Bug #86716 Filesort uses hash for key even when no JSON is present
Submitted: 15 Jun 2017 11:57 Modified: 19 Jun 2017 11:39
Reporter: Steinar Gunderson Email Updates:
Status: Closed Impact on me:
Category:MySQL Server: Optimizer Severity:S3 (Non-critical)
Version:8.0.3 OS:Any
Assigned to: CPU Architecture:Any

[15 Jun 2017 11:57] Steinar Gunderson
Filesort adds a 64-bit hash value at the end of the key. This is meant for JSON, but it's also used when we have other variable-length keys, such as strings. (This is because when the code was written, JSON was the only variable-length key in question.) This is wasteful and should be removed.

How to repeat:

Suggested fix:
[15 Jun 2017 15:51] MySQL Verification Team
HI Steinar,

Is this bug a duplicate of #86517, which I have verified ????
[16 Jun 2017 8:42] Steinar Gunderson
No, it is unrelated.
[19 Jun 2017 11:39] Paul DuBois
Posted by developer:
Fixed in 8.0.3.

Code cleanup. No changelog entry needed.