Database Management systems phần 1 potx

... 308 11 .3 Minimizing I/O Cost versus Number of I/Os 309 11 .3 .1 Blocked I/O 310 11 .3.2 Double Buffering 311 11 .4 Using B+ Trees for Sorting 312 11 .4 .1 Clustered Index 312 11 .4.2 Unclustered Index 313 11 .5 ... Replication 611 21. 8 Distributed Catalog Management 611 21. 8 .1 Naming Objects 612 21. 8.2 Catalog Structure 612 21. 8.3 Distributed Data Independence 613 2...

Ngày tải lên: 08/08/2014, 18:22

... Sailors sid bid day 22 10 1 10 /10 /98 22 10 2 10 /10 /98 22 10 3 10 /8/98 22 10 4 10 /7/98 31 102 11 /10 /98 31 103 11 /6/98 31 104 11 /12 /98 64 10 1 9/5/98 64 10 2 9/8/98 74 10 3 9/8/98 Figure 4 .16 An Instance R2 ... instances B1, R2, and S3 is shown in Figure 4.20. sname bid day Dustin 10 1 10 /10 /98 Dustin 10 2 10 /10 /98 Dustin 10 3 10 /8/98 Dustin 10 4 10...

Ngày tải lên: 08/08/2014, 18:22

... answer variable N, which must be a free variable, is handled: {N|∃I1,N1,T1,A1,I2,N2,T2,A2( I1,N1,T1,A1∈Sailors(A1 < 30 ∧N = N1) ∨I2,N2,T2,A2∈Sailors(A2 > 20 ∧ N = N2))} To print the names ... we could say < 10 to retrieve sailors with a rating less than 10 or say 10 to retrieve sailors whose rating is not equal to 10 . The expression 10 in an attribute column is thesameas=...

Ngày tải lên: 08/08/2014, 18:22

... B =17 B =12 9 B=257 10 0 7 4 3 2 1 1 1, 000 10 5 4 3 2 2 10 ,000 13 7 5 4 2 2 10 0,000 17 9 6 5 3 3 1, 000,000 20 10 7 5 3 3 10 ,000,000 23 12 8 6 4 3 10 0,000,000 26 14 9 7 4 4 1, 000,000,000 30 15 10 ... shown in Figure 10 .9, the appropriate bucket has space for the new data entry. The file after the insertion is shown in Figure 10 .10 . 10 h h 00 01 10 11 000 0 01...

Ngày tải lên: 08/08/2014, 18:22

... bucket. Figure 14 .4 shows two different kinds of histograms, called equiwidth and equidepth, respectively. 10 11 12 13 14 0 2 31 56789 410 11 12 13 14 0 2 31 567894 10 11 12 13 14 0 2 31 567894 10 11 12 13 14 0 2 31 ... 567894 10 11 12 13 14 0 2 31 567894 Equidepth 2.67 1. 33 5.0 1. 0 5.0 2.67 1. 33 5.0 1. 0 5.0 2.67 1. 33 5.0 1. 0 5.0 Equiwidth Bucket...

Ngày tải lên: 08/08/2014, 18:22

... than $10 0,000 and whose age is equal to their manager’s age. First, a nested query: SELECT E1.ename FROM Emp E1 WHERE E1.sal > 10 0 AND E1.age = ( SELECT E2.age FROM Emp E2, Dept D2 WHERE E1.dname ... Prove that the decom- position of R into R 1 and R 2 is lossless-join if and only if F + contains R 1 ∩ R 2 → R 1 or R 1 ∩ R 2 → R 2 . Exercise 15 .19 Prove that the optimization o...

Ngày tải lên: 08/08/2014, 18:22

... T1:R(X), T2:W(X), T1:W(X), T2:Abort, T1:Commit 6. T1:R(X), T2:W(X), T1:W(X), T2:Commit, T1:Commit 7. T1:W(X), T2:R(X), T1:W(X), T2:Abort, T1:Commit 8. T1:W(X), T2:R(X), T1:W(X), T2:Commit, T1:Commit 9. ... actions. 1. T1:R(X), T2:R(X), T1:W(X), T2:W(X) 2. T1:W(X), T2:R(Y), T1:R(Y), T2:R(X) 3. T1:R(X), T2:R(Y), T3:W(X), T2:R(X), T1:R(Y) 4. T1:R(X), T1:R(Y), T1:W(X), T2:R(Y), T3:W(Y), T1:W(X),...

Ngày tải lên: 08/08/2014, 18:22

... page 1 has hyperlinks to pages 5 and 6. Internet Databases 665 Rid Document Signature 1 agent James Bond 11 00 2 agent mobile computer 11 01 3 James Madison movie 10 11 4 James Bond movie 11 10 Word ... Hash agent 1, 2 10 00 Bond 1, 4 010 0 computer 2 010 0 James 1, 3, 4 10 00 Madison 3 00 01 mobile 2 00 01 movie 3, 4 0 010 Figure 22.9 A Text Database with Four Rec...

Ngày tải lên: 08/08/2014, 18:22

... equal Object -Database Systems 737 We will use acronyms for relational database management systems (RDBMS), object- oriented database management systems (OODBMS), and object-relational database management ... shown in Figure 24 .1. The first partition consists of the two transactions with transid 11 1 and 11 2, the second partition consists of the two transactions with tra...

Ngày tải lên: 08/08/2014, 18:22

... Statistical database design. ACM Transactions on Database Systems, 6 (1) :11 3 13 9, 19 81. [14 9] J. Chomicki. Real-time integrity constraints. In ACM Symp. on Principles of Database Systems, 19 92. Design ... on Database Systems, 12 (4):566–592, 19 87. [504] Z. Ozsoyoglu and L Y. Yuan. A new normal form for nested relations. ACM Transac- tions on Database Systems, 12 (1...

Ngày tải lên: 08/08/2014, 18:22