Bug #84180 add more filesort information to optimizer trace

• Submitted: 13 Dec 2016 12:35
• Modified: 16 Dec 2016 20:02
• Reporter: Tor Didriksen
• Status: Closed
• Category: MySQL Server: Optimizer
• Severity: S3 (Non-critical)
• Version: 8.0.1
• OS: Any
• CPU Architecture: Any

[13 Dec 2016 12:35] Tor Didriksen

Description:
Add information about key/payload size, why we are not packing addon fields, etc.

How to repeat:
Read .result files for optimizer trace/filesort.

Suggested fix:
            "filesort_summary": {
              "memory_available": 262144,
              "key_size": 261,
              "row_size": 261,
              "max_rows_per_buffer": 15,
              "num_rows_estimate": 15,
              "num_rows_found": 0,
              "num_examined_rows": 0,
              "num_tmp_files": 0,
              "sort_buffer_size": 4040,
              "sort_algorithm": "none",
              "unpacked_addon_fields": "max_length_for_sort_data",
              "sort_mode": "<fixed_sort_key, rowid>"
            }

[16 Dec 2016 20:02] Paul DuBois

Posted by developer:
 
Noted in 8.0.1 changelog.

Optimizer trace output now includes more information about filesort
operations, such as key and payload size and why addon fields are not
packed.