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From Sylvain Lebresne <sylv...@datastax.com>
Subject Re: Slow Reads
Date Tue, 26 Jul 2011 16:57:38 GMT
On Tue, Jul 26, 2011 at 5:39 PM, Priyanka <priya429@gmail.com> wrote:
>
> 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)

What are you trying to query exactly ? All the rows or only one ?
Because I'm no expert in pycassa but if read this code and pycassa
code correctly,
request will query 1024 rows upfront and return an iterator that will
eventually read
all the rows in the database if you iter.


> 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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