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From Jonathan Ellis <>
Subject Re: (another) Newbie question
Date Sat, 17 Apr 2010 05:54:09 GMT
The important distinction here is that you can slice on columns in a
row, but you can't slice on column family (or keyspace) names, because
the data isn't stored contiguously.  The row, within the columnfamily,
is the unit of data storage and api focus.

On Sat, Apr 17, 2010 at 12:42 AM, Benjamin Black <> wrote:
> The multi-level dictionary explanation holds.  Regex on keys like that
> is something specific language implementations support, not something
> inherent in a dictionary data structure.  The table model is
> particularly fraught because it drags in a lot of relational
> assumptions, none of which hold.  And I am not suggesting renaming
> anything :)
> b
> On Fri, Apr 16, 2010 at 3:08 PM, Jonathan Ellis <> wrote:
>> On Mon, Apr 12, 2010 at 9:48 AM, Colin Yates <> wrote:
>>> I was hoping I could do a get_range_slices specifying 'project*' for the
>>> columnFamily and a keyRange start: 20100107, end:20100109 but I
>>> get an error 'InvalidRequestException(why:unconfigured columnfamily project*)'.
>> I think you've been misled by the "think of Cassandra as a multi-level
>> hash" explanations; you can't wildcard ColumnFamilies like that.  (I
>> personally think that the model of "a columnfamily is like a table,
>> except that its rows can contain nested columns [supercolumns]" is
>> more useful.)
>> -Jonathan

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