[MDEV-21163] Add filesort summary to the optimizer trace Created: 2019-11-28  Updated: 2023-12-05

Status: Stalled
Project: MariaDB Server
Component/s: Optimizer
Affects Version/s: 10.4
Fix Version/s: 10.4

Type: Bug Priority: Major
Reporter: Varun Gupta (Inactive) Assignee: Sergei Petrunia
Resolution: Unresolved Votes: 0
Labels: optimizer_trace


 Description   

MySQL prints information about filesort in the optimizer trace too

For a query SELECT * FROM t1 ORDER BY a desc, in the optimizer trace we see:

 
 
          {
 
            "filesort_information": [
 
              {
 
                "direction": "desc",
 
                "table": "`t1`",
 
                "field": "a"
 
              }
 
            ],
 
            "filesort_priority_queue_optimization": {
 
              "usable": false,
 
              "cause": "not applicable (no LIMIT)"
 
            },
 
            "filesort_execution": [
 
            ],
 
            "filesort_summary": {
 
              "rows": 100,
 
              "examined_rows": 100,
 
              "number_of_tmp_files": 0,
 
              "sort_buffer_size": 32456,
 
              "sort_mode": "<sort_key, packed_additional_fields>"
 
            }
 
          }

So it would be good to have the filesort summary also in the optimizer trace of MariaDB

 Comments   
Comment by Julien Fritsch [ 2023-12-05 ]

Automated message:
----------------------------
Since this issue has not been updated since 6 weeks, it's time to move it back to Stalled.

Comment by JiraAutomate [ 2023-12-05 ]

Automated message:
----------------------------
Since this issue has not been updated since 6 weeks, it's time to move it back to Stalled.

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