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From "Jonathan Gray" <jl...@streamy.com>
Subject RE: Integer key range scan
Date Tue, 16 Dec 2008 22:32:29 GMT
intToBytes is really just a "cast" to bytes, allowing you to store the
actual binary value of the integer.  It would be in increasing numerical
order.

This is an example of the oddity that is Java...

Great move by using big-endian in the virtual machine, but if you want to
actually access the binary the JVM is using for an integer you have to write
your own function that uses bitwise operations to extract the value into a
byte[].

Anyways, the answer is Yes.

JG

> -----Original Message-----
> From: clint.a.m@gmail.com [mailto:clint.a.m@gmail.com] On Behalf Of
> Clint Morgan
> Sent: Tuesday, December 16, 2008 2:13 PM
> To: hbase-user@hadoop.apache.org
> Subject: Re: Integer key range scan
> 
> Does intToBytes preserve ordering? IE is the leicographic ordering of
> the
> resulting byte [] the same as the ordering of the original ints?
> 
> I think Edward needs that for his scan to work...
> 
> -clint
> 
> On Tue, Dec 16, 2008 at 1:25 PM, Jonathan Gray <jlist@streamy.com>
> wrote:
> 
> > I believe there are intToBytes/bytesToInt functions in Bytes.java.
> Rather
> > than padding and storing as strings, you can just store as binary
> numbers.
> >  If you can't find those functions I can send you one of our helper
> classes
> > that deals with binary data easily.
> >
> > Though this does make things a bit less pretty in web ui/shell it's
> far
> > more efficient.
> >
> > JG
> >
> > > -----Original Message-----
> > > From: edward@udanax.org [mailto:edward@udanax.org] On Behalf Of
> Edward
> > > J. Yoon
> > > Sent: Tuesday, December 16, 2008 9:39 AM
> > > To: hbase-user@hadoop.apache.org
> > > Subject: Re: Integer key range scan
> > >
> > > Oh Yes, Thanks for tip J-D.
> > >
> > > On Wed, Dec 17, 2008 at 2:27 AM, Jean-Daniel Cryans
> > > <jdcryans@apache.org> wrote:
> > > > Yes, then you would scan with startrow = 0000000035 and stoprow =
> > > 0000000236
> > > > if this is really what you want to do.
> > > >
> > > > J-D
> > > >
> > > > On Tue, Dec 16, 2008 at 12:25 PM, Edward J. Yoon
> > > <edwardyoon@apache.org>wrote:
> > > >
> > > >> Like this? 0000000035 ~ 0000000235
> > > >>
> > > >> On Wed, Dec 17, 2008 at 2:21 AM, Jean-Daniel Cryans
> > > <jdcryans@apache.org>
> > > >> wrote:
> > > >> > You can left pad with zeroes then use the scanning facility
> for
> > > faster
> > > >> > retrieval.
> > > >> >
> > > >> > J-D
> > > >> >
> > > >> > On Tue, Dec 16, 2008 at 12:18 PM, Edward J. Yoon
> > > <edwardyoon@apache.org
> > > >> >wrote:
> > > >> >
> > > >> >> I would use integer key and extract data from range scans.
> But,
> > > hbase
> > > >> >> row/column is alphabetically sorted.
> > > >> >>
> > > >> >> So, I wrote like below:
> > > >> >>
> > > >> >> for (int i = 35; i <= 235; i++) {
> > > >> >>  table.getRow(i, columns[]);
> > > >> >> }
> > > >> >>
> > > >> >> It seems, causes too many requests over hbase.
> > > >> >> Any suggestion?
> > > >> >>
> > > >> >> --
> > > >> >> Best Regards, Edward J. Yoon @ NHN, corp.
> > > >> >> edwardyoon@apache.org
> > > >> >> http://blog.udanax.org
> > > >> >>
> > > >> >
> > > >>
> > > >>
> > > >>
> > > >> --
> > > >> Best Regards, Edward J. Yoon @ NHN, corp.
> > > >> edwardyoon@apache.org
> > > >> http://blog.udanax.org
> > > >>
> > > >
> > >
> > >
> > >
> > > --
> > > Best Regards, Edward J. Yoon @ NHN, corp.
> > > edwardyoon@apache.org
> > > http://blog.udanax.org
> >
> >


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