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From Manu Zhang <>
Subject Re: get_range_slice gets no rowcache support?
Date Mon, 19 Nov 2012 07:12:11 GMT

On Wed, Nov 14, 2012 at 2:04 AM, Tyler Hobbs <> wrote:

> As far as I know, the row cache has never been populated by
> get_range_slices(), only normal gets/multigets.  The behavior is this way
> because get_range_slices() is almost exclusively used to page over an
> entire column family, which generally would not fit into the cache and
> would simply a) ruin your cache if used for gets (b) generate a lot of
> extra garbage, and (c) result in nothing but cache misses.
> With that said, I'm sure there are still a few use cases where using the
> cache would be beneficial, so I'm sure there's a ticket out there somewhere
> that presents a few options for supporting this.
> On Thu, Nov 8, 2012 at 8:39 PM, Manu Zhang <>wrote:
>> I did overlook something. get_range_slice will invoke cfs.getRawCachedRow
>> instead of cfs.getThroughCache. Hence, no row will be cached if it's not
>> present in the row cache. Well, this puzzles me further as to that how the
>> range of rows is expected to get stored into the row cache in the first
>> place.
>> Would someone please clarify it for me? Thanks in advance.
>> On Thu, Nov 8, 2012 at 3:23 PM, Manu Zhang <>wrote:
>>> I've asked this question before. And after reading the source codes, I
>>> find that get_range_slice doesn't query rowcache before reading from
>>> Memtable and SSTable. I just want to make sure whether I've overlooked
>>> something. If my observation is correct, what's the consideration here?
> --
> Tyler Hobbs
> DataStax <>

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