{
  "steps": [
    {
      "join_preparation": {
        "select#": 1,
        "steps": [
          {
            "expanded_query": "/* select#1 */ select `job_instances`.`jobState` AS `jobState`,`job_instances`.`status` AS `status` from `job_instances` where (`job_instances`.`jobName` = 'Ship_Christmas_Presents') order by `job_instances`.`jobInstanceId` desc limit 1"
          }
        ]
      }
    },
    {
      "join_optimization": {
        "select#": 1,
        "steps": [
          {
            "condition_processing": {
              "condition": "WHERE",
              "original_condition": "(`job_instances`.`jobName` = 'Ship_Christmas_Presents')",
              "steps": [
                {
                  "transformation": "equality_propagation",
                  "resulting_condition": "multiple equal('Ship_Christmas_Presents', `job_instances`.`jobName`)"
                },
                {
                  "transformation": "constant_propagation",
                  "resulting_condition": "multiple equal('Ship_Christmas_Presents', `job_instances`.`jobName`)"
                },
                {
                  "transformation": "trivial_condition_removal",
                  "resulting_condition": "multiple equal('Ship_Christmas_Presents', `job_instances`.`jobName`)"
                }
              ]
            }
          },
          {
            "table_dependencies": [
              {
                "table": "`job_instances`",
                "row_may_be_null": false,
                "map_bit": 0,
                "depends_on_map_bits": [
                ]
              }
            ]
          },
          {
            "ref_optimizer_key_uses": [
              {
                "table": "`job_instances`",
                "field": "jobName",
                "equals": "'Ship_Christmas_Presents'",
                "null_rejecting": false
              }
            ]
          },
          {
            "rows_estimation": [
              {
                "table": "`job_instances`",
                "range_analysis": {
                  "table_scan": {
                    "rows": 3849342,
                    "cost": 846030
                  },
                  "potential_range_indices": [
                    {
                      "index": "PRIMARY",
                      "usable": false,
                      "cause": "not_applicable"
                    },
                    {
                      "index": "jobId",
                      "usable": false,
                      "cause": "not_applicable"
                    },
                    {
                      "index": "jobName_State",
                      "usable": true,
                      "key_parts": [
                        "jobName",
                        "jobState",
                        "jobInstanceId"
                      ]
                    },
                    {
                      "index": "finishedRunningAt",
                      "usable": false,
                      "cause": "not_applicable"
                    },
                    {
                      "index": "taskId",
                      "usable": false,
                      "cause": "not_applicable"
                    },
                    {
                      "index": "jobStateUpdatedAt",
                      "usable": false,
                      "cause": "not_applicable"
                    },
                    {
                      "index": "parentJobInstanceId",
                      "usable": false,
                      "cause": "not_applicable"
                    },
                    {
                      "index": "jobState",
                      "usable": false,
                      "cause": "not_applicable"
                    },
                    {
                      "index": "hostname",
                      "usable": false,
                      "cause": "not_applicable"
                    },
                    {
                      "index": "jobState_2",
                      "usable": false,
                      "cause": "not_applicable"
                    }
                  ],
                  "setup_range_conditions": [
                  ],
                  "group_index_range": {
                    "chosen": false,
                    "cause": "not_group_by_or_distinct"
                  },
                  "analyzing_range_alternatives": {
                    "range_scan_alternatives": [
                      {
                        "index": "jobName_State",
                        "ranges": [
                          "Ship_Christmas_Presents <= jobName <= Ship_Christmas_Presents"
                        ],
                        "index_dives_for_eq_ranges": true,
                        "rowid_ordered": false,
                        "using_mrr": false,
                        "index_only": false,
                        "rows": 26936,
                        "cost": 32324,
                        "chosen": true
                      }
                    ],
                    "analyzing_roworder_intersect": {
                      "usable": false,
                      "cause": "too_few_roworder_scans"
                    }
                  },
                  "chosen_range_access_summary": {
                    "range_access_plan": {
                      "type": "range_scan",
                      "index": "jobName_State",
                      "rows": 26936,
                      "ranges": [
                        "Ship_Christmas_Presents <= jobName <= Ship_Christmas_Presents"
                      ]
                    },
                    "rows_for_plan": 26936,
                    "cost_for_plan": 32324,
                    "chosen": true
                  }
                }
              }
            ]
          },
          {
            "considered_execution_plans": [
              {
                "plan_prefix": [
                ],
                "table": "`job_instances`",
                "best_access_path": {
                  "considered_access_paths": [
                    {
                      "access_type": "ref",
                      "index": "jobName_State",
                      "rows": 26936,
                      "cost": 32323,
                      "chosen": true
                    },
                    {
                      "access_type": "range",
                      "cause": "heuristic_index_cheaper",
                      "chosen": false
                    }
                  ]
                },
                "cost_for_plan": 32323,
                "rows_for_plan": 26936,
                "chosen": true
              }
            ]
          },
          {
            "attaching_conditions_to_tables": {
              "original_condition": "(`job_instances`.`jobName` = 'Ship_Christmas_Presents')",
              "attached_conditions_computation": [
              ],
              "attached_conditions_summary": [
                {
                  "table": "`job_instances`",
                  "attached": "(`job_instances`.`jobName` = 'Ship_Christmas_Presents')"
                }
              ]
            }
          },
          {
            "clause_processing": {
              "clause": "ORDER BY",
              "original_clause": "`job_instances`.`jobInstanceId` desc",
              "items": [
                {
                  "item": "`job_instances`.`jobInstanceId`"
                }
              ],
              "resulting_clause_is_simple": true,
              "resulting_clause": "`job_instances`.`jobInstanceId` desc"
            }
          },
          {
            "refine_plan": [
              {
                "table": "`job_instances`",
                "pushed_index_condition": "(`job_instances`.`jobName` = 'Ship_Christmas_Presents')",
                "table_condition_attached": null
              }
            ]
          },
          {
            "added_back_ref_condition": "((`job_instances`.`jobName` <=> 'Ship_Christmas_Presents'))"
          },
          {
            "reconsidering_access_paths_for_index_ordering": {
              "clause": "ORDER BY",
              "index_order_summary": {
                "table": "`job_instances`",
                "index_provides_order": true,
                "order_direction": "desc",
                "disabled_pushed_condition_on_old_index": true,
                "index": "PRIMARY",
                "plan_changed": true,
                "access_type": "index_scan"
              }
            }
          }
        ]
      }
    },
    {
      "join_execution": {
        "select#": 1,
        "steps": [
        ]
      }
    }
  ]
}