Database Management systems phần 2 doc

... 35.0 85 Art 3 25 .5 95 Bob 3 63.5 Figure 4.15 An Instance S3 of Sailors sid bid day 22 101 10/10/98 22 1 02 10/10/98 22 103 10/8/98 22 104 10/7/98 31 1 02 11/10/98 31 103 11/6/98 31 104 11/ 12/ 98 64 101 ... rating age 28 yuppy 9 35.0 31 Lubber 8 55.5 44 guppy 5 35.0 58 Rusty 10 35.0 Figure 4 .2 Instance S2 of Sailors sid bid day 22 101 10/10/96 58 103 11/ 12/ 96 Figure 4.3 Instance...

Ngày tải lên: 08/08/2014, 18:22

... equidepth, respectively. 10 11 12 13 140 2 31 56789410 11 12 13 140 2 31 567894 10 11 12 13 140 2 31 567894 10 11 12 13 140 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 ... that selections are commutative: σ c 1 (σ c 2 (R)) ≡ σ c 2 (σ c 1 (R)) In other words, we can test the conditions c 1 and c 2 in either or...

Ngày tải lên: 08/08/2014, 18:22

... 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), T2:R(Y) 5. T1:R(X), T2:W(X), ... T1:W(X), T2:Commit, T1:Abort 10. T2: R(X), T3:W(X), T3:Commit, T1:W(Y), T1:Commit, T2:R(Y), T2:W(Z), T2:Commit 11. T1:R(X), T2:W(X), T2:Commit, T1:W(X), T1:Commit, T3:R(X), T3:Commit 12. T1:R(...

Ngày tải lên: 08/08/2014, 18:22

... page 5. Database management systems - 2. Using a database for document retrieval - page 1 Information Management Resource Kit Module on Management of Electronic Documents UNIT 5. DATABASE MANAGEMENT ... database technology in several ways. Here you can look at three of these: Database Table metadata Table Text Documents Database Document Text Documents Document Meta Da...

Ngày tải lên: 31/03/2014, 20:20

... query language, host language, data sublanguage, database utility, catalog, client/ server architecture. 2. 2. Discuss the main categories of data models. 2. 3. What is the difference between a database schema and a database state? 2. 4. ... database systems and may provide a historical perspective for the interested reader. 1.7 A Brief History of Database Applications I21 1.7...

Ngày tải lên: 07/07/2014, 06:20

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Ngày tải lên: 26/01/2014, 17:20

... tính ( ) ( ) ( ) ( ) 11 0 12 DD zz zz K zzzz −− −− ( ) ( ) 2 0 120 12 12 0 1 2 1 0 DD DD zKzzzKzz zz K z z ⎡ ⎤ +−++ + ⎢ ⎥ ⎣ ⎦ ++ = () 2 22 rj zc z r−+= ()( ) () ( ) ()( ) 12 1 2 12 1 2 121 2 1 21 2 2 12 1 2 rj DD DD DD ... thứcquenbiếtsau: Ví dụ: chọn n = 2 (xấpxỉ bậc2) 0 12 12 2 2 12 0 21 20 2 ccc Tc Tc T cTc ++ = −− = += 01 2 321 ;; 22 ccc TT T − == =...

Ngày tải lên: 22/07/2014, 09:20

... Turbines & Engines Systems (304) 28 5-4603 alayne@netl.doe.gov Heather Quedenfeld National Energy Technology Laboratory Communications and Public Affairs Division (304) 28 5-5430 heather.quedenfeld@netl.doe.gov U.S. ... project. Each company contributes $25 ,000 (non-voting $7,500) a year to the program. " EPRI (non-voting) " General Electric Power " Honeywell Engine S...

Ngày tải lên: 08/08/2014, 11:21

... 320 12. 1.1 Access Paths 320 12. 1 .2 Preliminaries: Examples and Cost Calculations 321 12. 2 The Selection Operation 321 12. 2.1 No Index, Unsorted Data 322 12. 2 .2 No Index, Sorted Data 322 12. 2.3 ... 643 22 .1 .2 Databases and the Web 645 22 .2 Architecture 645 22 .2. 1 Application Servers and Server-Side Java 647 22 .3 Beyond HTML 651 22 .3.1 Introduction to XML 6 5...

Ngày tải lên: 08/08/2014, 18:22

... 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 of sailors who are both younger than 30 and older than 20 , we use the ... SELECT * FROM Sailors S2 WHERE S2.age < 21 AND S.rating <= S2.rating ) SELECT * FROM Sailors S WHERE S.rating > ANY ( SELECT S2.rating FROM Sailors S2 WHERE S2....

Ngày tải lên: 08/08/2014, 18:22