MySQL Bugs: #86216: Remove radixsort

Bug #86216	Remove radixsort
Submitted:	8 May 2017 13:51	Modified:	9 May 2017 15:00
Reporter:	Steinar Gunderson	Email Updates:
Status:	Closed	Impact on me:	None
Category:	MySQL Server: Optimizer	Severity:	S3 (Non-critical)
Version:		OS:	Any
Assigned to:		CPU Architecture:	Any

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Description:
We have special-purpose radixsort code for sorting very short keys, but in practical testing, std::stable_sort is now faster. Thus, we can just remove the radixsort.

Verified by sorting 50000 short records on an int field, which is supposed to be the poster child for radxisort; removing the code was 10–20% faster in single-threaded testing, and there should be yet more in multithreaded, due to less cache pressure.

How to repeat:
N/A

Suggested fix:
N/A

Posted by developer:
 
Fixed in 8.0.2.

Code cleanup. No changelog entry needed.