1 / 18

Distributed Database Management Systems

Distributed Database Management Systems . Lecture 13. How. Interests of the local and head offices mar result following vertical partitions of this table: EMP1(eId, eName, eDept) EMP2(eId, eQual, eSal). 1- Vertical; Different subsets of attributes are stored at different places, like,

talisa
Download Presentation

Distributed Database Management Systems

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Distributed Database Management Systems Lecture 13

  2. How Interests of the local and head offices mar result following vertical partitions of this table: EMP1(eId, eName, eDept) EMP2(eId, eQual, eSal) Virtual University of Pakistan

  3. 1- Vertical; Different subsets of attributes are stored at different places, like, Table EMP(eId, eName, eDept, eQual, eSal) Virtual University of Pakistan

  4. Interests of the local and head offices may result following vertical partitions of this table: EMP1(eId, eName, eDept) EMP2(eId, eQual, eSal) Virtual University of Pakistan

  5. CLIENT (cAC#, cName, cAdr, cBal) table is placed in different databases based on their location, like from Lahore, Pindi, Karachi, Peshawar, Quetta Virtual University of Pakistan

  6. 3- Degree of Fragmentation Between no to the extreme level that could be to the individual tuple or column level; a compromised decision Virtual University of Pakistan

  7. 4- Correctness Rules for Fragmentation Virtual University of Pakistan

  8. Completeness: each of the data item (a tuple or a attribute) that can be in R can also be in one or more Ri ∀ x ∈ R, ∃ Ri such that x ∈ Ri Resembles Lossless decomposition property in Normalization Virtual University of Pakistan

  9. Reconstruction: it should be possible to define a relational operator such that the original relation can be reconstructed R = g(R1, R2, …, Rn) Reconstruction ensures that the dependencies of the original relation are preserved in fragmentation Virtual University of Pakistan

  10. Disjoint ness: if data item x is in Rj, it is not in any other fragment ∀ x ∈ Ri,  ∃ Rj such that x ∈ Rj, i ≠ j Virtual University of Pakistan

  11. Allocation Strategy: Partitioned, fully or partially replicated; depends mainly on requirements Virtual University of Pakistan

  12. Horizontal Fragmentation Virtual University of Pakistan

  13. Partitions a table along its tuples • is performed based on some Predicate/ Condition Virtual University of Pakistan

  14. Primary Horizontal Fragmentation(PHF) Virtual University of Pakistan

  15. Information Requirements Virtual University of Pakistan

  16. Database Information: We may need to consult the conceptual DB design RDM being Semantically not that rich Apart from tables, we need relationships, cardinality and the owner and member tables Virtual University of Pakistan

  17. PAY title, sal owner = PAY member = EMP EMP eNo, Name, title jNo, jName, budget, loc PROJ eNo, jNo, resp, dur ASIGN Virtual University of Pakistan

  18. Application Requirement Virtual University of Pakistan

More Related