Distributed DBMS - CS712 Power Point Slides Lecture 35

To easy for a chained query most systems use single

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Unformatted text preview: eNo and EMP.eNo ASG.eNo = PROJ.eNo and ASG.eNo EMP.city = PROJ.city EMP.city PROJ.city ASG pNo eNo EMP city PROJ Cyclic Query ASG eNo, city EMP Tree Query pNo, city PROJ • Full Reducer may be hard Full to find. to • Easy for a chained query • Most systems use single Most SJs to reduce relation size. size. Distributed Query Processing Algorithms Processing • Three main Three representative algos are –Distributed INGRES Algorithm –R* Algorithm –SDD-1 Algorithm. R* Algorithm R* • Static, exhaustive • Algorithm supports Algorithm fragmentation, actual implementation doesn’t implementation • Master, execution and Master, apprentice sites. apprentice • Optimizer of Master site Optimizer makes inter-site decisions makes • Apprentice sites make local Apprentice decisi...
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