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From "Niels Basjes (JIRA)" <j...@apache.org>
Subject [jira] [Updated] (HBASE-11990) Make setting the start and stop row for a specific prefix easier
Date Tue, 16 Sep 2014 09:48:33 GMT

     [ https://issues.apache.org/jira/browse/HBASE-11990?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]

Niels Basjes updated HBASE-11990:
---------------------------------
    Description: 
If you want to set a scan from your application to scan for a specific row prefix this is
actually quite hard.
As described in several places you can set the startRow to the prefix; yet the stopRow should
be set to the prefix '+1'
If the prefix 'ASCII' put into a byte[] then this is easy because you can simply increment
the last byte of the array. 
But if your application uses real binary rowids you may run into the scenario that your prefix
is something like 
{code}{ 0x12, 0x23, 0xFF, 0xFF }{code} Then the increment should be {code}{ 0x12, 0x24, 0x00,
0x00 }{code}

I have prepared a proposed patch that makes setting these values correctly a lot easier.

  was:
If you want to set a scan from your application to scan for a specific row prefix this is
actually quite hard.
As described in several places you can set the startRow to the prefix; yet the stopRow should
be set to the prefix '+1'
If the prefix 'ASCII' put into a byte[] then this is easy because you can simply increment
the last byte of the array. 
But if your application uses real binary rowids you may run into the scenario that your prefix
is something like { 0x12, 0x23, 0xFF, 0xFF }. Then the increment should be { 0x12, 0x24, 0x00,
0x00 }.

I have prepared a proposed patch that makes setting these values correctly a lot easier.


> Make setting the start and stop row for a specific prefix easier
> ----------------------------------------------------------------
>
>                 Key: HBASE-11990
>                 URL: https://issues.apache.org/jira/browse/HBASE-11990
>             Project: HBase
>          Issue Type: New Feature
>          Components: Client
>            Reporter: Niels Basjes
>         Attachments: HBASE-11990-20140916.patch
>
>
> If you want to set a scan from your application to scan for a specific row prefix this
is actually quite hard.
> As described in several places you can set the startRow to the prefix; yet the stopRow
should be set to the prefix '+1'
> If the prefix 'ASCII' put into a byte[] then this is easy because you can simply increment
the last byte of the array. 
> But if your application uses real binary rowids you may run into the scenario that your
prefix is something like 
> {code}{ 0x12, 0x23, 0xFF, 0xFF }{code} Then the increment should be {code}{ 0x12, 0x24,
0x00, 0x00 }{code}
> I have prepared a proposed patch that makes setting these values correctly a lot easier.



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