Discuss the different techniques for executing an equijoin of two files located at different sites. What main factors affect the cost of data transfer?
Discuss the different techniques for executing an equijoin of two files located at different sites. What main factors affect the cost of data transfer?
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Technique 1: Transfer second table (from 2nd site) to 2nd table (first site) and join them, then transfer the result of join into site 3
Technique 2: Transfer 1st table (from 1st site) to the 2nd table (second site) and join them, then transfer the result of join into site 3
Main factors: We have to choose the site and table which contains less data in order to minimize the data transfer cost