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https://issues.apache.org/jira/browse/CASSANDRA-1956?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Stu Hood updated CASSANDRA-1956:
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    Comment: was deleted

(was: Thanks for the patch Daniel! We actually have existing 'filter' 
implementations (in {{org.apache.cassandra.db.filter}}) that I think would make 
the most sense for use aside cache entries.

> What about just invalidating (removing from the cache) the row on delete and 
> letting it get rebuild on the next read?
Also, regarding the "tombstones in cache" problem: I believe it came up in IRC 
the other day. The solution that seemed closest to our existing methods was to 
keep the tombstones in cache, but to add a thread that periodically walked the 
cache to perform GC (with our existing GC timeout) like we would during 
compaction.)

> Convert row cache to row+filter cache
> -------------------------------------
>
>                 Key: CASSANDRA-1956
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-1956
>             Project: Cassandra
>          Issue Type: Improvement
>          Components: Core
>    Affects Versions: 0.7.0
>            Reporter: Stu Hood
>            Assignee: Daniel Doubleday
>             Fix For: 0.7.2
>
>         Attachments: 0001-row-cache-filter.patch
>
>
> Changing the row cache to a row+filter cache would make it much more useful. 
> We currently have to warn against using the row cache with wide rows, where 
> the read pattern is typically a peek at the head, but this usecase would be 
> perfect supported by a cache that stored only columns matching the filter.
> Possible implementations:
> * (copout) Cache a single filter per row, and leave the cache key as is
> * Cache a list of filters per row, leaving the cache key as is: this is 
> likely to have some gotchas for weird usage patterns, and it requires the 
> list overheard
> * Change the cache key to "rowkey+filterid": basically ideal, but you need a 
> secondary index to lookup cache entries by rowkey so that you can keep them 
> in sync with the memtable
> * others?

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