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From Alain RODRIGUEZ <arodr...@gmail.com>
Subject Re: range queries
Date Wed, 27 Feb 2013 13:25:51 GMT
"What am I doing wrong here?"

You are probably using a RandomPartitioner (or Murmur3Partitioner) which
randomize keys to avoid hot spots.

Basically, you just can't use range query because 'nlxxxxxxxxxx' is stored
as md5('nlxxxxxxxxxx'). You should better modify your model to use column
slice, which are ordered.

An other solution, which is not recommended at all because it leads to hot
spots, is to use an OrderedPreservingPartitioner. But once again, I think
you shouldn't do it.

I have no time to go deeper in my explanation but with what I already told
you, you should be able to find out by yourself more details if needed.

Alain


2013/2/27 Sloot, Hans-Peter <hans-peter.sloot@atos.net>

> Hello,
>
> I have what is perhaps a silly question.
>
> Column family other2 which has a varchar as primary key and a uuid column.
> I  have inserted 2000 rows
>
> All rows keys start with 'nl' followed by other characters.
>
> To my surprise when I do  : select count(*) from other2 where key > 'z';
>
> It shows :
>
>  count
> -------
>   1947
>
> All rows start with a character smaller than 1.
>
> But it becomes even more strange:
>
> cqlsh:demo> select count(*) from other2 where key > 'zz';
>  count
> -------
>   1415
>
> cqlsh:demo> select count(*) from other2 where key > 'zzz';
>  count
> -------
>   1820  < -- now the row count has even increased.
>
> What am I doing wrong here?
>
> Regards
>
>
>
>
>
>
>
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