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From Michaela Buergle <Michaela.Buer...@neofonie.de>
Subject Re: Save lists relating to records
Date Wed, 09 Apr 2008 08:53:40 GMT
Ok, once again HQL got me confused :)
I just found out that I can easily get all columns for a family via the
API by just passing "familyName:" as an argument. Before, I thought it
was necessary to explicitly name each column because that is the case
from within the HQL shell.
Considering that, the multi-column approach will clearly be the favorite
for my list.

I think the HBase documentation could be more explicit on the subject of
column families/columns.

micha

Bryan Duxbury wrote:
> If you are using the getRow method, then you can get the whole row
> (including your list column) all at once. There is also an overload that
> allows you to select a desired subset of columns.
> -Bryan
> 
> On Apr 8, 2008, at 8:47 AM, Michaela Buergle wrote:
> 
>> Thanks for your remarks!
>> The multi-column approach does seem more HBase-y. I'm concerned however
>> about performance when retrieving a large number of columns in order to
>> get the whole list per record. What do you think?
>>
>> micha
>>
>> Bryan Duxbury wrote:
>>> I think the approach of using a column family for the list and a column
>>> for each element is the way to go. It seems to be the most HBase-y way
>>> to lay the schema out.
>>>
>>> You can of course use multiple tables if you want, but we have no joins
>>> of any kind implemented in HBase, so it'd be up to you to perform the
>>> join yourself in application code.
>>>
>>> Custom formatting would work too, but then you pay the cost of being
>>> unable to look at and add manipulate items in the list individually, so
>>> I'd also stay away from that.
>>>
>>> -Bryan
>>>
>>> On Apr 8, 2008, at 8:17 AM, Michaela Buergle wrote:
>>>
>>>> Hi all,
>>>> I'm planning to save (and retrieve) potentially very long lists of
>>>> values, each list relating to one row in my HBase table. Have any of
>>>> you
>>>> tried something similar with HBase?
>>>>
>>>> Possible approaches that come to mind are:
>>>> - Insert a new row for each list item, duplicate the rest
>>>> - Create a column family for the list and insert each list item into a
>>>> new column in this family
>>>> - Write the whole list into one cell using custom formatting
>>>> - Use several tables + perform some kind of join
>>
> 

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