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From Christian Decker <>
Subject Re: LongType from user input
Date Sun, 26 Sep 2010 14:11:31 GMT
Hi Aaron,

what changes can I expect in the 0.7 release regarding Comparison and
Parameters? My problem is mainly that I want to take Strings from stdin (or
Pig Scripts for that matter) and convert them in such a way that they are
interpreted correctly and converted to the corresponding byte representation
to use them in column names and keys.


On Sun, Sep 26, 2010 at 5:20 AM, Aaron Morton <>wrote:

> Things a changing in v0.7, the row keys are byte arrays.
> Not sure I understand your other concerns.
> Aaron
> On 25 Sep 2010, at 08:10, Christian Decker <>
> wrote:
> Thanks for your quick answer, I think I'll use an affix to sort of cast the
> keys, ranges and others from their textual representation (from Pig) to the
> desired byte representation, since I just noticed that the keys for the rows
> themselfs are always UTF8 interpreted, and since I want to make key-range as
> well as slice queries, I'll be better off this way I think. I'll just add a
> 'L' for Long and 'U' for UUID (of any kind).
>  Or is there a better way that I just can't see from my beginners angle?
> :-)thing
> Regards,
> Chris
> On Fri, Sep 24, 2010 at 6:35 PM, Tyler Hobbs < <>
>> wrote:
>> Yes, you can use describe_keyspace() and then look through the results.
>> It's a little ugly in 0.6, but it works.
>> - Tyler
>> On Fri, Sep 24, 2010 at 11:25 AM, Christian Decker <<>
>>> wrote:
>>> Well I'm writing a loading function for Pig, and as it happens I want to
>>> be able to load slices from cassandra which are specified in the pig script
>>> (thus the input from stdin) but the ColumnFamily from which to read the data
>>> is another parameter and some of the CFs have UTF8, UUID, TimeUUID or Long
>>> types for their keys and columns, so simply converting everything I get to
>>> an 8byte long would break compatibility with the others.
>>> Now thinking about it I attacked the whole problem in a weird way, since
>>> UUID types won't work either.
>>> So let me change my question slightly, is there a way in 0.6 to detect
>>> the compareWith type on a running cluster? That way I could convert it to
>>> the right type :D
>>> Regards,
>>> Chris
>>> On Fri, Sep 24, 2010 at 6:09 PM, Tyler Hobbs < <>
>>>> wrote:
>>>> I'm not sure I understand why using this with multiple column families
>>>> prevents you from converting it.  Could you clarify this?
>>>> On Fri, Sep 24, 2010 at 10:56 AM, Christian Decker <<>
>>>>> wrote:
>>>>> Hi all,
>>>>> I'm having quite a dilemma with the CompareWith attribute. The Problem
>>>>> is that I have numeric IDs that I'd like to use as row keys, only that
>>>>> also have to offer a possibility to let users input them from std input.
>>>>> Since I cannot ask my users to input an 8byte sequence representing the
>>>>> they'd like, I was about to turn to UTF8, when I remembered that they
>>>>> compared lexicographically, so that 100 actually comes before 2, which
>>>>> key slices. Also I cannot just code a converter in since this is supposed
>>>>> be a used with multiple columnfamilies, so just converting an integer
>>>>> into 8bytes isn't going to work either.
>>>>> Any tricks for this one?
>>>>> Regards,
>>>>> Chris

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