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From Priyanka Ganuthula <priya...@gmail.com>
Subject Re: Slow Reads
Date Tue, 26 Jul 2011 17:25:59 GMT
Supercolumn has two columns and each column has only one byte.
It is a bit faster but not significant.

On Tue, Jul 26, 2011 at 12:49 PM, Jake Luciani <jakers@gmail.com> wrote:

> It doesn't read the entire row, but it does read a section of the row from
> disk...
>
> How big is each supercolumn?  If you re-read the data does the query time
> get faster?
>
>
>
> On Tue, Jul 26, 2011 at 11:59 AM, Philippe <watcherfr@gmail.com> wrote:
>
>> i believe it's because it needs to read the whole row to get to your super
>> column.
>>
>> you might have to reconsider your model.
>> Le 26 juil. 2011 17:39, "Priyanka" <priya429@gmail.com> a écrit :
>>
>> >
>> > Hello All,
>> >
>> > I am doing some read tests on Cassandra on a single node.But they
>> > are turning up to be very slow.
>> > Here is the data model in detail.
>> > I am using a super column family.Cassandra has total 970 rows and each
>> row
>> > has 620901 super columns and each super column has 2 columns.Total data
>> in
>> > the database would be around 45GB.
>> > I am trying to retrieve the data of a particular super column[Trying to
>> pull
>> > the row key associated with the super column and the column values with
>> in
>> > the super column.
>> > It is taking 2.5 secs with java code and 4.7 secs with the python code.
>> >
>> > Here is the python code.
>> > result = col_fam.get_range(start="",
>> > finish="",columns=None,column_start="",column_finish
>> >
>> ="",column_reversed=False,column_count=2,row_count=None,include_timestamp=False,
>> > super_column='200003', read_consistency_level=None,buffer_size=None)
>> >
>> > This is very slow compared to MySQL.
>> > Am not sure whats going wrong here.Could some one let me know if there
>> is
>> > any problem with my model.
>> >
>> >
>> > Any help in this regard is highly appreciated.
>> >
>> > Thank you.
>> >
>> > Regards,
>> > Priyanka
>> >
>> >
>> >
>> >
>> >
>> > --
>> > View this message in context:
>> http://cassandra-user-incubator-apache-org.3065146.n2.nabble.com/Slow-Reads-tp6622680p6622680.html
>> > Sent from the cassandra-user@incubator.apache.org mailing list archive
>> at Nabble.com.
>>
>
>
>
> --
> http://twitter.com/tjake
>

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