{ "ref_optimizer_key_uses": [ { "table": "ttt", "field": "id2", "equals": "'8'", "null_rejecting": false } ] }, { "rows_estimation": [ { "table": "ttt", "range_analysis": { "table_scan": { "rows": 8237708, "cost": 4165346.818 }, "potential_range_indexes": [ { "index": "PRIMARY", "usable": false, "cause": "not applicable" }, { "index": "id2_ctime", "usable": true, "key_parts": ["id2", "ctime"] }, { "index": "time", "usable": true, "key_parts": ["ctime"] } ], "setup_range_conditions": [], "analyzing_range_alternatives": { "range_scan_alternatives": [ { "index": "id2_ctime", "ranges": ["(8,TTTTTT) < (id2,ctime) <= (8)"], "rowid_ordered": false, "using_mrr": false, "index_only": false, "rows": 74, "cost": 88.99557359, "chosen": true }, { "index": "time", "ranges": ["(TTTTTT) < (ctime)"], "rowid_ordered": false, "using_mrr": false, "index_only": false, "rows": 72, "cost": 86.58014767, "chosen": true } ], "analyzing_roworder_intersect": { "cause": "too few roworder scans" }, "analyzing_index_merge_union": [] }, "group_index_range": { "chosen": false, "cause": "no group by or distinct" }, "chosen_range_access_summary": { "range_access_plan": { "type": "range_scan", "index": "time", "rows": 72, "ranges": ["(TTTTTT) < (ctime)"] }, "rows_for_plan": 72, "cost_for_plan": 86.58014767, "chosen": true } } }, { "table": "ttt", "rowid_filters": [ { "key": "time", "build_cost": 3.599347275, "rows": 72 }, { "key": "id2_ctime", "build_cost": 3.730581759, "rows": 74 } ] }, { "selectivity_for_indexes": [ { "index_name": "time", "selectivity_from_index": 8.740295e-6 }, { "index_name": "id2_ctime", "selectivity_from_index": 8.983081e-6, "selectivity_multiplier": 1025552 } ], "selectivity_for_columns": [], "cond_selectivity": 8.052099e-5 } ] }, { "considered_execution_plans": [ { "plan_prefix": [], "table": "ttt", "best_access_path": { "considered_access_paths": [ { "access_type": "ref", "index": "id2_ctime", "rows": 1025552, "cost": 824471.8898, "chosen": true }, { "access_type": "range", "resulting_rows": 663.3084173, "cost": 1.79769e308, "chosen": false } ], "chosen_access_method": { "type": "ref", "records": 1025552, "cost": 824471.8898, "uses_join_buffering": false } }, "rows_for_plan": 1025552, "cost_for_plan": 1029582.29, "selectivity": 8.740295e-6, "estimated_join_cardinality": 8.963627261 } ] }, { "best_join_order": ["ttt"] }, { "substitute_best_equal": { "condition": "WHERE", "resulting_condition": "ttt.id2 = '8' and ttt.ctime > TTTTTT" } }, { "attaching_conditions_to_tables": { "attached_conditions_computation": [], "attached_conditions_summary": [ { "table": "ttt", "attached": "ttt.ctime > TTTTTT" } ] } }