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From Alex Baranau <alex.barano...@gmail.com>
Subject Re: Column Value Reference Timestamp Filter
Date Mon, 20 Aug 2012 20:47:05 GMT
Hi,

So, you have row with key rowKeyA and column col1. And it contains two
values value1 and value2 at timestamp1 and timestamp2 respectively, where
timestamp1 is most recent. And you want to fetch "most recent but one"
values in all columns when doing the scan. I.e. you don't know the
timestamp1 or timestamp2 exactly you just need to fetch the value which was
placed before the most recent one. Is that correct?

Don't think there's some filter that would allow you to do so
"out-of-the-box". You should probably be able to write such filter and use
scan.setMaxVersions(2). Not sure if keyvalues are fed into filter ordered
by their timestamp..

How about returning 2 most recent values to the client and filtering on the
client-side? Why this doesn't work in your case? (large values in columns
in size or?).

Alex Baranau
------
Sematext :: http://blog.sematext.com/ :: Hadoop - HBase - ElasticSearch -
Solr

On Mon, Aug 20, 2012 at 2:57 PM, Jerry Lam <chilinglam@gmail.com> wrote:

> Hi HBase community:
>
> I have a requirement in which I need to query a row based on the timestamp
> stored in the value of a column of a row. For example.
>
> (rowkeyA of col1) -> (value) at timestamp = t1, (value) stores t2. Result
> should return all columns of rowkeyA at timestamp = t2.
>
> Note that t1 > t2 ALWAYS.
>
> Can this sound like something that can be done using Filter? If yes, can it
> be done using the existing filters in HBase without customization?
>
> Best Regards,
>
> Jerry
>

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