vnz 0233 databases demystified - a self-teaching guide (2004)

... I’ve heard the term “data bank” used. What is the difference between a data bank and a database? A: A data bank and a database are the same thing. Data bank is merely an older term that was used ... Layer Database File Database File Database File Database File Database File Figure 1-1 Database layers of abstraction Chapter 1: Database Fundamentals 5 make a distinction? A n...

Ngày tải lên: 25/12/2013, 16:15

... both specialize in their comparative advantage, the amount of soda and pizza available to both of them is greater than if they each produced both soda and pizza. If Sandy and Robinson agree on ... Robinson and Sandy can produce 50 pizzas and 30 sodas and can split this combination of pizza and sodas in a mutually benefi cial way so that each of them can consume more pizza and soda than...

Ngày tải lên: 08/03/2014, 10:20

... on a diet that is either all corn silage or predominately a concentrate of corn grain and alfalfa pellets than on a diet that is half silage and half concentrate (Bhide et al. 1984). However, any ... What happens to the demand for baseball bats? 8. Suppose some raptors escape from Jurassic Park, multiply in the wild, and eat a large number of goats and chickens on nearby farms. a. Wh...

Ngày tải lên: 08/03/2014, 10:20

... causes a change in phase of the working substance. EXAMPLE 4.11 Steam enters a throttling valve at 8000 kPa and 300°C and leaves at a pressure of 2000 kPa. Determine the fi nal temperature and ... Thermodynamics Demystifi ed 4 Thermodynamics Demystifi ed 1.3 Properties and State of a System The matter in a system may exist in several phases: a solid, a liquid, or a gas....

Ngày tải lên: 08/04/2014, 11:43

... Database Design Using Normalization 14 5 The Need for Normalization 14 7 Insert Anomaly 14 8 Delete Anomaly 14 8 Update Anomaly 14 8 Applying the Normalization Process 14 8 Choosing a Primary Key 15 1 First ... databases, including properties common to databases, prevalent database models, a brief his - tory of databases, and the rationale for focusing on the relational model....

Ngày tải lên: 08/08/2014, 18:22

... screen CHAPTER 2 Exploring Relational Database Components 33 Demystified / Databases Demystified / Oppel/ 22 5364-9 / Chapter 2 Logical/Physical Database Design Components The logical database design ... Deleting database objects c. Adding new database objects d. Adding data items to existing database objects e. Deleting data items from existing database objects CHAPTER 1 Database...

Ngày tải lên: 08/08/2014, 18:22

... row are called aggregate functions. The following table shows aggregate functions that are commonly used in relational databases: Function Name Description AVG Calculates the average value for a ... printer profile Composite Default screen 78 Databases Demystified Demystified / Databases Demystified / Oppel/ 22 536 4-9 / Chapter 3 beauty of relational databases is that we nee...

Ngày tải lên: 08/08/2014, 18:22

... that ends every SQL statement. In Oracle, a transaction is automatically started for each database user session as soon as the user connects to the database. At any time, the database user can ... table’s data. The ALTER TABLE Statement The ALTER TABLE statement may be used to change many aspects of the definition of a database table. Again, there is a wide variation in implementation a...

Ngày tải lên: 08/08/2014, 18:22

... redundant data in tables ã Storing summarized data in tables Note also that normalization is intended to remove anomalies from databases that are used for online transaction-processing systems. Databases ... Databases that store historical data used solely for analytical purposes are not as subject to insert, update, and de - lete anomalies. Chapter 12 contains more information on data...

Ngày tải lên: 08/08/2014, 18:22

... profile Composite Default screen 194 Databases Demystified Demystified / Databases Demystified / Oppel/ 225 364 -9 / Chapter 7 The Data Flow Diagram The data flow diagram (DFD) is the most data centric of all ... privileges. 6. The update anomaly refers to a situation where: a. A simple update requires updates to multiple rows of data. b. Data cannot be updated because it does...

Ngày tải lên: 08/08/2014, 18:22

... considered a best practice because it can lead to a lack of data sharing. Moreover, placing geographic or organizational unit names in table names plays havoc every time the organization changes. CHAPTER ... synchronizing data updates for any redundantly stored data ã More expensive than the centralized model ã Lack of guidelines and best practices for how to partition data and applicatio...

Ngày tải lên: 08/08/2014, 18:22

... even to a different version of the same vendor’s database). Connecting Databases to Java Applications Java started as a proprietary programming language (originally named Oak) that was developed ... that binds the API to the particular database and platform, and a definition known as the ODBC data source contains the information necessary for a particular application to connect with...

Ngày tải lên: 08/08/2014, 18:22

... Default screen CHAPTER 12 Databases for Online Analytical Processing 301 Demystified / Databases Demystified / Oppel/ 225364 -9 / Chapter 12 Data Marts A data mart is a subset of a data warehouse ... contains more data than a data warehouse. e. The project has a lower overall cost than a data warehouse project. 16. Building a data warehouse first, followed by data mart...

Ngày tải lên: 08/08/2014, 18:22

... letter A in the acronym ACID stands for: a. Automated b. Abbreviated c. Atomicity d. Autonomous e. Analog 82. Database locks: a. Are implemented in exactly the same way by all major database vendors b. ... 261 models, database, 2 modules, 55 MOLAP databases, 299–301 msdb database, 261 multidimensional OLAP databases, 299–301 multiple joins, 77–80 multivalued attributes, 150 N namespace,...

Ngày tải lên: 08/08/2014, 18:22

... databases, prevalent database models, a brief his - tory of databases, and the rationale for focusing on the relational model. Properties of a Database A database is a collection of interrelated ... Access places the entire database in a single data file, so an Access database can be defined as the file that contains the data items. Oracle Corporation defines their database as...

Ngày tải lên: 20/10/2014, 01:12