{
    "role": "dimension",
    "time": {
        "range": null,
        "column": null,
        "has_gaps": null,
        "granularity": "unknown"
    },
    "grain": [
        "account_id",
        "service_point_id"
    ],
    "table": "data-ge.water_meter_info",
    "columns": [
        {
            "name": "supply_office",
            "dtype": "string",
            "stats": {},
            "comment": "供水管理所名称，枚举值",
            "enumish": true,
            "null_rate": 0.0,
            "top_values": [
                {
                    "pct": null,
                    "value": "宝山供水管理所"
                },
                {
                    "pct": null,
                    "value": "黄浦供水管理所"
                },
                {
                    "pct": null,
                    "value": "青东供水管理所"
                },
                {
                    "pct": null,
                    "value": "虹口供水管理所"
                },
                {
                    "pct": null,
                    "value": "闸北供水管理所"
                },
                {
                    "pct": null,
                    "value": "松北供水管理所"
                },
                {
                    "pct": null,
                    "value": "杨浦供水管理所"
                },
                {
                    "pct": null,
                    "value": "长宁供水管理所"
                },
                {
                    "pct": null,
                    "value": "闵行供水管理所"
                },
                {
                    "pct": null,
                    "value": "徐汇供水管理所"
                },
                {
                    "pct": null,
                    "value": "普陀供水管理所"
                }
            ],
            "semantic_type": "dimension",
            "distinct_count": 11,
            "distinct_ratio": 0.03666666666666667,
            "pk_candidate_score": 0.11,
            "metric_candidate_score": 0.0
        },
        {
            "name": "station",
            "dtype": "string",
            "stats": {},
            "comment": "站点名称，枚举值",
            "enumish": true,
            "null_rate": 0.0,
            "top_values": [
                {
                    "pct": null,
                    "value": "新闸站"
                },
                {
                    "pct": null,
                    "value": "宝杨站"
                },
                {
                    "pct": null,
                    "value": "江川站"
                },
                {
                    "pct": null,
                    "value": "长江站"
                },
                {
                    "pct": null,
                    "value": "市光站"
                },
                {
                    "pct": null,
                    "value": "徐泾站"
                },
                {
                    "pct": null,
                    "value": "真北站"
                },
                {
                    "pct": null,
                    "value": "半淞园站"
                },
                {
                    "pct": null,
                    "value": "芙蓉江站"
                },
                {
                    "pct": null,
                    "value": "密云站"
                }
            ],
            "semantic_type": "dimension",
            "distinct_count": 36,
            "distinct_ratio": 0.12,
            "pk_candidate_score": 0.36,
            "metric_candidate_score": 0.0
        },
        {
            "name": "district",
            "dtype": "string",
            "stats": {},
            "comment": "行政区划名称，枚举值",
            "enumish": true,
            "null_rate": 0.0,
            "top_values": [
                {
                    "pct": null,
                    "value": "普陀区"
                },
                {
                    "pct": null,
                    "value": "闵行区"
                },
                {
                    "pct": null,
                    "value": "嘉定区"
                },
                {
                    "pct": null,
                    "value": "杨浦区"
                },
                {
                    "pct": null,
                    "value": "徐汇区"
                },
                {
                    "pct": null,
                    "value": "黄浦区"
                },
                {
                    "pct": null,
                    "value": "松江区"
                },
                {
                    "pct": null,
                    "value": "长宁区"
                },
                {
                    "pct": null,
                    "value": "青浦区"
                },
                {
                    "pct": null,
                    "value": "虹口区"
                }
            ],
            "semantic_type": "dimension",
            "distinct_count": 13,
            "distinct_ratio": 0.043333333333333335,
            "pk_candidate_score": 0.13,
            "metric_candidate_score": 0.0
        },
        {
            "name": "meter_diameter",
            "dtype": "string",
            "stats": {},
            "comment": "水表直径规格，枚举值",
            "enumish": true,
            "null_rate": 0.0,
            "top_values": [
                {
                    "pct": null,
                    "value": "20mm"
                },
                {
                    "pct": null,
                    "value": "15mm"
                },
                {
                    "pct": null,
                    "value": "25mm"
                },
                {
                    "pct": null,
                    "value": "40mm"
                },
                {
                    "pct": null,
                    "value": "150mm"
                },
                {
