Overview of distributed query processing processing - - PowerPoint PPT Presentation

Overview of distributed query processing processing

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Outline (distributed DB)

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⋆ Özsu and Valduriez, (3rd Ed.), 2011

Query Processing in a D(DBMS

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• Selecting Alternatives
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What are the Additional Problems?

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EMP1= σENO≤“E3”(EMP) EMP2= σENO>“E3”(EMP) ASG2 σENO>“E3”(ASG) ASG1=σENO≤“E3”(ASG) Result

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ASG1 EMP1 EMP2 ASG2

result= (EMP1 ∪ EMP2)⋈ENOσRESP=“Manager”(ASG1 ∪ ASG2)

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Cost of Alternatives

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Query Optimization Objectives in DDBS

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Distributed Query Processing Methodology

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