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From ashish singhi <ashish.sin...@huawei.com>
Subject RE: Scan with SingleColumnValueFilterfilter giving wrong output
Date Fri, 04 Apr 2014 10:20:05 GMT
Hi Ram.

Thanks for your time and explanation.
I tried by setting true to SingleColumnValueFilter.setFilterIfMissing as you mentioned.

It worked for column value 'value2' in output I got only row2 with col1. 
But for column value 'value1' also I am getting one row i.e., row1 with col1. As you said
" In your first result row6 should not be the result (strictly if you want only value1 with
col1). You can see that it has col3 in the result."

But I want is to find all the columns in the table having mentioned column value. Can someone
please tell me how to get it ?

-----Original Message-----
From: ramkrishna vasudevan [mailto:ramkrishna.s.vasudevan@gmail.com] 
Sent: 04 April 2014 15:20
To: dev@hbase.apache.org
Subject: Re: Scan with SingleColumnValueFilterfilter giving wrong output

Hi Ashish

I think the behaviour is fine.  There is a property called filterIfMissing in Single Columnvalue
filter.  If you don't need a row which does not have the given column and value in your query,
then you should set that to true.
See SingleColumnValueFilter.setFilterIfMissing.
In your first result row6 should not be the result (strictly if you want only value1 with
col1). You can see that it has col3 in the result.

In your second result too row6 falls under the same category.
If a row has more than one cell and if we have found the matching cell, the following cells
of that row will also be included in the result.  I hope the same behavior is there in 0.94.11
also. (should be).

Regards
Ram



On Fri, Apr 4, 2014 at 2:37 PM, ashish singhi <ashish.singhi@huawei.com>wrote:

> Hi all.
>
> I am using,
> HBase Version - 0.94.11
> Hadoop Version - 2.1.0
>
> I am trying to get columns having the specified value. So for that I 
> am using org.apache.hadoop.hbase.filter.SingleColumnValueFilter class.
> But when I try to scan table to find columns with column value 
> 'value2', I think I am not getting proper output.
>
> Can someone please tell me where I am wrong ?
>
> I have a simple hbase table with records.
> hbase(main):014:0> scan 'testTable'
> ROW                                                  COLUMN+CELL
> row1
>  column=colFammily1:col1, timestamp=1396586048561, value=value1
> row2
>  column=colFammily1:col1, timestamp=1396586054526, value=value2
> row2
>  column=colFammily1:col2, timestamp=1396585985022, value=testValue
> row3
>  column=colFammily1:col1, timestamp=1396586060989, value=value3
> row4
>  column=colFammily1:col1, timestamp=1396586066037, value=value4
> row5
>  column=colFammily1:col1, timestamp=1396586071842, value=value5
> row6
>  column=colFammily1:col3, timestamp=1396590405939, value=value1
> 6 row(s) in 0.0320 seconds
>
> First: When I executed scan command with column value 'value1' I got 
> the proper output.
> hbase(main):023:0> scan 'testTable', {FILTER => 
> org.apache.hadoop.hbase.filter.SingleColumnValueFilter.new(org.apache.
> hadoop.hbase.util.Bytes.toBytes('colFammily1'),org.apache.hadoop.hbase
> .util.Bytes.toBytes('col1'), 
> org.apache.hadoop.hbase.filter.CompareFilter::CompareOp.valueOf('EQUAL'),org.apache.hadoop.hbase.util.Bytes.toBytes('value1'))}
> ROW                                                  COLUMN+CELL
> row1
>  column=colFammily1:col1, timestamp=1396586048561, value=value1
> row6
>  column=colFammily1:col3, timestamp=1396590405939, value=value1
> 2 row(s) in 0.0160 seconds
>
> Second: When I tried same command with column value 'value2' the 
> output seems to be incorrect.
> hbase(main):025:0> scan 'testTable', {FILTER => 
> org.apache.hadoop.hbase.filter.SingleColumnValueFilter.new(org.apache.
> hadoop.hbase.util.Bytes.toBytes('colFammily1'),org.apache.hadoop.hbase
> .util.Bytes.toBytes('col1'), 
> org.apache.hadoop.hbase.filter.CompareFilter::CompareOp.valueOf('EQUAL'),org.apache.hadoop.hbase.util.Bytes.toBytes('value2'))}
> ROW                                                  COLUMN+CELL
> row2
>  column=colFammily1:col1, timestamp=1396586054526, value=value2
> row2
>  column=colFammily1:col2, timestamp=1396585985022, value=testValue
> row6
>  column=colFammily1:col3, timestamp=1396590405939, value=value1
> 2 row(s) in 0.0100 seconds
>
> I am not able to understand why I am getting row2 with col2 and row6 
> in the output where in their column values are not 'value2'.
>
> Regards,
> Ashish
>

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