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        2021年數(shù)據(jù)庫(kù)系統(tǒng)工程師上午真題及答案解析(71-75)

        數(shù)據(jù)庫(kù)系統(tǒng)工程師 責(zé)任編輯:胡媛 2021-05-30

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        摘要:2021年數(shù)據(jù)庫(kù)系統(tǒng)工程師考試已結(jié)束,希賽小編為大家整理了2021年數(shù)據(jù)庫(kù)系統(tǒng)工程師上午真題及答案解析(71-75)。

        為方便廣大考生考后估分對(duì)答案,希賽網(wǎng)特向廣大學(xué)員和網(wǎng)友搜集整理了相關(guān)真題信息,供大家參考。收集完整2021年軟考數(shù)據(jù)庫(kù)系統(tǒng)工程師真題答案后,希賽網(wǎng)的老師也將在考后第一時(shí)間進(jìn)行真題答案解析,敬請(qǐng)廣大考友考后積極關(guān)注。

        現(xiàn)在要推薦給大家的是文字版2021年數(shù)據(jù)庫(kù)系統(tǒng)工程師上午真題及答案解析71-75題。

        ●When we talk about a database, we must differentiate between the database_ (71)_ ,which is the logical design of the database, and the database_ (72) , which is a snapshot of the data in the database at a given instant in time. The concept of a relation corresponds to the programming-language notion of a variable, while the concept of a relation schema corresponds to the programming-language notion of type definition. In general, a relation schema consists of a listof(73)and their corresponding domains. The concept of a relation instance corresponds to the programming-language notion of a value of a (74) . The valueof a given variable may change with time; similarly the contents of a relation instance may change with time as the relation is updated. In contrast, the_ (75) оfa relation does not generally change.

        (71)A.schema

        B.instance

        C.table

        D.entity

        (72)A.schema

        B.table

        C.instance

        D.entity

        (73)

        A.variable

        B.attributes

        C.rows

        D.notions

        (74)A.constant

        B.variable

        C.struct

        D.array

        (75)A.table

        B.schema

        C.instance

        D.view

        2021年數(shù)據(jù)庫(kù)系統(tǒng)工程師上午真題及答案解析【完整版】請(qǐng)大家點(diǎn)擊下載附件查看,或-掃碼-看答案,提前估分!

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