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From "M. BagherEsmaeily" <mbesmae...@gmail.com>
Subject Re: Limit number of columns in column family
Date Wed, 25 Sep 2013 07:15:29 GMT
Hi,
This is a good idea, but its other limitations make problem for my design.
Thank you.


On Tue, Sep 24, 2013 at 1:02 AM, Dave Latham <latham@davelink.net> wrote:

> What about having all columns in the column family use the same qualifier
> and then setting the max versions for that column family to limit it?
> http://hbase.apache.org/book.html#schema.versions
>
> It would only work if you didn't need to do updates to the cell without
> knowing its timestamp or having them count against the total number of
> cells to keep around.
>
>
> On Wed, Sep 18, 2013 at 11:23 PM, Jean-Marc Spaggiari <
> jean-marc@spaggiari.org> wrote:
>
> > Don't worry for the language ;)
> >
> > I don't think there is any mecanism today to limit the number of columns
> > into a column family.
> >
> > There might be multiple options but they will all have some drawback.
> >
> > On option is to have a daily mapreduce job looking at each row and doing
> > the cleanup. This can work if you don't have millions of huge columns
> > because you will have to keep track of all of them to see how many you
> have
> > and how many you need to remove...
> >
> > There might be some other options, like keep the index in the column name
> > so you know you need to remove all column with name < XXX where XXX is
> the
> > last index value minus the numbre of columns you can to keep.
> >
> > etc.
> >
> > JM
> >
> >
> > 2013/9/18 M. BagherEsmaeily <mbesmaeily@gmail.com>
> >
> > > any cell in the same row.
> > > Sorry because of my poor language!
> > >
> > >
> > > On Thu, Sep 19, 2013 at 9:28 AM, Jean-Marc Spaggiari <
> > > jean-marc@spaggiari.org> wrote:
> > >
> > > > Hi MBE,
> > > >
> > > > When you are saying "cells  with least timestamp being removed" you
> > mean
> > > > versions of the same cell? Or any cell in the same row/cf?
> > > >
> > > > JM
> > > >
> > > >
> > > > 2013/9/18 M. BagherEsmaeily <mbesmaeily@gmail.com>
> > > >
> > > > > Hi,
> > > > > I have a column family that I want the number of columns on it has
> a
> > > > > specific limit, and when this number becomes greater than the
> limit,
> > > > cells
> > > > > with least timestamp being removed, like TTL on count not time.
> > > > > Please guide me to find best optimized way.
> > > > >
> > > > > Thanks.
> > > > > MBE
> > > > >
> > > >
> > >
> >
>

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