{
    "table_name": "Social_media_impact_on_life",
    "primary_key": "Student_ID",
    "candidates": [
        {
            "rank": 0,
            "partition_key": "Student_ID",
            "partition_key_label": "primary_identifier",
            "partition_key_reasoning": "Student_ID has 4500 unique values across 4500 rows (uniqueness 1.0, RPUV 1.00, 0% null). It is the unique identifier for each student record and the natural primary identifier for a dimension table. RPUV of 1 would be a poor partition choice for physical file splitting, but dimension rules designate the unique ID as primary_identifier.",
            "clustering_key": null,
            "clustering_key_label": null,
            "clustering_key_reasoning": "Dimension tables do not need internal sorting. There is no time axis; _ingestion_timestamp is constant (1 unique value) and carries no ordering information.",
            "world_line": null,
            "session_column": null,
            "confidence": "HIGH",
            "notes": "One row per student, with attributes (age, gender, academic level, platform, usage, sleep, stress, GPA, impact). Student_ID is a verified unique key. Other columns such as Academic_Level (RPUV 1500, top-3 coverage 100%), Gender and Device_Type are low-cardinality attributes, not identifiers. The _ingestion_timestamp, _batch_id, _source_file and _source_system columns are constant metadata."
        }
    ]
}