13.1 through 13.5, 13.10 and 13.11

More documents

Recommendations

Info

Chapter 13 Disk Storage, Basic File Structures, and HashingBlock 1Name Ssn Birth date Job Salary SexAaron, EdAbbott, DianeAcosta, MarcBlock 2Adams, JohnAdams, RobinAkers, JanBlock 3Alexander, EdAlfred, BobAllen, SamBlock 4Allen, TroyAnders, KeithAnderson, RobBlock 5Anderson, ZachAngeli, JoeArcher. SueBlock 6Arnold, MackArnold, StevenAtkins, TimothyBlock n-1Wong, JamesWood, DonaldWoods, MannyBlock nWrioht, PamWvatt, CharlesZimmer, ByronFigure 13.7Some blocks of an ordered (sequential) file of EMPLOYEErecords wrth Name as the orderino kev field.
13.7 Files of Ordered Records (Sorted Files)faster access rvhen the binary searcl-r technique is used, which constitutes an improvementover linear searches, although it is not often used for disk files.A binary search for disk files can be done on the blocks rather than on the records.Suppose that the file has b blocks numbered 1,2,..., b; the records are ordered byascending value of their ordering key field; and we are searchir.rg for a record whoseordering key field vah-re is K. Assunring that disk addresses of the flle blocks are availabiein the file header, the bir-rary search c:rn be described by Algorithm l 3. 1 . A binarysearch usually accesses log,(b) blocks, whether the record is found or not-animprovement over linear searches, rvhere, on the average, (lrl2) blocks are accessedwhen the record is found and b blocks are accessed when the record is not found.Algorithm 13.1. Binary Search on an Ordering Key of a Disk FileI
Page 1 and 2: -\,--{+.nupt",. 1 3Disk StoragG, Ba
Page 3 and 4: 13.1 Introduction!( ) frl \.i()tl t
Page 5 and 6: 13.2 Secondarv Storaoe Devices467to
Page 7 and 8: 13.2 Secondary Storage Devicesi\ (r
Page 9 and 10: 13.2 Secondary Storage Devices 471T
Page 11 and 12: 13.3 Buffering of Blocks473r-e' and
Page 13 and 14: 13.4 Placinq File Records on Disk47
Page 15 and 16: 13.4 Placino File Records on Disk 4
Page 17 and 18: engtht."IIInumber of records per bl
Page 19 and 20: 13.5 Ooerations on Files481artment.
Page 21: I3.7 Files of Ordered Records (Sort
Page 25 and 26: 13.8 Hashino Techniouesn eachcbleme
Page 27 and 28: 13.8 Hashing TechniquesOther hashin
Page 29 and 30: 13.8 Hashing Techniques 491s mayMai
Page 31 and 32: 'l 3.8 Hashing Techniquesute theNew
Page 33 and 34: 13.9 Other Primarv File Oroanizatio
Page 35 and 36: 13.10 Parallelizing Disk Access Usi
Page 37 and 38: 13. 10 Parallelizing Disk Access Us
Page 39 and 40: ,l|{l}'qn--*13.11 Storaoe Area Netw
Page 41 and 42: Review Ouestions. it has)ntoa'qulre

13.1 through 13.5, 13.10 and 13.11

Create successful ePaper yourself

Delete template?

Save as template?