Explain the concept of a semi-join using an example

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teamques10 ★ 70k

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distributed databases

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written 8.8 years ago by

teamques10 ★ 70k

The semi-Join of two relations R and S is denoted as R SJ_FS, where F is a formula which specifies a join predicate. A semi-join is derived from projection and join as follows:

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where Attr(R) denotes the set of all attributes of R. Thus, the result of the semi-join is …

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