Database Management systems phần 7 doc

... entry 40*. 5. Insert data entries 62* and 75 *. Exercise 19.11 Consider a database that is organized in terms of the following hierarachy of objects: The database itself is an object (D), and it ... algorithm: Write-ahead logging: Any change to a database object is first recorded in the log; the record in the log must be written to stable storage before the change to the database obje...

Ngày tải lên: 08/08/2014, 18:22

... 4.15, 4.16, and 4. 17, respectively. sid sname rating age 22 Dustin 7 45.0 29 Brutus 1 33.0 31 Lubber 8 55.5 32 Andy 8 25.5 58 Rusty 10 35.0 64 Horatio 7 35.0 71 Zorba 10 16.0 74 Horatio 9 35.0 85 ... the most widely used commercial relational database language. It was originally developed at IBM in the SEQUEL-XRM and System-R projects (1 974 –1 977 ). Almost immediately, other vend...

Ngày tải lên: 08/08/2014, 18:22

... equidepth, respectively. 10 11 12 13 140 2 31 5 678 9410 11 12 13 140 2 31 5 678 94 10 11 12 13 140 2 31 5 678 94 10 11 12 13 140 2 31 5 678 94 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 ... Real systems vary in their catalog schema design, but the catalog is always implemented as a collection of relations, and it essentially describes...

Ngày tải lên: 08/08/2014, 18:22

... 5 Phân tích thống kê thông tin và áp dụng thông tin. CHƯƠNG 7 QUẢN TRỊ CHẤT LƯỢNG ĐỒNG BỘ (Total Quality Management – TQM) (Phần 7) V KIỂM TRA HỆ THỐNG CHẤT LƯỢNG 5.1 Mục đích của việc đánh

Ngày tải lên: 01/07/2014, 08:39

... (GHz) -15 -10 -5 0 5 10 15 62.5 67. 5 72 .5 77 .5 82.5 (a) (b) Frequency Shift (GHz) -20 -10 0 -20 -10 0 10 20 -30 Optical Power (dB) Temperature ( o C) Frequency Shift (GHz) -15 -10 -5 0 5 10 15 62.5 67. 5 72 .5 77 .5 82.5 (a) (b) ... cellular mobile communication systems, ” Computer Networks and ISDN Systems, vol. 20, pp. 4 47- 454, 1990. [55] M. Berg, S. Pettersson, and J. Zander,...

Ngày tải lên: 06/08/2014, 00:21

... 201 7. 2.3 Levels of Redundancy 203 7. 2.4 Choice of RAID Levels 206 7. 3 Disk Space Management 2 07 7.3.1 Keeping Track of Free Blocks 2 07 7.3.2 Using OS File Systems to Manage Disk Space 2 07 7.4 ... Queries 70 0 23.6.2 Online Aggregation 70 1 23 .7 Points to Review 70 2 24 DATA MINING 70 7 24.1 Introduction to Data Mining 70 7 24.2 Counting Co-occurrences 70 8 24.2.1 Freq...

Ngày tải lên: 08/08/2014, 18:22

... detail in this chapter. Section 7. 1 introduces disks and tapes. Section 7. 2 describes RAID disk systems. Section 7. 3 discusses how a DBMS manages disk space, and Section 7. 4 explains how a DBMS fetches ... the block. 208 Chapter 7 instructions: “Read block m of track t of cylinder c of disk d.” A database disk space manager could be built using OS files. For example, the entire d...

Ngày tải lên: 08/08/2014, 18:22

... than 2 57 buffers, but this table illustrates the importance of a high fan-in during merging. N B=3 B=5 B=9 B= 17 B=129 B=2 57 100 7 4 3 2 1 1 1,000 10 5 4 3 2 2 10,000 13 7 5 4 2 2 100,000 17 9 6 ... 16* 135 17* 18* 20* 17 20 22 33* 34* 38* 39* 30 22* 27* 29*21* 7* 5* 8* 3*2* Figure 9.20 A B+ Tree during a Deletion In contrast to the case when we deleted 24* from the tree of Figur...

Ngày tải lên: 08/08/2014, 18:22

... database design. How do you see Designview being used, if at all, in the context of physical database design? BIBLIOGRAPHIC NOTES [ 572 ] is an early discussion of physical database design. [ 573 ] ... retrieved in this case than with an index on age, sal. 16 .7 OVERVIEW OF DATABASE TUNING After the initial phase of database design, actual use of the database provides a valuabl...

Ngày tải lên: 08/08/2014, 18:22

... and recovery in distributed systems. [82] contains several articles on these topics. Multidatabase systems are discussed in [7, 96, 193, 194, 205, 412, 420, 451, 452, 522, 558, 672 , 6 97] ; see [95, 421, ... Web. Exercise 22.6 Assume you are given a document database that contains six documents. After stemming, the documents contain the following terms: Document Terms 1 car manufacturer...

Ngày tải lên: 08/08/2014, 18:22