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From Hafiz Mujadid <hafizmujadi...@gmail.com>
Subject Re: passing hbase scan start row in spark_phoenix
Date Tue, 11 Aug 2015 19:16:45 GMT
Hi Yuhao!

Why record number 6 should be omitted?

On Tue, Aug 11, 2015 at 9:08 PM, Yuhao Bi <byh0831@gmail.com> wrote:

> Hi,
>
> 1.Image we create the test table with following sql:
> CREATE TABLE library (
>   title varchar not null,
>   author varchar not null,
>   isbn varchar not null,
>   published_date integer,
>   description varchar,
>   CONSTRAINT pk PRIMARY KEY(title, author, isbn)
> )
>
> 2.After insert some test data, our table may looks like,
>
>        title   author  isbn    published_date  description
> 1    aaa1    aaa     aaa     2010            NULL
> 2    aaa2    aaa     aaa     2008            NULL
> 3    aaa3    aaa     aaa     2007            NULL
> 4    bbb1    aaa     bbb     2009            NULL
> 5    ccc1    aaa     ccc     2011            NULL
> 6    ccc2    bbb     ccc     2012            NULL
> 7    ccc3    bbb     ccc     2006            NULL
> 8    ccc4    bbb     ccc     2014            NULL
>
> 3.Then we use the query sql (from http://phoenix.apache.org/paged.html)
>    SELECT title, author, isbn, description
>        FROM library
>            WHERE published_date > 2010
>            AND (title, author, isbn) > (?, ?, ?)       //this row value
> constructors will specify the start row
>         ORDER BY title, author, isbn                 //In our case ORDER
> BY is ignored (CONSTRAINT pk PRIMARY KEY(title, author, isbn))
>    LIMIT 20
>
>     1) SELECT title, author, isbn, description FROM library WHERE
> published_date > 2010 LIMIT 20;
>         should return:
>                title   author  isbn    published_date  description
>          1    aaa1    aaa     aaa     2010            NULL
>          5    ccc1    aaa     ccc     2011            NULL
>          6    ccc2    bbb     ccc     2012            NULL
>          8    ccc4    bbb     ccc     2014            NULL
>     2)SELECT title, author, isbn, description FROM library WHERE
> published_date > 2010
>        AND (title, author, isbn) > ('ccc1', 'aaa', 'ccc')    //this means
> we skip all rows in front of "record 5"(ccc2    bbb     ccc     2012
>      NULL)
>
>         //and return matched records below "record 5" (exclude)
>        LIMIT 20;
>         should return:
>         7    ccc2    bbb     ccc     2012            NULL
>         8    ccc4    bbb     ccc     2014            NULL
>
>
> Sorry I dont't have a running cluster around, correct me if I was wrong.
> :)
>
>
> Thanks.
>
>
>
> 2015-08-11 22:43 GMT+08:00 Hafiz Mujadid <hafizmujadid00@gmail.com>:
>
>> Yes I want to do pagination and I am confused how to achieve pagination?
>>
>> On Tue, Aug 11, 2015 at 7:08 PM, Yuhao Bi <byh0831@gmail.com> wrote:
>>
>>> Hi,
>>>
>>> Here is some official document which may help.
>>>
>>> 1.    http://phoenix.apache.org/skip_scan.html
>>> 2.    Wanna do some Pagination-like scan?
>>>      Please refer to  http://phoenix.apache.org/paged.html
>>>
>>> Thanks.
>>>
>>> 2015-08-11 20:47 GMT+08:00 Hafiz Mujadid <hafizmujadid00@gmail.com>:
>>>
>>>> Hi all!
>>>>
>>>>
>>>> Can we use spark_phoenix in a way just like in normal java api we can
>>>> pass start row to filter data as follow
>>>> *//creating a scan object with start and stop row keys*
>>>> *Scan scan = new
>>>> Scan(Bytes.ToBytes("a.b.x|1"),Bytes.toBytes("a.b.x|2"); *
>>>>
>>>>
>>>>
>>>
>>
>>
>> --
>> Regards: HAFIZ MUJADID
>>
>
>


-- 
Regards: HAFIZ MUJADID

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