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HBase >> mail # user >> Problem deleting neighboors with timestamp=0


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Chris Larsen 2012-11-18, 20:14
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ramkrishna vasudevan 2012-11-19, 04:31
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RE: Problem deleting neighboors with timestamp=0
> So you mean that you have explicitly set the timestamp to 0 for the column
which you did not want to delete?

Yes, my code was setting the timestamp explicitly to 0. I fixed that bug in
my code (since I do want a valid timestamp) but I was wondering if a
timestamp of 0 is "legal" and if it isn't, maybe HBase should kick back
errors if someone tries it.

-----Original Message-----
From: ramkrishna vasudevan [mailto:[EMAIL PROTECTED]]
Sent: Sunday, November 18, 2012 11:31 PM
To: [EMAIL PROTECTED]
Subject: Re: Problem deleting neighboors with timestamp=0

Hi Chris

So you mean that you have explicitly set the timestamp to 0 for the column
which you did not want to delete?

Regards
Ram

On Mon, Nov 19, 2012 at 1:44 AM, Chris Larsen
<[EMAIL PROTECTED]>wrote:

> Hello, I was going nuts over an issue where I would try to delete a
> single column but a neighboring column (sorted by the column names in
> bytes) was also being deleted because, I found out, the timestamp for
> the neighbor was set to 0. Here are some of the columns in the row
> (taken from the shell
> utility)
>
>
>
> hbase(main):002:0> get 'mytable',
> "\x00\x01\xAA\x50\x8E\xC4\x20\x00\x00\x01\x00\x00\xAC"
>
> COLUMN                                  CELL
>
> t:\x00\x17                             timestamp=1351533601998,
> value=\x00\x00\x00\x00O\xB2\xDC[
>
> t:\x00\x17\x03\xD7\x...(long name)     timestamp=0, value=\x00\x00\x...
> lots
> of binary data....
>
> t:\x03\xD7                             timestamp=1351533661458,
> value=\x00\x00\x00\x00O\xB9\xD1\xE5
>
> t:\x07\x97                             timestamp=1351533721758,
> value=\x00\x00\x00\x00O\xBC#\xD0
>
> t:\x0BW                                timestamp=1351533781738,
> value=\x00\x00\x00\x00O\xBD\xB93
>
>
>
> I wanted to delete the column "t:\x00\x17" but every time I did, the
> column "t:\x00\x17\x03\xD7\x..." would also be deleted so that I'd wind up
with:
>
>
>
> hbase(main):005:0> get 'mytable',
> "\x00\x01\xAA\x50\x8E\xC4\x20\x00\x00\x01\x00\x00\xAC"
>
> COLUMN                                  CELL
>
> t:\x03\xD7                             timestamp=1351533661458,
> value=\x00\x00\x00\x00O\xB9\xD1\xE5
>
> t:\x07\x97                             timestamp=1351533721758,
> value=\x00\x00\x00\x00O\xBC#\xD0
>
> t:\x0BW                                timestamp=1351533781738,
> value=\x00\x00\x00\x00O\xBD\xB93
>
>
>
> My JAVA code looked like this:
>
>
>
> HTableInterface table = factory.createHTableInterface(config,
> "mytable".getBytes());
>
> Delete delete = new Delete(HexToBytes("0001AA508EC4200000010000AC"));
>
> delete.deleteColumn("t".getBytes(), new byte[] { (byte) 0x00, (byte)
> 0x17 });
>
> table.delete(delete);
>
>
>
> as I was typing this out, I noticed that the column I didn't want to
> delete had a timestamp of 0. I put the column back with a valid
> timestamp and tried deleting the original column, and it worked
> properly. I fixed my code to always provide a positive timestamp, but
> my question is, are timestamps set to 0 valid for storing data in
> HBase? And if so, then this may be a bug that needs addressing.
> Thanks!
>
>
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anil gupta 2012-11-19, 07:44
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Chris Larsen 2012-11-19, 16:24
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ramkrishna vasudevan 2012-11-19, 18:14
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Chris Larsen 2012-11-19, 20:40
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Chris Larsen 2012-11-19, 21:25