order_by_limit_trace_biglimit.json

{
  "steps": [
    {
      "join_preparation": {
        "select#": 1,
        "steps": [
          {
            "expanded_query": "/* select#1 */ select `t_tbl_test_time_08`.`f_some_id` AS `f_some_id` from `t_tbl_test_time_08` where ((`t_tbl_test_time_08`.`f_qiye_id` = 5077665) and (`t_tbl_test_time_08`.`f_type` = 9) and (`t_tbl_test_time_08`.`f_contact_time` > '2017-10-17 14:23:49') and (`t_tbl_test_time_08`.`f_contact_time` < '2017-10-17 14:23:53')) order by `t_tbl_test_time_08`.`f_some_id` limit 8168"
          }
        ]
      }
    },
    {
      "join_optimization": {
        "select#": 1,
        "steps": [
          {
            "condition_processing": {
              "condition": "WHERE",
              "original_condition": "((`t_tbl_test_time_08`.`f_qiye_id` = 5077665) and (`t_tbl_test_time_08`.`f_type` = 9) and (`t_tbl_test_time_08`.`f_contact_time` > '2017-10-17 14:23:49') and (`t_tbl_test_time_08`.`f_contact_time` < '2017-10-17 14:23:53'))",
              "steps": [
                {
                  "transformation": "equality_propagation",
                  "resulting_condition": "((`t_tbl_test_time_08`.`f_contact_time` > '2017-10-17 14:23:49') and (`t_tbl_test_time_08`.`f_contact_time` < '2017-10-17 14:23:53') and multiple equal(5077665, `t_tbl_test_time_08`.`f_qiye_id`) and multiple equal(9, `t_tbl_test_time_08`.`f_type`))"
                },
                {
                  "transformation": "constant_propagation",
                  "resulting_condition": "((`t_tbl_test_time_08`.`f_contact_time` > '2017-10-17 14:23:49') and (`t_tbl_test_time_08`.`f_contact_time` < '2017-10-17 14:23:53') and multiple equal(5077665, `t_tbl_test_time_08`.`f_qiye_id`) and multiple equal(9, `t_tbl_test_time_08`.`f_type`))"
                },
                {
                  "transformation": "trivial_condition_removal",
                  "resulting_condition": "((`t_tbl_test_time_08`.`f_contact_time` > '2017-10-17 14:23:49') and (`t_tbl_test_time_08`.`f_contact_time` < '2017-10-17 14:23:53') and multiple equal(5077665, `t_tbl_test_time_08`.`f_qiye_id`) and multiple equal(9, `t_tbl_test_time_08`.`f_type`))"
                }
              ]
            }
          },
          {
            "table_dependencies": [
              {
                "table": "`t_tbl_test_time_08`",
                "row_may_be_null": false,
                "map_bit": 0,
                "depends_on_map_bits": [
                ]
              }
            ]
          },
          {
            "ref_optimizer_key_uses": [
            ]
          },
          {
            "rows_estimation": [
              {
                "table": "`t_tbl_test_time_08`",
                "range_analysis": {
                  "table_scan": {
                    "rows": 18278388,
                    "cost": 3.71e6
                  },
                  "potential_range_indices": [
                    {
                      "index": "some_qiye_type",
                      "usable": false,
                      "cause": "not_applicable"
                    },
                    {
                      "index": "f_contact_time",
                      "usable": true,
                      "key_parts": [
                        "f_contact_time"
                      ]
                    }
                  ],
                  "setup_range_conditions": [
                  ],
                  "group_index_range": {
                    "chosen": false,
                    "cause": "not_group_by_or_distinct"
                  },
                  "analyzing_range_alternatives": {
                    "range_scan_alternatives": [
                      {
                        "index": "f_contact_time",
                        "ranges": [
                          "2017-10-17 14:23:49 < f_contact_time < 2017-10-17 14:23:53"
                        ],
                        "index_dives_for_eq_ranges": true,
                        "rowid_ordered": false,
                        "using_mrr": true,
                        "index_only": false,
                        "rows": 360478,
                        "cost": 414128,
                        "chosen": true
                      }
                    ],
                    "analyzing_roworder_intersect": {
                      "usable": false,
                      "cause": "too_few_roworder_scans"
                    }
                  },
                  "chosen_range_access_summary": {
                    "range_access_plan": {
