Re: Using doubles and longs as ordering row values

[David Koch <og...@googlemail.com>]

Hello Lars,

Thank you. Where can I find the lily library? I can't find it on github or
Google.

/David


On Fri, Nov 30, 2012 at 3:54 AM, lars hofhansl <lh...@yahoo.com> wrote:

> As I said, look at the lily library they have solved exactly that problem,
> I've used that before.
>
> It has encodings for Ints/Longs/Floats/Doubles/BigDecimals, to encode them
> such the byte array will sort according to the magnitude of the value which
> includes the sign and the floating point exponent.
>
> It's a very common problem :)
>
>
> -- Lars
>
>
>
> ----- Original Message -----
> From: David Koch <og...@googlemail.com>
> To: user@hbase.apache.org
> Cc:
> Sent: Thursday, November 29, 2012 3:00 PM
> Subject: Re: Using doubles and longs as ordering row values
>
> Hello,
>
> I am having a similar issue, only I need to preserve the order of
> qualifiers which are serialized signed longs - rather than row keys. The
> latter is addressed by the orderly library which was mentioned above. Can
> this library be re-used for my purpose? I imagine this is not an exotic
> requirement so I am also interested in knowing how other people have solved
> this problem.
>
> Thank you,
>
> /David
>
>
> On Tue, Nov 6, 2012 at 6:07 AM, Jonathan Bishop <jbishop.rwc@gmail.com
> >wrote:
>
> > Thanks Dave,
> >
> > That looks like what I need.
> >
> > Jon
> >
> >
> > On Mon, Nov 5, 2012 at 4:27 PM, Dave Latham <la...@davelink.net> wrote:
> >
> > > This fork looks a bit more up to date:
> > > https://github.com/ndimiduk/orderly
> > >
> > > On Mon, Nov 5, 2012 at 4:26 PM, Dave Latham <la...@davelink.net>
> wrote:
> > >
> > > > Here's a project to deal with this issue specifically.  I'm not sure
> of
> > > > it's status:
> > > > https://github.com/conikeec/orderly
> > > >
> > > >
> > > > On Mon, Nov 5, 2012 at 4:01 PM, lars hofhansl <lh...@yahoo.com>
> > > wrote:
> > > >
> > > >> Have a look at the lily library. It has code to encode Longs/Doubles
> > > into
> > > >> bytes such that resulting bytes sort as expected based on the
> numbers.
> > > >>
> > > >> -- Lars
> > > >>
> > > >>
> > > >>
> > > >> ________________________________
> > > >>  From: Jonathan Bishop <jb...@gmail.com>
> > > >> To: "user@hbase.apache.org" <us...@hbase.apache.org>
> > > >> Sent: Monday, November 5, 2012 10:41 AM
> > > >> Subject: Using doubles and longs as ordering row values
> > > >>
> > > >> Hi,
> > > >>
> > > >> In my application my row values are doubles. I would like my scans
> to
> > > >> traverse the rows in order of increasing values.
> > > >>
> > > >> But if I simply use
> > > >>
> > > >> double d  = ....
> > > >> byte[] row = Bytes.toBytes(d);
> > > >>
> > > >> I will get an ordering which is based on the byte values of doubles,
> > not
> > > >> on
> > > >> the value of the doubles themselves.
> > > >>
> > > >> I see also that integer values have the same issue due to the first
> > bit
> > > >> being the sign bit. So negative values will come after positive
> > values.
> > > >>
> > > >> Any suggestions?
> > > >>
> > > >> Thanks,
> > > >>
> > > >> Jon
> > > >>
> > > >
> > > >
> > >
> >
>
>

Re: Using doubles and longs as ordering row values

[Marcos Ortiz <ml...@uci.cu>]

