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Posted to user@hbase.apache.org by 冯宏华 <fe...@xiaomi.com> on 2013/06/12 10:51:30 UTC
答复: Scanning not show the correct value of latest version
hi, Kyle
This is NOT a bug. There are three types of delete: Delete, DeleteColumn, DeleteFamily; Delete is actually DeleteCell which can only mask(delete) a cell with exactly the SAME timestamp, in your below case, "* Row1 column=cf:c2, timestamp=1370935373545, type=Delete" is a Delete (DeleteCell) so it can only mask(delete) " Row1 column=cf:c2, timestamp=1370935373545, value=kk" since they have the same timestamps, but can't mask(delete) "Row1 column=cf:c2, timestamp=1370935357741, value=h *" since they have different timestamps
DeleteColumn can do what you expect: it can mask(delete) cells under the column with timestamps less or equal to the timestamp of the DeleteColumn
--Honghua
________________________________________
发件人: Kyle Lin [kylelin2000@gmail.com]
发送时间: 2013年6月11日 16:58
收件人: user@hbase.apache.org
主题: Scanning not show the correct value of latest version
Hey Guys
After I modifying a cell many times with delete action, The result of
scan is not correct.
I Expect the value of "Row1 cf:c2" is null because I've delete the
cell(The line with blue color below). But I actually got "h"(The line with
green color below).
Is this a hbase bug? Or my operating fault?
hbase(main):007:0> scan 'table42', {RAW => true, VERSIONS => 3}
ROW
COLUMN+CELL
Row1 column=cf:c1, timestamp=1370935357679,
value=e
* Row1 column=cf:c2,
timestamp=1370935373545, type=Delete
Row1 column=cf:c2, timestamp=1370935373545,
value=kk
Row1 column=cf:c2, timestamp=1370935357741,
value=h *
Row2 column=cf:c1, timestamp=1370935357804,
value=p
Row2 column=cf:c2, timestamp=1370935380939,
value=pp
Row2 column=cf:c2, timestamp=1370935373582,
value=jj
Row2 column=cf:c2, timestamp=1370935357774,
value=d
2 row(s) in 0.0220 seconds
hbase(main):008:0> scan 'table42'
ROW
COLUMN+CELL
Row1 column=cf:c1, timestamp=1370935357679,
value=e
* Row1 column=cf:c2,
timestamp=1370935357741, value=h *
Row2 column=cf:c1, timestamp=1370935357804,
value=p
Row2 column=cf:c2, timestamp=1370935380939,
value=pp
2 row(s) in 0.0200 seconds
*P.S. My HBase Version is 0.94.6*
Kyle
答复: 答复: Scanning not show the correct value of latest version
Posted by 冯宏华 <fe...@xiaomi.com>.
My pleasure :-)
--Honghua
________________________________________
发件人: Kyle Lin [kylelin2000@gmail.com]
发送时间: 2013年6月13日 10:41
收件人: user@hbase.apache.org
主题: Re: 答复: Scanning not show the correct value of latest version
Hello Hong Hua
I've do some experiments and really got the rule of deletion. Thanks for
your explanation.
2013/6/12 冯宏华 <fe...@xiaomi.com>
> hi, Kyle
>
> This is NOT a bug. There are three types of delete: Delete, DeleteColumn,
> DeleteFamily; Delete is actually DeleteCell which can only mask(delete) a
> cell with exactly the SAME timestamp, in your below case, "* Row1
> column=cf:c2, timestamp=1370935373545, type=Delete" is
> a Delete (DeleteCell) so it can only mask(delete) " Row1 column=cf:c2,
> timestamp=1370935373545, value=kk" since they have the same timestamps, but
> can't mask(delete) "Row1 column=cf:c2, timestamp=1370935357741, value=h
> *" since they have different timestamps
>
> DeleteColumn can do what you expect: it can mask(delete) cells under the
> column with timestamps less or equal to the timestamp of the DeleteColumn
>
> --Honghua
>
> ________________________________________
> 发件人: Kyle Lin [kylelin2000@gmail.com]
> 发送时间: 2013年6月11日 16:58
> 收件人: user@hbase.apache.org
> 主题: Scanning not show the correct value of latest version
>
> Hey Guys
>
> After I modifying a cell many times with delete action, The result of
> scan is not correct.
>
> I Expect the value of "Row1 cf:c2" is null because I've delete the
> cell(The line with blue color below). But I actually got "h"(The line with
> green color below).
