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From Erik Holstad <erikhols...@gmail.com>
Subject Re: Questions about HBase
Date Mon, 01 Mar 2010 22:33:13 GMT
On Mon, Mar 1, 2010 at 2:16 PM, Ryan Rawson <ryanobjc@gmail.com> wrote:

> Hi,
>
> 1.  We use in-memory indexes to get fast random reads.  Our index
> tells us to read block X of a file only retrieving a small amount of
> the file to satisfy the user's read.
>
> 2.  The row locking is not global - for each row there can only be 1
> thread doing a put at a time.  This serializes all puts to a single
> row. It is NOT global.
>

So, this is me not understanding the difference between global locking and
waiting in a line until the tasks ahead of you are done :)

>
> On Mon, Mar 1, 2010 at 12:36 PM, William Kang <weliam.cloud@gmail.com>
> wrote:
> > Hi guys,
> > I am new to HBase and have several questions. Would anybody kindly answer
> > some of them?
> >
> > 1. Why HBase could provide a low-latency random access to files compared
> to
> > HDFS?
> >
> > 2. By default, Only a single row at a time may be locked. Is it a single
> > client who can only lock one or is it globally can only lock one?  If
> this
> > is the case, by default, will the performance be really bad?
> >
> > Many thanks!
> >
> >
> > William
> >
>



-- 
Regards Erik

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