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Posted to user@hbase.apache.org by Shixiaolong <sh...@huawei.com> on 2013/04/09 05:00:38 UTC

答复: Best way to query multiple sets of rows

Hi, Jean
   I guess Greame maybe asked whether Hbase can support parallel 
scan provided by client API, because currently, client API doesn't 
provide concurrent access if the range query crosses multi-regions?
  Now, if we want to support parallel scan, we have to use 
coprocessor to implement, whether it can be as built-in API, it
will be more friendly.

thanks
shixiaolong

-----邮件原件-----
发件人: Jean-Marc Spaggiari [mailto:jean-marc@spaggiari.org] 
发送时间: 2013年4月9日 2:28
收件人: user@hbase.apache.org
主题: Re: Best way to query multiple sets of rows

Hi Greame,

The scans are the right way to do that.

They will give you back all the data you need, chunck by chunk. Then
yoiu have to iterate over the data to do what you want with it.

What was your expectation? I'm not sure I'm getting your "so that i
dont have to issue sequential Scans".

jM

2013/4/8 Graeme Wallace <gr...@farecompare.com>:
> Hi,
>
> Maybe there is an obvious way but i'm not seeing it.
>
> I have a need to query HBase for multiple chunks of data, that is something
> equivalent to
>
> select columns
> from table
> where rowid between A and B
> or rowid between C and D
> or rowid between E and F
> etc.
>
> in SQL.
>
> Whats the best way to go about doing this so that i dont have to issue
> sequential Scans ?
>
> --
> Graeme Wallace
> CTO
> FareCompare.com
> O: 972 588 1414
> M: 214 681 9018