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From Aaron Turner <synfina...@gmail.com>
Subject Re: quick question about data layout on disk
Date Sat, 11 Aug 2012 18:03:57 GMT
So how does that work?  An sstable is for a single CF, but it can and
likely will have multiple rows.  There is no read to write and as I
understand it, writes are append operations.

So if you have an sstable with say 26 different rows (A-Z) already in
it with a bunch of columns and you add a new column to row J, how does
Cassandra store the column/value pair on disk in a way to refer to row
J without re-writing the row key or some representation of it?

Thanks,
Aaron

On Fri, Aug 10, 2012 at 7:53 PM, Terje Marthinussen
<tmarthinussen@gmail.com> wrote:
> Rowkey is stored only once in any sstable file.
>
> That is, in the spesial case where you get sstable file per column/value, you are correct,
but normally, I guess most of us are storing more per key.
>
> Regards,
> Terje
>
> On 11 Aug 2012, at 10:34, Aaron Turner <synfinatic@gmail.com> wrote:
>
>> Curious, but does cassandra store the rowkey along with every
>> column/value pair on disk (pre-compaction) like Hbase does?  If so
>> (which makes the most sense), I assume that's something that is
>> optimized during compaction?
>>
>>
>> --
>> Aaron Turner
>> http://synfin.net/         Twitter: @synfinatic
>> http://tcpreplay.synfin.net/ - Pcap editing and replay tools for Unix & Windows
>> Those who would give up essential Liberty, to purchase a little temporary
>> Safety, deserve neither Liberty nor Safety.
>>    -- Benjamin Franklin
>> "carpe diem quam minimum credula postero"



-- 
Aaron Turner
http://synfin.net/         Twitter: @synfinatic
http://tcpreplay.synfin.net/ - Pcap editing and replay tools for Unix & Windows
Those who would give up essential Liberty, to purchase a little temporary
Safety, deserve neither Liberty nor Safety.
    -- Benjamin Franklin
"carpe diem quam minimum credula postero"

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