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From Francisco Nogueira Calmon Sobral <fsob...@igcorp.com.br>
Subject Re: Slow retrieval using secondary indexes
Date Fri, 03 May 2013 12:11:40 GMT
Thanks!

The creation of the new CF worked pretty well and fast! Unfortunately, I was unable to trace
the request made using secondary indexes:

cqlsh:Sessions> select * from "Items" where key = '687474703a2f2f6573706f7';

 key                    | mahoutItemid
------------------------+--------------------
 687474703a2f2f6573706f7| 610866442877251584


Tracing session: b0240a40-b3e9-11e2-a219-59599925ed5a

 activity           | timestamp    | source       | source_elapsed
--------------------+--------------+--------------+----------------
 execute_cql3_query | 09:05:03,845 | 10.32.63.148 |              0
  Parsing statement | 09:05:03,845 | 10.32.63.148 |             36
 Peparing statement | 09:05:03,845 | 10.32.63.148 |            232
      Row cache hit | 09:05:03,845 | 10.32.63.148 |            577
   Request complete | 09:05:03,845 | 10.32.63.148 |            785

cqlsh:Sessions> select * from "Items" where "mahoutItemid" = 610866442877251584;

 key                    | mahoutItemid
------------------------+--------------------
 687474703a2f2f6573706f7| 610866442877251584

unsupported operand type(s) for /: 'NoneType' and 'float'


Regards,
Francisco Sobral


On Apr 28, 2013, at 4:55 PM, aaron morton <aaron@thelastpickle.com> wrote:

> Try the request tracing in 1.2 http://www.datastax.com/dev/blog/tracing-in-cassandra-1-2
it may point to the different. 
> 
>> In our model the secondary index in also unique, as the primary key is. Is it better,
in this case, to create another CF mapping the secondary index to the key?
> IMHO if you have a request that is frequently used as part of a hot code path it is still
a good idea to support that with a custom CF. 
> 
> Cheers
> 
> -----------------
> Aaron Morton
> Freelance Cassandra Consultant
> New Zealand
> 
> @aaronmorton
> http://www.thelastpickle.com
> 
> On 27/04/2013, at 12:27 AM, Francisco Nogueira Calmon Sobral <fsobral@igcorp.com.br>
wrote:
> 
>> Hi all!
>> 
>> We are using Cassandra 1.2.1 with a 8 node cluster running at Amazon. We started
with 6 nodes and added the 2 later. When performing some reads in Cassandra, we observed a
high difference between gets using the primary key and gets using secondary indexes:
>> 
>> 
>> [default@Sessions] get Users where mahoutUserid = 30127944399716352;
>> -------------------
>> RowKey: STQ0TTNII2LS211YYJI4GEV80M1SE8
>> => (column=mahoutUserid, value=30127944399716352, timestamp=1366820944696000)
>> 
>> 1 Row Returned.
>> Elapsed time: 3508 msec(s).
>> 
>> [default@Sessions] get Users['STQ0TTNII2LS211YYJI4GEV80M1SE8'];
>> => (column=mahoutUserid, value=30127944399716352, timestamp=1366820944696000)
>> Returned 1 results.
>> 
>> Elapsed time: 3.06 msec(s).
>> 
>> 
>> In our model the secondary index in also unique, as the primary key is. Is it better,
in this case, to create another CF mapping the secondary index to the key?
>> 
>> Best regards,
>> Francisco Sobral.
> 


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