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
• Status: Closed
• Category: MySQL Server: Optimizer
• Severity: S3 (Non-critical)
• Version: 8.0.3
• OS: Any
• CPU Architecture: Any

[15 Jun 2017 11:57] Steinar Gunderson

Description:
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:
N/A

Suggested fix:
N/A

[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.