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https://issues.apache.org/jira/browse/CASSANDRA-8574?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Jens Rantil updated CASSANDRA-8574:
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    Summary: Gracefully degrade SELECT when there are lots of tombstones  (was: 
Gracefully degrade when there are lots of tombstones)

> Gracefully degrade SELECT when there are lots of tombstones
> -----------------------------------------------------------
>
>                 Key: CASSANDRA-8574
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-8574
>             Project: Cassandra
>          Issue Type: Improvement
>            Reporter: Jens Rantil
>
> *Background:* There's lots of tooling out there to do BigData analysis on 
> Cassandra clusters. Examples are Spark and Hadoop, which is offered by DSE. 
> The problem with both of these so far, is that a single partition key with 
> too many tombstones can make the query job fail hard.
> The describe scenario happens despite the user setting a rather small 
> PageSize. I assume this is a common scenario if you have a larger rows.
> *Proposal:* To allow a CQL SELECT to gracefully degrade to only return a 
> smaller batch of results if there are too many tombstones. The tombstones are 
> ordered according to clustering key and one should be able to page through 
> them. Potentially:
>     SELECT * FROM mytable LIMIT 1000 TOMBSTONES;
> would page through maximum 1000 tombstones, _or_ 1000 (CQL) rows.
> I understand that this obviously would degrade performance, but it would at 
> least yield a result.
> Additional comment: I haven't dug into Cassandra code, but conceptually I 
> guess this would be doable. Let me know what you think.



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