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From Boris Yen <yulin...@gmail.com>
Subject Re: row cache
Date Fri, 23 Aug 2013 02:40:22 GMT
If you are using off-heap memory for row cache, "all writes invalidate the
entire row" should be correct.

Boris


On Fri, Aug 23, 2013 at 8:32 AM, Robert Coli <rcoli@eventbrite.com> wrote:

> On Wed, Aug 14, 2013 at 10:56 PM, Faraaz Sareshwala <
> fsareshwala@quantcast.com> wrote:
>
>>
>>    - All writes invalidate the entire row (updates thrown out the cached
>>    row)
>>
>> This is not correct. Writes are added to the row, if it is in the row
> cache. If it's not in the row cache, the row is not added to the cache.
>
> Citation from jbellis on stackoverflow, because I don't have time to find
> a better one and the code is not obvious about it :
>
> http://stackoverflow.com/a/12499422
>
> I have yet to go through the source code for the row cache. I do plan to
>> do that. Can someone point me to documentation on the row cache internals?
>> All I've found online so far is small discussion about it and how to enable
>> it.
>>
>
> There is no such documentation, or at least if it exists I am unaware of
> it.
>
> In general, the rule of thumb is that the Row Cache should not be used
> unless the rows in question are :
>
> 1) Very hot in terms of access
> 2) Uniform in size
> 3) "Small"
>
> =Rob
>

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