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From Christian Decker <>
Subject Re: LongType from user input
Date Fri, 24 Sep 2010 20:10:03 GMT
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? :-)


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 I
>>>> 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 ID
>>>> they'd like, I was about to turn to UTF8, when I remembered that they are
>>>> compared lexicographically, so that 100 actually comes before 2, which kills
>>>> 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 read
>>>> into 8bytes isn't going to work either.
>>>> Any tricks for this one?
>>>> Regards,
>>>> Chris

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