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From "Edward J. Yoon" <edwardy...@apache.org>
Subject Re: About the table on time dimension.
Date Fri, 22 May 2009 08:00:44 GMT
Hey,

The different rows are in other table version. I think the 'versions'
is the table property, not row property.

On Fri, May 22, 2009 at 4:33 PM, Ryan Rawson <ryanobjc@gmail.com> wrote:
> Hey,
>
> those 2 entries have different rows ids, with different timestamps (same
> column, same value).
>
> btw, setting timestamps in a non-monotonically increasing order may cause
> performance and certain correctness issues on 0.20.  Best to avoid it for
> production code if you can.
>
> On Fri, May 22, 2009 at 12:27 AM, Edward J. Yoon <edwardyoon@apache.org>wrote:
>
>> OK, It's my typos, not my point. Result is same even if 'versions' is
>> 1. Anyway, Do you think 'version mixed' table should be appeared?
>>
>> hbase(main):025:0> describe 't1'
>> {NAME => 't1', IS_ROOT => 'false', IS_META => 'false', FAMILIES =>
>> [{NAME => 'f1', BLOOMFILTER => 'false', COM
>> PRESSION => 'NONE', VERSIONS => '1', LENGTH => '2147483647', TTL =>
>> '-1', IN_MEMORY => 'false', BLOCKCACHE =>
>> 'false'}], INDEXES => []}
>> 1 row(s) in 0.0230 seconds
>> hbase(main):028:0> scan 't1'
>> ROW                          COLUMN+CELL
>>  r1                          column=f1:, timestamp=1, value=value
>>  r2                          column=f1:, timestamp=3, value=value
>> 2 row(s) in 0.0240 seconds
>>
>> On Fri, May 22, 2009 at 3:41 PM, Ryan Rawson <ryanobjc@gmail.com> wrote:
>> > Hey,
>> >
>> > I generally don't think of hbase entries like spreadsheets with 'nulls'
>> in
>> > the empty locations.  Its really more like an adjacency list, where the
>> data
>> > is only there when it's there.
>> >
>> > But I was referring to your create, the key is 'VERSIONS' not 'VERSION'.
>> > create 'table', {NAME=>'family', VERSIONS=>1}
>> >
>> >
>> >
>> > On Thu, May 21, 2009 at 11:35 PM, Edward J. Yoon <edwardyoon@apache.org
>> >wrote:
>> >
>> >> Let's assume, there are two 2 * 2 sparse tables as below.
>> >>
>> >> t1
>> >> ----
>> >> null 2
>> >> -1 null
>> >>
>> >> t2
>> >> ----
>> >> -3 null
>> >> null null
>> >>
>> >> I'll put these tables to table 'x'. And, The table 'x' will handle
>> >> only one version. Then, 't2' should be appeared, not 't1' + 't2'
>> >> table.
>> >>
>> >> Currently, Hbase shows the 't1' + 't2' table as below.
>> >> ----
>> >> -3(t2) 2(t1)
>> >> -1(t1) null (what is this?)
>> >>
>> >> Should I update the all 't1' entries?
>> >>
>> >> On Fri, May 22, 2009 at 3:11 PM, Ryan Rawson <ryanobjc@gmail.com>
>> wrote:
>> >> > The key is 'VERSIONS'.  Give it another shot.
>> >> >
>> >> > -ryan
>> >> >
>> >> > On Thu, May 21, 2009 at 11:07 PM, Edward J. Yoon <
>> edwardyoon@apache.org
>> >> >wrote:
>> >> >
>> >> >> hbase(main):001:0> create 't1', {NAME=> 'f1', VERSION =>
1}
>> >> >> hbase(main):002:0> put 't1', 'r1', 'f1' ,'value', 1
>> >> >> hbase(main):007:0> put 't1', 'r2', 'f1:' ,'value', 2
>> >> >>
>> >> >> I made a table 't1' as above. And, When scan this,
>> >> >>
>> >> >> hbase(main):008:0> scan 't1'
>> >> >> ROW                          COLUMN+CELL
>> >> >>  r1                          column=f1:, timestamp=1,
value=value
>> >> >>  r2                          column=f1:, timestamp=2,
value=value
>> >> >> 2 row(s) in 0.0330 seconds
>> >> >>
>> >> >> I expected only one row 'r2' (sparse table for time t2) but there
are
>> >> >> two tables on time dimension. I think it's a logical bug. The 't1'
>> >> >> should maintain only one version of time dimension table.
>> >> >>
>> >> >> What do you think?
>> >> >> --
>> >> >> Best Regards, Edward J. Yoon @ NHN, corp.
>> >> >> edwardyoon@apache.org
>> >> >> http://blog.udanax.org
>> >> >>
>> >> >
>> >>
>> >>
>> >>
>> >> --
>> >> Best Regards, Edward J. Yoon @ NHN, corp.
>> >> edwardyoon@apache.org
>> >> http://blog.udanax.org
>> >>
>> >
>>
>>
>>
>> --
>> Best Regards, Edward J. Yoon @ NHN, corp.
>> edwardyoon@apache.org
>> http://blog.udanax.org
>>
>



-- 
Best Regards, Edward J. Yoon @ NHN, corp.
edwardyoon@apache.org
http://blog.udanax.org

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