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From Alexander Shorin <>
Subject Re: Finding the right value for compaction configuration parameters
Date Sun, 20 Oct 2013 21:32:20 GMT
Hi Boaz!

On Fri, Oct 18, 2013 at 12:57 AM, Boaz Citrin <> wrote:
> Testing database compaction with various doc_buffer_size values I get
> completely different results.
> Documentation is fairly vague, so I wonder how to choose the right value;
> What parameters affect this - HD buffer size, average doc size,
> database size, fragmentation, etc... ?!
> Same goes for view compaction and keyvalue_buffer_size.

These parameters does affect on what they are named: they defines
buffer size for copying data from db/view file to the .compact one.
What information you think is missed?

> (For me the the compaction with default values was many times slower
> than with the values that gave the faster compaction).

All numbers have their cost: large buffers requires more memory while
they reduces I/O operations and vice versa. Much likely, that default
values wouldn't provide you high performance since they aimed to fit
everyone, but that's why you may tweak them for your needs (:

I believe, that it's possible to revise them, but first need to
collect information in what environment which values are effective and
which are not. Would you like to help us with that?


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