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https://issues.apache.org/jira/browse/CASSANDRA-5357?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13773111#comment-13773111
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Jonathan Ellis commented on CASSANDRA-5357:
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Getting back to this now that 2.0.1 is done. Sounds reasonable in general.
Comments:
# I don't think dropping RowCacheSentinel is valid, unfortunately. Otherwise
we still have the same problem as CASSANDRA-3862. (Write can invalidate the
row, just before cache adds the pre-write value to it, so stale data will be
cached indefinitely.)
# Serializing the entire QueryCacheValue for each lookup is going to kill
performance on hot partitions. (Since you have to deserialize a large chunk of
filters to just do the existence check.) Suggest that serializing just the CF
data is going to work better.
# {{TODO do something here}} looks important :)
# "There could be any number of queries but the data will not be repeated
within them." Clever.
# "There is a property which user can enable to cache the whole row." Not
really a fan but I guess existing row cache users will demand it. :-|
# "we might be pulling the whole data into memory" -- if there's room, that's
fine, but exceeding the configured memory budget is Bad. As long as we don't
do that I'm fine.
> Query cache
> -----------
>
> Key: CASSANDRA-5357
> URL: https://issues.apache.org/jira/browse/CASSANDRA-5357
> Project: Cassandra
> Issue Type: Bug
> Reporter: Jonathan Ellis
> Assignee: Vijay
>
> I think that most people expect the row cache to act like a query cache,
> because that's a reasonable model. Caching the entire partition is, in
> retrospect, not really reasonable, so it's not surprising that it catches
> people off guard, especially given the confusion we've inflicted on ourselves
> as to what a "row" constitutes.
> I propose replacing it with a true query cache.
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