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From "Shawn Du" <shawn...@neulion.com.cn>
Subject 答复: BinaryObject pros/cons
Date Fri, 28 Oct 2016 01:14:20 GMT



In one of our project, we compact java objects which have lots of long zeros. It save disk
greatly when serialization. 

Thus slow Disk IO operations become fast CPU operations and performance is improved.  

Data compact algorithm is inspired by this paper http://www.vldb.org/pvldb/vol8/p1816-teller.pdf.




发件人: Vladimir Ozerov [mailto:vozerov@gridgain.com] 
发送时间: 2016年10月28日 5:21
收件人: user@ignite.apache.org
主题: Re: BinaryObject pros/cons




I am not very concerned with null fields overhead, because usually it won't be significant.
However, there is a problem with zeros. User object might have lots of int/long zeros, this
is not uncommon. And each zero will consume 4-8 additional bytes. We probably will implement
special optimization which will write such fields in special compact format.




On Thu, Oct 27, 2016 at 10:55 PM, vkulichenko <valentin.kulichenko@gmail.com <mailto:valentin.kulichenko@gmail.com>
> wrote:


Yes, null values consume memory. I believe this can be optimized, but I
haven't seen issues with this so far. Unless you have hundreds of fields
most of which are nulls (very rare case), the overhead is minimal.


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