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:
Category:MySQL Server: Optimizer Severity:S3 (Non-critical)
Version: OS:Any
Assigned to: CPU Architecture:Any

[8 May 2017 13:51] Steinar Gunderson
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:

Suggested fix:
[9 May 2017 15:00] Paul DuBois
Posted by developer:
Fixed in 8.0.2.

Code cleanup. No changelog entry needed.