come to think of it, storing microseconds in the lowest bits 
would be even better, since temporal values could be compared directly 
as uint64_t's ...

> Where:
> 
> JD = Julian Day Number
> uS = microseconds up to 1,000,000
> SS = seconds in day up to 86400
> 
> Julian Day Number stored in 27 bits will limit the capacity of the field 
> to -4713 B.C to July 23rd, 362763 A.D. but I think that's sufficient :)
> 
> Cheers,
> 
> Jay
> 

Thread
Value objects and Protocol (WL#4760)Øystein Grøvlen22 May
  • Re: Value objects and Protocol (WL#4760)Konstantin Osipov22 May
    • Re: Value objects and Protocol (WL#4760)Alex Esterkin22 May
      • Re: Value objects and Protocol (WL#4760)Brian Aker22 May
        • Re: Value objects and Protocol (WL#4760)Alex Esterkin22 May
          • Re: Value objects and Protocol (WL#4760)Brian Aker22 May
          • Re: Value objects and Protocol (WL#4760)Sergei Golubchik23 May
        • Re: Value objects and Protocol (WL#4760)Konstantin Osipov23 May
          • Re: Value objects and Protocol (WL#4760)Brian Aker23 May
    • Re: Value objects and Protocol (WL#4760)Øystein Grøvlen22 May
      • Re: Value objects and Protocol (WL#4760)Konstantin Osipov22 May
        • Re: Value objects and Protocol (WL#4760)Alex Esterkin22 May
          • Re: Value objects and Protocol (WL#4760)Øystein Grøvlen25 May
        • Re: Value objects and Protocol (WL#4760)Øystein Grøvlen24 May
          • Re: Value objects and Protocol (WL#4760)Konstantin Osipov24 May
      • Re: Value objects and Protocol (WL#4760)Konstantin Osipov23 May
        • Re: Value objects and Protocol (WL#4760)Øystein Grøvlen25 May
          • Re: Value objects and Protocol (WL#4760)Michael Widenius6 Jun
            • Re: Value objects and Protocol (WL#4760)Øystein Grøvlen8 Jun
            • Re: Value objects and Protocol (WL#4760)Jay Pipes8 Jun
              • Re: Value objects and Protocol (WL#4760)Jay Pipes8 Jun
  • Re: Value objects and Protocol (WL#4760)Jay Pipes24 May
    • Re: Value objects and Protocol (WL#4760)Øystein Grøvlen25 May
      • Re: Value objects and Protocol (WL#4760)Jay Pipes26 May
    • Re: [Drizzle-discuss] Value objects and Protocol (WL#4760)Jim Starkey28 May
Re: Value objects and Protocol (WL#4760)Brian Aker22 May