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From Rob Coli <rc...@palominodb.com>
Subject Re: any ways to have compaction use less disk space?
Date Wed, 26 Sep 2012 00:35:28 GMT
On Sun, Sep 23, 2012 at 12:24 PM, Aaron Turner <synfinatic@gmail.com> wrote:
>> Leveled compaction've tamed space for us. Note that you should set
>> sstable_size_in_mb to reasonably high value (it is 512 for us with ~700GB
>> per node) to prevent creating a lot of small files.
>
> 512MB per sstable?  Wow, that's freaking huge.  From my conversations
> with various developers 5-10MB seems far more reasonable.   I guess it
> really depends on your usage patterns, but that seems excessive to me-
> especially as sstables are promoted.

700gb = 716800mb  / 5mb = 143360

150,000 sstables seem highly unlikely to be performant. As a simple
example of why, on the read path the bloom filter for every sstable
must be consulted...

=Rob

-- 
=Robert Coli
AIM&GTALK - rcoli@palominodb.com
YAHOO - rcoli.palominob
SKYPE - rcoli_palominodb

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