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From Erik Holstad <erikhols...@gmail.com>
Subject Re: Using column plus value or only column?
Date Tue, 02 Feb 2010 23:02:39 GMT
@Nathan
So what I'm planning to do is to store multiple sort orders for the same
data, where they all use the
same data table just fetches it in different orders, so to say. I want to be
able to rad the different sort
orders from the front and from the back to get both regular and reverse sort
order.

With your approach using super columns you would need to replicate all data,
right?

And if I understand
http://issues.apache.org/jira/browse/CASSANDRA-598correctly you would
need to
read the whole thing before you can limit the results handed back to you.

In regards to the two calls get_slice and get_range_slice, the way I
understand it is that you hand
the second one an optional start and stop key plus a limit, to get a range
of keys/rows. I was planning
to use this call together with the OPP, but are thinking about not using it
since there is no way to do
an inverse scan, right?

Thanks a lot
Erik


On Tue, Feb 2, 2010 at 2:39 PM, Jesse McConnell
<jesse.mcconnell@gmail.com>wrote:

> infinite is a bit of a bold claim....
>
> by my understanding you are bound by the memory of the jvm as all of
> the content of a key/row currently needs to fit in memory for
> compaction, which includes columns and supercolumns for given key/row.
>
> if you are going to run into those scenarios then some sort of
> sharding on the keys is required, afaict
>
> cheers,
> jesse
>
> --
> jesse mcconnell
> jesse.mcconnell@gmail.com
>
>
>
> On Tue, Feb 2, 2010 at 16:30, Nathan McCall <nate@vervewireless.com>
> wrote:
> > Erik,
> > Sure, you could and depending on the workload, that might be quite
> > efficient for small pieces of data. However, this also sounds like
> > something that might be better addressed with the addition of a
> > SuperColumn on "Sorts" and getting rid of "Data" altogether:
> >
> > Sorts : {
> >   sort_row_1 : {
> >        sortKey1 : { col1:val1, col2:val2 },
> >        sortKey2 : { col1:val3, col2:val4 }
> >   }
> > }
> >
> > You can have an infinite number of SuperColumns for a key, but make
> > sure you understand get_slice vs. get_range_slice before you commit to
> > a design. Hopefully I understood your example correctly, if not, do
> > you have anything more concrete?
> >
> > Cheers,
> > -Nate
> >
> >
> > On Tue, Feb 2, 2010 at 12:00 PM, Erik Holstad <erikholstad@gmail.com>
> wrote:
> >> Thanks Nate for the example.
> >>
> >> I was thinking more a long the lines of something like:
> >>
> >> If you have a family
> >>
> >> Data : {
> >>   row1 : {
> >>     col1:val1,
> >>   row2 : {
> >>     col1:val2,
> >>     ...
> >>   }
> >> }
> >>
> >>
> >> Using
> >> Sorts : {
> >>   sort_row : {
> >>     sortKey1_datarow1: [],
> >>     sortKey2_datarow2: []
> >>   }
> >> }
> >>
> >> Instead of
> >> Sorts : {
> >>   sort_row : {
> >>     sortKey1: datarow1,
> >>     sortKey2: datarow2
> >>   }
> >> }
> >>
> >> If that makes any sense?
> >>
> >> --
> >> Regards Erik
> >>
> >
>



-- 
Regards Erik

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