"surrogate key" meaning in English

{
  "forms": [
    {
      "form": "surrogate keys",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "surrogate key (plural surrogate keys)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Entries with translation boxes",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Terms with Bulgarian translations",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "langcode": "en",
          "name": "Databases",
          "orig": "en:Databases",
          "parents": [],
          "source": "w"
        }
      ],
      "examples": [
        {
          "bold_text_offsets": [
            [
              91,
              104
            ]
          ],
          "text": "We weren't sure which columns in the table would have unique values, so we used a separate surrogate key as the primary key.",
          "type": "example"
        }
      ],
      "glosses": [
        "A unique identifier for an entity or object, not derived from application data."
      ],
      "id": "en-surrogate_key-en-noun-V9tvPeTx",
      "links": [
        [
          "database",
          "database"
        ],
        [
          "unique identifier",
          "unique identifier"
        ],
        [
          "entity",
          "entity"
        ],
        [
          "object",
          "object"
        ],
        [
          "application",
          "application"
        ],
        [
          "data",
          "data"
        ]
      ],
      "raw_glosses": [
        "(databases) A unique identifier for an entity or object, not derived from application data."
      ],
      "topics": [
        "computing",
        "databases",
        "engineering",
        "mathematics",
        "natural-sciences",
        "physical-sciences",
        "sciences"
      ],
      "translations": [
        {
          "code": "bg",
          "lang": "Bulgarian",
          "lang_code": "bg",
          "roman": "surogáten ključ",
          "sense": "Translations",
          "tags": [
            "masculine"
          ],
          "word": "сурога́тен ключ"
        }
      ]
    }
  ],
  "word": "surrogate key"
}

{
  "forms": [
    {
      "form": "surrogate keys",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "surrogate key (plural surrogate keys)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "English terms with usage examples",
        "Entries with translation boxes",
        "Pages with 1 entry",
        "Pages with entries",
        "Terms with Bulgarian translations",
        "Translation table header lacks gloss",
        "en:Databases"
      ],
      "examples": [
        {
          "bold_text_offsets": [
            [
              91,
              104
            ]
          ],
          "text": "We weren't sure which columns in the table would have unique values, so we used a separate surrogate key as the primary key.",
          "type": "example"
        }
      ],
      "glosses": [
        "A unique identifier for an entity or object, not derived from application data."
      ],
      "links": [
        [
          "database",
          "database"
        ],
        [
          "unique identifier",
          "unique identifier"
        ],
        [
          "entity",
          "entity"
        ],
        [
          "object",
          "object"
        ],
        [
          "application",
          "application"
        ],
        [
          "data",
          "data"
        ]
      ],
      "raw_glosses": [
        "(databases) A unique identifier for an entity or object, not derived from application data."
      ],
      "topics": [
        "computing",
        "databases",
        "engineering",
        "mathematics",
        "natural-sciences",
        "physical-sciences",
        "sciences"
      ]
    }
  ],
  "translations": [
    {
      "code": "bg",
      "lang": "Bulgarian",
      "lang_code": "bg",
      "roman": "surogáten ključ",
      "sense": "Translations",
      "tags": [
        "masculine"
      ],
      "word": "сурога́тен ключ"
    }
  ],
  "word": "surrogate key"
}