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Two schedules are said to be view equivalent if the following three conditions hold: For any operation Ri(X) of Ti in S, if the value of X read by the operation has been written by an operation Wj(X) of Tj (or if it is the original value of X before the schedule started), the same ____ must hold for the value of X read by operation Ri(X) of Ti in S'.

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Final answer:

Two schedules are view equivalent if they satisfy certain conditions, including reading the same values for corresponding operations across those schedules, ensuring transaction consistency.

Step-by-step explanation:

Two schedules are said to be view equivalent if they meet certain consistency conditions in terms of the values read and written by transactions within a database system. The specific part of the question is about one of the conditions for view equivalence, which relates to the consistency of read operations across two schedules, S and S'. The missing word in the sentence 'For any operation Ri(X) of Ti in S, if the value of X read by the operation has been written by an operation Wj(X) of Tj (or if it is the original value of X before the schedule started), the same value must hold for the value of X read by operation Ri(X) of Ti in S'.' is 'value'. This means that for a schedule S' to be view equivalent to S, an operation that reads a value X in S must read the same value X in S'.

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