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From Matthew Dennis <mden...@riptano.com>
Subject Re: Re: Sorting in Cassandra
Date Wed, 06 Oct 2010 20:34:11 GMT
The SCs are stored on disk in the order defined by the compareWith setting
so if you want them back in a different order either someone is sorting them
(C*, which doesn't sort them right now, or the client; which doesn't make
much of a difference, it's just moving the load around) or you're
denormalizing/duplicating the data in another SCF so it's stored in the
order you want and can be read from disk in that order.

On Wed, Oct 6, 2010 at 2:58 AM, cbertu81@libero.it <cbertu81@libero.it>wrote:

> Aaron,
>
> first of all thanks for your time.
>
>
> *1. You cannot return just the super columns, you have to get their sub
> columns as well. The returned data is ordered, please provide and example of
> where it is not. *
>
>
> I don't know what I did before but now I checked and data are sorted as I
> expected them to be :-o.
> I know I can't get a SC without their sub columns and this is ok.
>
> *2. Pull back the entire row and filter/sort the columns client side. It's
> not possible to return columns of the same name from different super columns
> (I think that's what you are asking). Let me know if you think you have too
> much data per row to do that. *
>
> Probably I explained myself wrong. What I want is to get the entire ROW
> back but already ordered on the base of a specific column key and not on the
> base of the SCKey ... example
>
> UID (ROW) {
>     Company0 { name: zaz, address: street x, phone: 123, other cols }
>     Company1 { name: abacus, address: street y, phone: 234, other cols }
>     Company2 { name: more, address: street x, phone: 345, other cols }
> }
>
> What I want is to get all the data back from cassandra sorted by the name
> of the company, and not of the SC  ...
>
> UID (ROW) {
>     Company1 { name: abacus, address: street y, phone: 234, other cols }
>     Company2 { name: more, address: street x, phone: 345, other cols }
>     Company0 { name: zaz, address: street x, phone: 123, other cols }
> }
>
> As far as I know Cassandra I don't think it's possible since I cannot be
> sure that each SC contains the specific Column (name), right?
> Is the only way to sort them on client-side?
>
> Best Regards
>
>

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