Current Proceedings on Technology

Yazarlar: Ciobanu (Iacob) Nicoleta Magdalena

Konular:-

Anahtar Kelimeler:Distributed database,Horizontal fragmentation,Technique,Results

Özet: Both in research and in the production activity, the distributed technologies have some advantages over centralized databases. But both contradictory tendencies (centralization and distribution) have beside some advantages also some disadvantages. The activity of data fragmentation, operation specific to the distributed databases, involves partitioning the database in disjoint fragments and the allocation of each fragment on a single node. The advantages in this case are reduced storage and communication costs. However, availability and data security are reduced, even if are better than in case of centralization. The decision to use a fragmented database is very important because it determines the execution performance of a distributed query. This paper presents a technique for horizontal fragmentation of a relation based on priority location of its attributes, by which we can take correct decisions of fragmentation in the initial phase based on the results gathered during the analysis phase without the help of empirical data about query execution. This technique can also be applied in later phases of a distributed database system for partitioning relations. Fragmentation is synchronized with the allocation and thus does not add additional complexity to allocate fragments on DDBMS's sites.

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