Uwe L. Korn created ARROW-1123:
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             Summary: C++: Make jemalloc the default allocator
                 Key: ARROW-1123
                 URL: https://issues.apache.org/jira/browse/ARROW-1123
             Project: Apache Arrow
          Issue Type: New Feature
          Components: C++
            Reporter: Uwe L. Korn


While one of the advertised point of Arrow Java is that it comes with an 
efficient allocator that is based on jemalloc, we only provide jemalloc as an 
alternative allocator in C++. I would propose to switch to it as the default 
allocator on all platforms jemalloc is available (i.e. MacOS and Linux) as it 
provides the following benefits:

 * in-place resizing while ensuring 64byte alignment, for allocations >4kb this 
won't touch the data but rather only changes some pointers in kernel internal 
structs pointing to the respecitive memory pages.
 * better allocation algorithm, see 
https://www.facebook.com/notes/facebook-engineering/scalable-memory-allocation-using-jemalloc/480222803919/
 that should lead to less fragmentation and support fast multithreaded 
allocations

Especially for the builders, simply changing the allocator shows speedups 
between 2x and 10x. In the optimal case, this puts builders nearly on the same 
level as if one would have pre-allocated the final size.
 
This change should also include a blog post that outlines the benefits.



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