Bug #117037 | index dive estimate wrong | ||
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Submitted: | 23 Dec 2024 8:48 | Modified: | 9 Jan 12:05 |
Reporter: | jump mason | Email Updates: | |
Status: | Can't repeat | Impact on me: | |
Category: | MySQL Server | Severity: | S3 (Non-critical) |
Version: | 8.0 | OS: | Any |
Assigned to: | CPU Architecture: | Any |
[23 Dec 2024 8:48]
jump mason
[9 Jan 12:05]
MySQL Verification Team
Hi Mr. mason, Thank you for your bug report. We tried your test case and we could not repeat it. Here are our results: "rows_estimation": [ { "table": "`t1`", "range_analysis": { "table_scan": { "rows": 86, "cost": 10.95 }, "potential_range_indexes": [ { "index": "PRIMARY", "usable": true, "key_parts": [ "id", "c1", "c2", "c3" ] } ], "setup_range_conditions": [ ], "group_index_range": { "chosen": false, "cause": "not_group_by_or_distinct" }, "skip_scan_range": { "potential_skip_scan_indexes": [ { "index": "PRIMARY", "usable": false, "cause": "query_references_nonkey_column" } ] }, "analyzing_range_alternatives": { "range_scan_alternatives": [ { "index": "PRIMARY", "ranges": [ "id = 45" ], "index_dives_for_eq_ranges": true, "rowid_ordered": true, "using_mrr": false, "index_only": false, "in_memory": 1, "rows": 1, "cost": 0.36, "chosen": true } ], "analyzing_roworder_intersect": { "usable": false, "cause": "too_few_roworder_scans" } }, "chosen_range_access_summary": { "range_access_plan": { "type": "range_scan", "index": "PRIMARY", "rows": 1, "ranges": [ "id = 45" ] }, "rows_for_plan": 1, "cost_for_plan": 0.36, "chosen": true } } } ] Can't repeat.
[11 Feb 9:05]
Sam Ni
We were able to repeat using the test case provided by mason on 8.0.24 "range_scan_alternatives": [ { "index": "PRIMARY", "ranges": [ "45 <= id <= 45" ], "index_dives_for_eq_ranges": true, "rowid_ordered": true, "using_mrr": false, "index_only": false, "rows": 43, "cost": 4.58027, "chosen": true }
[11 Feb 12:25]
MySQL Verification Team
hi Mr. Ni, The fact that you repeated the problem on 8.0.24 is irrelevant. Current release of the version 8.0 is 8.0.41.