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https://issues.apache.org/jira/browse/CASSANDRA-5336?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13601132#comment-13601132
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Jonathan Ellis commented on CASSANDRA-5336:
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I guess I didn't read very carefully; I assumed that it would be using 
{{get_count}} on the Thrift side, which auto-pages to avoid this problem.  If 
you're going to use get_range_slices, then as Sylvain says you [which is to 
say, Simba] need to do your own paging to avoid OOM.
                
> C* crashes with an OOM error when using the Simba Driver on a very wide table
> -----------------------------------------------------------------------------
>
>                 Key: CASSANDRA-5336
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-5336
>             Project: Cassandra
>          Issue Type: Bug
>          Components: API
>    Affects Versions: 1.1.6
>         Environment: C* on a Mac with 1GB VM.  Simba ODBC driver
>            Reporter: Steven Lowenthal
>         Attachments: nhanes600-10k.tarZ, thrift.in, thrift.out
>
>
> The Simba driver executes a version of a count(*) query:
> SELECT SUM(1) from nhanes3 having sum(1) > 0.   It uses this format so ODBC 
> returns a no rows found error if the table is empty.   It translates into a 
> series of get_range_slice calls which bring back all of the rows, and for 
> every row, it brings back every single column name.   C* crashes with an OOM 
> in the thrift code.  The table has almost 600 columns of mixed text and 
> numeric data with many empty values.

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