{
    "classifications": [
        {
            "column": "_unnamed_0",
            "label": "primary_key",
            "confidence": 0.97,
            "reason": "100% distinct, no nulls, sequential index 0..422728 equal to row count"
        },
        {
            "column": "company_name",
            "label": "foreign_key",
            "confidence": 0.5,
            "reason": "152 distinct values repeating across rows; identifies the company entity and would join to a company dimension"
        },
        {
            "column": "stock_name",
            "label": "foreign_key",
            "confidence": 0.55,
            "reason": "Ticker symbol with 152 repeating values; a join column to a securities table"
        },
        {
            "column": "date",
            "label": "none",
            "confidence": 0.85,
            "reason": "Date dimension with repeated values; only part of a composite key with ticker, not a key on its own"
        },
        {
            "column": "open",
            "label": "none",
            "confidence": 0.95,
            "reason": "Numeric price measure"
        },
        {
            "column": "high",
            "label": "none",
            "confidence": 0.95,
            "reason": "Numeric price measure"
        },
        {
            "column": "low",
            "label": "none",
            "confidence": 0.95,
            "reason": "Numeric price measure"
        },
        {
            "column": "close",
            "label": "none",
            "confidence": 0.95,
            "reason": "Numeric price measure"
        },
        {
            "column": "volume",
            "label": "none",
            "confidence": 0.95,
            "reason": "Numeric trading volume measure"
        }
    ]
}