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From Jake Luciani <jak...@gmail.com>
Subject Re: Slow Reads
Date Tue, 26 Jul 2011 16:49:08 GMT
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.
>



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