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Date: Tue, 5 Nov 2013 17:28:10 -0800
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 <CAH72Ak_fzwrcW4jcFYyiFqdkP88B2Hf86U-iGzKYgGxaU4=ZoA@mail.gmail.com>
Subject: Re: Column qualifiers with hierarchy and filters
From: Premal Shah <premal.j.shah@gmail.com>
To: user <user@hbase.apache.org>
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you can store the byte representation of the integer (fixed length) instead
of the integer (which will be stored as strings of variable length) and
will also be sorted.


On Tue, Nov 5, 2013 at 1:58 PM, Nasron Cheong
<nasron.cheong@kontagent.com>wrote:

> Yes, its limited in the sense that we have to precalculate the number of
> digits required so we don't run out, and if we overestimate, then our row
> keys end up taking up more space than we'd care to.
>
> We can probably live with this approach for now, but I wonder if there's a
> better way.
>
> - Nasron
>
>
> On Tue, Nov 5, 2013 at 12:28 PM, Jean-Marc Spaggiari <
> jean-marc@spaggiari.org> wrote:
>
> > Hi Nasron,
> >
> > Why are you saying that it's a limited way? Does it achieve your needs?
> >
> >
> > 2013/11/4 Nasron Cheong <nasron.cheong@kontagent.com>
> >
> > > An example query would be the following, say the column qualifier was
> of
> > > the form
> > >
> > > <bucket #>:<msg type>
> > >
> > > where <bucket #> should be an integer value, and msg type is a string.
> > E.g.
> > >
> > > 1:abc
> > > 1000:abc
> > > 2: abc
> > >
> > > would appear in the above sequence, which is out of order when doing
> > prefix
> > > filtering. Zero padding could fix this:
> > >
> > > 0001:abc
> > > 0002:abc
> > > 1000: abc
> > >
> > > But is a limited way of ensuring the sequence of CQ (column qualifiers)
> > is
> > > correct, in order for prefix filtering to work. Are there other
> options?
> > >
> > > - Nasron
> > >
> > >
> > > On Thu, Oct 31, 2013 at 9:19 PM, Nasron Cheong
> > > <nasron.cheong@kontagent.com>wrote:
> > >
> > > > Hi,
> > > >
> > > > I'm trying to determine the best way to serialize a sequence of
> > > > integers/strings that represent a hierarchy for a column qualifier,
> > which
> > > > would be compatible with the ColumnPrefixFilters, and
> > BinaryComparators.
> > > >
> > > > However, due to the lexicographical sorting, it's awkward to
> serialize
> > > the
> > > > sequence of values needed to get it to work.
> > > >
> > > > What are the typical solutions to this? Do people just zero pad
> > integers
> > > > to make sure they sort correctly? Or do I have to implement my own
> > > > QualifierFilter - which seems expensive since I'd be deserializing
> > every
> > > > byte array just to compare.
> > > >
> > > > Thanks
> > > >
> > > > - Nasron
> > > >
> > >
> >
>


-- 
Regards,
Premal Shah.

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