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HBase, mail # dev - disk seek in range search


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Weishung Chung 2011-03-26, 15:57
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Jean-Daniel Cryans 2011-03-28, 16:23
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Re: disk seek in range search
Weishung Chung 2011-03-28, 16:52
Thank you Jean for the reading materials, I've been reading the source codes
and searching on the internet and have a very vague idea how everything is
working. Give me a few more days(don't want to embarrass myself), I will
check back with you guys to see if my understanding is correct or not :D

Have a good day, thanks again :)

On Mon, Mar 28, 2011 at 11:23 AM, Jean-Daniel Cryans <[EMAIL PROTECTED]>wrote:

> I think you are asking for a bit too much :)
>
> Let's do it the other way, show us what you think are the answers to
> your questions based on currently available documentation and by
> looking at the source code, then I'm pretty sure someone will be happy
> to verify it.
>
> Start by looking at the bigtable paper, then use Lars George's blog posts
> like:
>
> http://www.larsgeorge.com/2009/10/hbase-architecture-101-storage.html
>
> http://www.larsgeorge.com/2010/01/hbase-architecture-101-write-ahead-log.html
> http://www.larsgeorge.com/2010/05/hbase-file-locality-in-hdfs.html
>
> And then try diving into the code.
>
> Good luck!
>
> J-D
>
> On Sat, Mar 26, 2011 at 8:57 AM, Weishung Chung <[EMAIL PROTECTED]>
> wrote:
> > Dear fellow HBase developers,
> >
> > Could someone educate me and let me know how to figure out the number of
> > disk seeks involved in a range search (startRow to endRow specified in
> > Scan). Also, could anyone give me the details of all the steps involved
> once
> > the Scan for range retrieval is called? I know somehow it needs to figure
> > out the regionservers used in hosting the rows but I still don't have a
> > clear understanding the whole steps involved :( :( Also, there is a data
> > index block in HFile, I was wondering how the index block is utilized in
> > figuring out the location of all the rows.
> >
> > Thank you so much for satisfying my curiosity :)
> >
> > Have a good weekend and enjoy :)
> >
> > Wei Shung
> >
>
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Jean-Daniel Cryans 2011-03-28, 17:00