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From aaron morton <aa...@thelastpickle.com>
Subject Re: Unable to fetch large amount of rows
Date Tue, 19 Mar 2013 07:40:53 GMT
>  I have 1000 timestamps, and for each timestamp, I have 500K different MACAddress.
So you are trying to read about 2 million columns ? 
500K MACAddresses each with 3 other columns? 

> When I run the following query, I get RPC Timeout exceptions:
What is the exception? 
Is it a client side socket timeout or a server side TimedOutException ?

If my understanding is correct then try reading fewer columns and/or check the server side
for logs. It sounds like you are trying to read too much though. 

Cheers



-----------------
Aaron Morton
Freelance Cassandra Consultant
New Zealand

@aaronmorton
http://www.thelastpickle.com

On 19/03/2013, at 3:51 AM, Pushkar Prasad <pushkar.prasad@airtightnetworks.net> wrote:

> Hi,
>  
> I have following schema:
>  
> TimeStamp
> MACAddress
> Data Transfer
> Data Rate
> LocationID
>  
> PKEY is (TimeStamp, MACAddress). That means partitioning is on TimeStamp, and data is
ordered by MACAddress, and stored together physically (let me know if my understanding is
wrong). I have 1000 timestamps, and for each timestamp, I have 500K different MACAddress.
>  
> When I run the following query, I get RPC Timeout exceptions:
>  
>  
> Select * from db_table where Timestamp=’…..’
>  
> From my understanding, this should give all the rows with just one disk seek, as all
the records for a particular timeStamp. This should be very quick, however, clearly, that
doesn’t seem to be the case. Is there something I am missing here? Your help would be greatly
appreciated.
>  
> Thanks
> PP


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