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From Apoorva Gaurav <>
Subject Re: Read performance in map data type
Date Fri, 04 Apr 2014 05:41:34 GMT
On Fri, Apr 4, 2014 at 3:32 AM, Robert Coli <> wrote:

> On Thu, Apr 3, 2014 at 12:20 AM, Apoorva Gaurav <
> > wrote:
>> At the client side we are getting a latency of ~350ms, we are using
>> datastax driver 2.0.0 and have kept the fetch size as 500. And these are
>> coming while reading rows having ~200 columns.
> And you're sure that the 300ms between what cassandra reports and what
> your app reports are not just network/serialization time?
We are using the datastax 2.0.0 driver. This latency is for the execute
command. We already have the prepared statement cached in app layer before
calling execute.

> What do you believe the latency "should" be?
If we store the same data as a json using text data type i.e (studentID
int, subjectMarksJson text) we are getting a latency of ~10ms from the same
client for even bigger. I understand that json is not the preferred storage
for cassandra and will loose various flexibility which a proper tabular
approach provides. But such a huge jump in read latency is killer. I'm
pastebin-ing the histogram for json storage as well

> =Rob

Thanks & Regards,

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