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From aaron morton <aa...@thelastpickle.com>
Subject Re: Strange delay in query
Date Wed, 14 Nov 2012 04:14:04 GMT
Minor compactions will still be triggered whenever a size tier gets 4+ sstables (for the default
compaction strategy). So it does not affect new data. 

It just takes longer for the biggest size tier to get to 4 files. So it takes longer to compact
the big output from the major compaction. 

Assuming your data roughly follows a generational model, where newer data is written to often
and older data is mostly read from. This can mean garbage hanging around in the big old file
and *potentially* slowing things down. 

Cheers

-----------------
Aaron Morton
Freelance Developer
@aaronmorton
http://www.thelastpickle.com

On 14/11/2012, at 12:21 AM, André Cruz <andre.cruz@co.sapo.pt> wrote:

> On Nov 13, 2012, at 8:54 AM, aaron morton <aaron@thelastpickle.com> wrote:
> 
>>> I don't think that statement is accurate.
>> Which part ?
> 
> Probably this part:
> "After running a major compaction, automatic minor compactions are no longer triggered,
frequently requiring you to manually run major compactions on a routine basis."
> 
> From what I read what happens is that it takes a lot longer for minor compactions to
be triggered because 3 more files with the size equal to the compacted one have to be created?
> 
> André


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