>
> Is this a hbase bug? Or my operating fault?
>
> hbase(main):007:0> scan 'table42', {RAW => true, VERSIONS => 3}
> ROW
> COLUMN+CELL
>
> Row1 column=cf:c1, timestamp=1370935357679,
> value=e
> * Row1 column=cf:c2,
> timestamp=1370935373545, type=Delete
>
> Row1 column=cf:c2, timestamp=1370935373545,
> value=kk
> Row1 column=cf:c2, timestamp=1370935357741,
> value=h *
> Row2 column=cf:c1, timestamp=1370935357804,
> value=p
> Row2 column=cf:c2, timestamp=1370935380939,
> value=pp
> Row2 column=cf:c2, timestamp=1370935373582,
> value=jj
> Row2 column=cf:c2, timestamp=1370935357774,
> value=d
> 2 row(s) in 0.0220 seconds
>
> hbase(main):008:0> scan 'table42'
> ROW
> COLUMN+CELL
>
> Row1 column=cf:c1, timestamp=1370935357679,
> value=e
> * Row1 column=cf:c2,
> timestamp=1370935357741, value=h *
>
> Row2 column=cf:c1, timestamp=1370935357804,
> value=p
> Row2 column=cf:c2, timestamp=1370935380939,
> value=pp
> 2 row(s) in 0.0200 seconds
>
>
> *P.S. My HBase Version is 0.94.6*
>
>
> Kyle
>
Re: 答复: Scanning not show the correct value of latest version
Posted by Kyle Lin <ky...@gmail.com>.
Hello Hong Hua
I've do some experiments and really got the rule of deletion. Thanks for
your explanation.
2013/6/12 冯宏华 <fe...@xiaomi.com>
> hi, Kyle
>
> This is NOT a bug. There are three types of delete: Delete, DeleteColumn,
> DeleteFamily; Delete is actually DeleteCell which can only mask(delete) a
> cell with exactly the SAME timestamp, in your below case, "* Row1
> column=cf:c2, timestamp=1370935373545, type=Delete" is
> a Delete (DeleteCell) so it can only mask(delete) " Row1 column=cf:c2,
> timestamp=1370935373545, value=kk" since they have the same timestamps, but
> can't mask(delete) "Row1 column=cf:c2, timestamp=1370935357741, value=h
> *" since they have different timestamps
>
> DeleteColumn can do what you expect: it can mask(delete) cells under the
> column with timestamps less or equal to the timestamp of the DeleteColumn
>
> --Honghua
>
> ________________________________________
> 发件人: Kyle Lin [kylelin2000@gmail.com]
> 发送时间: 2013年6月11日 16:58
> 收件人: user@hbase.apache.org
> 主题: Scanning not show the correct value of latest version
>
> Hey Guys
>
> After I modifying a cell many times with delete action, The result of
> scan is not correct.
>
> I Expect the value of "Row1 cf:c2" is null because I've delete the
> cell(The line with blue color below). But I actually got "h"(The line with
> green color below).
>
> Is this a hbase bug? Or my operating fault?
>
> hbase(main):007:0> scan 'table42', {RAW => true, VERSIONS => 3}
> ROW
> COLUMN+CELL
>
> Row1 column=cf:c1, timestamp=1370935357679,
> value=e
> * Row1 column=cf:c2,
> timestamp=1370935373545, type=Delete
>
> Row1 column=cf:c2, timestamp=1370935373545,
> value=kk
> Row1 column=cf:c2, timestamp=1370935357741,
> value=h *
> Row2 column=cf:c1, timestamp=1370935357804,
> value=p
> Row2 column=cf:c2, timestamp=1370935380939,
> value=pp
> Row2 column=cf:c2, timestamp=1370935373582,
> value=jj
> Row2 column=cf:c2, timestamp=1370935357774,
> value=d
> 2 row(s) in 0.0220 seconds
>
> hbase(main):008:0> scan 'table42'
> ROW
> COLUMN+CELL
>
> Row1 column=cf:c1, timestamp=1370935357679,
> value=e
> * Row1 column=cf:c2,
> timestamp=1370935357741, value=h *
>
> Row2 column=cf:c1, timestamp=1370935357804,
> value=p
> Row2 column=cf:c2, timestamp=1370935380939,
> value=pp
> 2 row(s) in 0.0200 seconds
>
>
> *P.S. My HBase Version is 0.94.6*
>
>
> Kyle
>