                    "pct": null,
                    "value": "100mm"
                },
                {
                    "pct": null,
                    "value": "80mm"
                },
                {
                    "pct": null,
                    "value": "50mm"
                }
            ],
            "semantic_type": "dimension",
            "distinct_count": 8,
            "distinct_ratio": 0.02666666666666667,
            "pk_candidate_score": 0.08,
            "metric_candidate_score": 0.0
        },
        {
            "name": "meter_status",
            "dtype": "string",
            "stats": {},
            "comment": "水表状态，枚举值",
            "enumish": true,
            "null_rate": 0.0,
            "top_values": [
                {
                    "pct": null,
                    "value": "有效"
                }
            ],
            "semantic_type": "dimension",
            "distinct_count": 1,
            "distinct_ratio": 0.0033333333333333335,
            "pk_candidate_score": 0.01,
            "metric_candidate_score": 0.0
        },
        {
            "name": "meter_subtype",
            "dtype": "string",
            "stats": {},
            "comment": "水表子类型，枚举值",
            "enumish": true,
            "null_rate": 0.0,
            "top_values": [
                {
                    "pct": null,
                    "value": "旋翼半液封式"
                },
                {
                    "pct": null,
                    "value": "超声波式"
                },
                {
                    "pct": null,
                    "value": "旋翼湿式（指针式）"
                },
                {
                    "pct": null,
                    "value": "旋翼湿式（数字指针式）"
                },
                {
                    "pct": null,
                    "value": "电磁式"
                },
                {
                    "pct": null,
                    "value": "无直管段要求超声波式"
                },
                {
                    "pct": null,
                    "value": "无直管段要求电磁式"
                },
                {
                    "pct": null,
                    "value": "垂直螺翼干式"
                },
                {
                    "pct": null,
                    "value": "机械容积式"
                }
            ],
            "semantic_type": "dimension",
            "distinct_count": 9,
            "distinct_ratio": 0.03,
            "pk_candidate_score": 0.09,
            "metric_candidate_score": 0.0
        },
        {
            "name": "meter_type",
            "dtype": "string",
            "stats": {},
            "comment": "水表类型，枚举值",
            "enumish": true,
            "null_rate": 0.0,
            "top_values": [
                {
                    "pct": null,
                    "value": "容积式机械水表"
                },
                {
                    "pct": null,
                    "value": "速度式机械水表"
                },
                {
                    "pct": null,
                    "value": "电磁式远传水表"
                },
                {
                    "pct": null,
                    "value": "速度式机电远传水表"
                },
                {
                    "pct": null,
                    "value": "超声波式远传水表"
                }
            ],
            "semantic_type": "dimension",
            "distinct_count": 5,
            "distinct_ratio": 0.016666666666666666,
            "pk_candidate_score": 0.05,
            "metric_candidate_score": 0.0
        },
        {
            "name": "installation_position",
            "dtype": "string",
            "stats": {},
            "comment": "安装位置，枚举值",
            "enumish": true,
            "null_rate": 0.0,
            "top_values": [
                {
                    "pct": null,
                    "value": "嵌墙表"
                },
                {
                    "pct": null,
                    "value": "管道井表"
                },
                {
                    "pct": null,
                    "value": "地下表"
                },
                {
                    "pct": null,
                    "value": "龙头表"
                }
            ],
            "semantic_type": "dimension",
            "distinct_count": 4,
            "distinct_ratio": 0.013333333333333334,
            "pk_candidate_score": 0.04,
            "metric_candidate_score": 0.0
        },
        {
            "name": "account_id",
            "dtype": "string",
            "stats": {},
            "comment": "账户ID",
            "enumish": false,
            "null_rate": null,
            "top_values": [],
            "semantic_type": "id",
            "distinct_count": null,
            "distinct_ratio": null,
            "pk_candidate_score": 0.95,
            "metric_candidate_score": 0.0
        },
        {
            "name": "service_point_id",
            "dtype": "string",
            "stats": {},
            "comment": "服务点ID",
            "enumish": false,
            "null_rate": null,
            "top_values": [],
            "semantic_type": "id",
            "distinct_count": null,
            "distinct_ratio": null,
            "pk_candidate_score": 0.95,
            "metric_candidate_score": 0.0
        }
    ],
    "quality": {
        "warning_hints": [],
        "failed_expectations": []
    },
    "row_count": 300,
    "fk_candidates": [],
    "confidence_notes": [
        "role判定为dimension，因所有列均为枚举或ID类型，无metric列",
        "grain依据account_id和service_point_id为唯一标识推测",
        "未发现时间列，因此time字段为null"
    ],
    "primary_key_candidates": [
        [
            "account_id"
        ],
        [
            "service_point_id"
        ]
    ]
}