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From "Benjamin Lerer (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (CASSANDRA-8899) cqlsh - not able to get row count with select(*) for large table
Date Thu, 26 Mar 2015 08:46:52 GMT

    [ https://issues.apache.org/jira/browse/CASSANDRA-8899?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14381582#comment-14381582
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Benjamin Lerer commented on CASSANDRA-8899:
-------------------------------------------

[~jeffl] Could you check the effect of increasing the timeout?

By default the page size is of 10 000  rows and count is performed on the coordinator node.
This means that if the data are not on your coordinator node it will have to send at least
5 queries (more if the data are distributed over several nodes) to the other nodes. Depending
how far your nodes are from the coordinator the latency can add up pretty quickly.

The best way for you to verify this theory will be to use request tracing: http://www.datastax.com/dev/blog/tracing-in-cassandra-1-2
 


> cqlsh - not able to get row count with select(*) for large table
> ----------------------------------------------------------------
>
>                 Key: CASSANDRA-8899
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-8899
>             Project: Cassandra
>          Issue Type: Bug
>         Environment: Cassandra 2.1.2 ubuntu12.04
>            Reporter: Jeff Liu
>            Assignee: Benjamin Lerer
>
>  I'm getting errors when running a query that looks at a large number of rows.
> {noformat}
> cqlsh:events> select count(*) from catalog;
>  count
> -------
>  10000
> (1 rows)
> cqlsh:events> select count(*) from catalog limit 11000;
>  count
> -------
>  11000
> (1 rows)
> cqlsh:events> select count(*) from catalog limit 50000;
> errors={}, last_host=127.0.0.1
> cqlsh:events> 
> {noformat}
> We are not able to make the select * query to get row count.



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