On 12/01/2012 10:01 AM, David Koch wrote:
> Hello Lars,
>
> Thank you. Where can I find the lily library? I can't find it on github or
> Google.
http://www.lilyproject.org/lily/index.html
>
> /David
>
>
> On Fri, Nov 30, 2012 at 3:54 AM, lars hofhansl <lh...@yahoo.com> wrote:
>
>> As I said, look at the lily library they have solved exactly that problem,
>> I've used that before.
>>
>> It has encodings for Ints/Longs/Floats/Doubles/BigDecimals, to encode them
>> such the byte array will sort according to the magnitude of the value which
>> includes the sign and the floating point exponent.
>>
>> It's a very common problem :)
>>
>>
>> -- Lars
>>
>>
>>
>> ----- Original Message -----
>> From: David Koch <og...@googlemail.com>
>> To: user@hbase.apache.org
>> Cc:
>> Sent: Thursday, November 29, 2012 3:00 PM
>> Subject: Re: Using doubles and longs as ordering row values
>>
>> Hello,
>>
>> I am having a similar issue, only I need to preserve the order of
>> qualifiers which are serialized signed longs - rather than row keys. The
>> latter is addressed by the orderly library which was mentioned above. Can
>> this library be re-used for my purpose? I imagine this is not an exotic
>> requirement so I am also interested in knowing how other people have solved
>> this problem.
>>
>> Thank you,
>>
>> /David
>>
>>
>> On Tue, Nov 6, 2012 at 6:07 AM, Jonathan Bishop <jbishop.rwc@gmail.com
>>> wrote:
>>> Thanks Dave,
>>>
>>> That looks like what I need.
>>>
>>> Jon
>>>
>>>
>>> On Mon, Nov 5, 2012 at 4:27 PM, Dave Latham <la...@davelink.net> wrote:
>>>
>>>> This fork looks a bit more up to date:
>>>> https://github.com/ndimiduk/orderly
>>>>
>>>> On Mon, Nov 5, 2012 at 4:26 PM, Dave Latham <la...@davelink.net>
>> wrote:
>>>>> Here's a project to deal with this issue specifically.  I'm not sure
>> of
>>>>> it's status:
>>>>> https://github.com/conikeec/orderly
>>>>>
>>>>>
>>>>> On Mon, Nov 5, 2012 at 4:01 PM, lars hofhansl <lh...@yahoo.com>
>>>> wrote:
>>>>>> Have a look at the lily library. It has code to encode Longs/Doubles
>>>> into
>>>>>> bytes such that resulting bytes sort as expected based on the
>> numbers.
>>>>>> -- Lars
>>>>>>
>>>>>>
>>>>>>
>>>>>> ________________________________
>>>>>>   From: Jonathan Bishop <jb...@gmail.com>
>>>>>> To: "user@hbase.apache.org" <us...@hbase.apache.org>
>>>>>> Sent: Monday, November 5, 2012 10:41 AM
>>>>>> Subject: Using doubles and longs as ordering row values
>>>>>>
>>>>>> Hi,
>>>>>>
>>>>>> In my application my row values are doubles. I would like my scans
>> to
>>>>>> traverse the rows in order of increasing values.
>>>>>>
>>>>>> But if I simply use
>>>>>>
>>>>>> double d  = ....
>>>>>> byte[] row = Bytes.toBytes(d);
>>>>>>
>>>>>> I will get an ordering which is based on the byte values of doubles,
>>> not
>>>>>> on
>>>>>> the value of the doubles themselves.
>>>>>>
>>>>>> I see also that integer values have the same issue due to the first
>>> bit
>>>>>> being the sign bit. So negative values will come after positive
>>> values.
>>>>>> Any suggestions?
>>>>>>
>>>>>> Thanks,
>>>>>>
>>>>>> Jon
>>>>>>
>>>>>
>>
>
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-- 

Marcos Luis Ortíz Valmaseda
about.me/marcosortiz <http://about.me/marcosortiz>
@marcosluis2186 <http://twitter.com/marcosluis2186>



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CONECTADOS AL FUTURO, CONECTADOS A LA REVOLUCION

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