                      "type": "range_scan",
                      "index": "f_contact_time",
                      "rows": 360478,
                      "ranges": [
                        "2017-10-17 14:23:49 < f_contact_time < 2017-10-17 14:23:53"
                      ]
                    },
                    "rows_for_plan": 360478,
                    "cost_for_plan": 414128,
                    "chosen": true
                  }
                }
              }
            ]
          },
          {
            "considered_execution_plans": [
              {
                "plan_prefix": [
                ],
                "table": "`t_tbl_test_time_08`",
                "best_access_path": {
                  "considered_access_paths": [
                    {
                      "access_type": "range",
                      "rows": 360478,
                      "cost": 486224,
                      "chosen": true
                    }
                  ]
                },
                "cost_for_plan": 486224,
                "rows_for_plan": 360478,
                "chosen": true
              }
            ]
          },
          {
            "attaching_conditions_to_tables": {
              "original_condition": "((`t_tbl_test_time_08`.`f_type` = 9) and (`t_tbl_test_time_08`.`f_qiye_id` = 5077665) and (`t_tbl_test_time_08`.`f_contact_time` > '2017-10-17 14:23:49') and (`t_tbl_test_time_08`.`f_contact_time` < '2017-10-17 14:23:53'))",
              "attached_conditions_computation": [
                {
                  "table": "`t_tbl_test_time_08`",
                  "rechecking_index_usage": {
                    "recheck_reason": "low_limit",
                    "limit": 8168,
                    "row_estimate": 360478
                  }
                }
              ],
              "attached_conditions_summary": [
                {
                  "table": "`t_tbl_test_time_08`",
                  "attached": "((`t_tbl_test_time_08`.`f_type` = 9) and (`t_tbl_test_time_08`.`f_qiye_id` = 5077665) and (`t_tbl_test_time_08`.`f_contact_time` > '2017-10-17 14:23:49') and (`t_tbl_test_time_08`.`f_contact_time` < '2017-10-17 14:23:53'))"
                }
              ]
            }
          },
          {
            "clause_processing": {
              "clause": "ORDER BY",
              "original_clause": "`t_tbl_test_time_08`.`f_some_id`",
              "items": [
                {
                  "item": "`t_tbl_test_time_08`.`f_some_id`"
                }
              ],
              "resulting_clause_is_simple": true,
              "resulting_clause": "`t_tbl_test_time_08`.`f_some_id`"
            }
          },
          {
            "refine_plan": [
              {
                "table": "`t_tbl_test_time_08`",
                "pushed_index_condition": "((`t_tbl_test_time_08`.`f_contact_time` > '2017-10-17 14:23:49') and (`t_tbl_test_time_08`.`f_contact_time` < '2017-10-17 14:23:53'))",
                "table_condition_attached": "((`t_tbl_test_time_08`.`f_type` = 9) and (`t_tbl_test_time_08`.`f_qiye_id` = 5077665))",
                "access_type": "range"
              }
            ]
          },
          {
            "reconsidering_access_paths_for_index_ordering": {
              "clause": "ORDER BY",
              "index_order_summary": {
                "table": "`t_tbl_test_time_08`",
                "index_provides_order": false,
                "order_direction": "undefined",
                "index": "f_contact_time",
                "plan_changed": false
              }
            }
          }
        ]
      }
    },
    {
      "join_execution": {
        "select#": 1,
        "steps": [
          {
            "filesort_information": [
              {
                "direction": "asc",
                "table": "`t_tbl_test_time_08`",
                "field": "f_some_id"
              }
            ],
            "filesort_priority_queue_optimization": {
              "limit": 8168,
              "rows_estimate": 43265832,
              "row_size": 19,
              "memory_available": 720896,
              "chosen": true
            },
            "filesort_execution": [
            ],
            "filesort_summary": {
              "rows": 8169,
              "examined_rows": 188155,
              "number_of_tmp_files": 0,
              "sort_buffer_size": 220563,
              "sort_mode": "<sort_key, additional_fields>"
            }
          }
        ]
      }
    }
  ]
}