Chapter 5 Database and Data Warehouse

Chapter 5 Database and Data Warehouse Unit 1 An Introduction to Database

数据库系统的发展 第一个数据库系统诞生于20世纪60年代，其后，人们不断地开发数据模型（Data model），依次出现了表模型（Table/flat model）、层次模型（Hierarchical model）、网络模型（Network model）、关系模型（Relational model）和对象数据库模型（Object database model）。

Vocabulary • flat/table model 平面/表模型 • hierarchical model层次模型 • network model网络模型 • relational model 关系模型 • DB (Database) 数据库 • DBMS (Database Management System)数据库管理系统

Vocabulary • dimension 维度 • two-dimensional 二维的 • array 数组 • data element数据元素 • column列 • row行 • character 字符 • integer整数 • floating point number 浮点数

Vocabulary • spreadsheet 电子表格 • pointer 指针 • reference引用，参考 • directed graph 有向图 • undirected graph 无向图 • data structure数据结构 • operator操作符 • relational algebra关系代数 • calculus 微积分

Vocabulary • constraint n. 约束 • integrity constraints 完整性约束更新数据库时，表中不能出现不符合完整性要求的记录，以保证为用户提供正确、有效的数据。三种完整性约束：1、实体完整性2、参照完整性3、用户自定义完整性

Vocabulary • domain 域 • attribute 属性 • principle原理 • query n.查询(操作) v. 查询 • mathematical 数学的 • index n.索引 v.索引 • sort n.排序 v.排序

Vocabulary • hash 散列表或哈希表，用于提高查询速度的一种数据结构。 • linked list链表 • map v. 映射，映象 • SQL (Structured Query Language)结构化查询语言 • polymorphism多态性 • search engine搜索引擎

Text 第2自然段第4行补充： Historically, the hierarchical model was first achieved, followed by the network model, the relational model overcame with the so-called flat model accompanying it for low-end usage.

Answer the following questions according to paragraph 2 • How to classify database? • How many types can database models be classified into? What are they? • Is flat model more advanced than relational model?

Answer the following questions according to paragraph 2 • How to classify database? Answer: Use programming model associated with database to classify them.

Answer the following questions according to paragraph 2 2. How many types can database models be classified into? What are they? Answer: There are four types of database model: flat model, hierarchical model, network model and relational model.

Answer the following questions according to paragraph 2 3. Is flat model more advanced than relational model? Answer: NO. “the relational model overcame with the so-called flat model accompanying it for low-end usage.”

Text They were never theorized and were deemed as data models only as a contrast to the relational model, not having conceptual underpinnings of their own; they have arisen simply out of the realization of physical constraints and programming, not data models. Question: what does the word “they” refer to? They: hierarchical model; network model; flat model

Text They were never theorized. They were deemed as data models only as a contrast to the relational model, not having conceptual underpinnings of their own.

Text They were never theorized. v. 理论化它们从没得到理论化。

Text They were deemed as data models only as a contrast to the relational model, not having conceptualunderpinnings of their own. deem：认为be deemed as : 把…视为… contrast：n. 对比 conceptual:adj.概念的 underpinning：n. 基础，基础材料 not having conceptual underpinnings of their own: 作为表示原因的状语，“它们没有自己的概念基础” They were deemed as data models only as a contrast to the relational model：它们只有在与关系模型相比较时，才被视为数据模型。

Text They were deemed as data models only as a contrast to the relational model, not having conceptual underpinnings of their own. 由于它们没有自己的概念基础，它们只有在与关系模型相比较时，才被视为数据模型。

Text They were never theorized and were deemed as data models only as a contrast to the relational model, not having conceptual underpinnings of their own; they have arisen simply out of the realization of physical constraints and programming, not data models.

Text They have arisen simply out of the realization of physical constraints and programming, not data models. arise：v. 上升，出现 realization: n. 实现 physical：adj. 物理的 constraint: n. 约束 the realization of physical constraints and programming：物理约束及编程的实现

Text They have arisen simply out of the realization of physical constraints and programming, not data models. 它们只是简单地从物理约束及编程的实现中出现，而非数据模型。

Answer the following question according to paragraph 3 The following table records a set of attributes from a book information flat model, for each attribute or column, choose an adaptable data type. (1) (2) (3) (4) (5) (6)

Answer the following question according to paragraph 3 (1) (2) (3) (4) (5) (6) • Integer (2) character (3) character • (4) character (5) date • (6)floating point number

Network Model Network model’s feature is that the schema, viewed as a graph in which object types are nodes and relationship types are arcs.

Relational Model Translate the first paragraph in page 131.

Read the second paragraph in page 131. According to the concept of each database model, which two models have pointers? Answer: hierarchical model and network model

Text As a result, relational databases can be used by multiple applications in ways (which) the original designers did not foresee, which is especially important for databases that might be used for decades.

Text As a result, relational databases can be used by multiple applications in ways(which) the original designers did not foresee, which is especially important for databases that might be used for decades.

Text relational databases can be used by multiple applications in ...(修饰词)… ways relational databases can be used by multiple applications: 关系数据库能被多个程序使用 in … ways：以…方式关系数据库可以以…方式被多个程序使用。

Text relational databases can be used by multiple applications in ways (which)the original designers did not foresee original: 原始的，初始的 original designer -》 database designer foresee:预见，预见到 (which)the original designers did not foresee：数据库设计者没有预见到的 ways (which) the original designers did not foresee：数据库设计者没有预见到的方式

Text relational databases can be used by multiple applications in ways (which) the original designers did not foresee. 关系数据库可以以数据库设计者没有预见到的方式被多个程序使用。

Text As a result, relational databases can be used by multiple applications in ways (which) the original designers did not foresee, whichis especially important for databases that might be used for decades. which --> > relational databases can be used by multiple applications in ways (which) the original designers did not foresee “which”指的是关系数据库的这种性质：“关系数据库可以以数据库设计者没有预见到的方式被多个程序使用。”

Text As a result, relational databases can be used by multiple applications in ways (which) the original designers did not foresee, which is especially important for databases that might be used for decades.

which is especially important for databases that might be used for decades is especially important for databases：对数据库来说是十分重要的 database that might be used for decades: 可能被用上数十年的数据库 which is especially important for databases that might be used for decades：对可能被用上数十年的数据库来说是十分重要的

As a result, relational databases can be used by multiple applications in ways (which) the original designers did not foresee, whichis especially important for databases that might be used for decades. 因此，关系数据库可以以数据库设计者没有预见到的方式被多个程序使用，这对于可能被用上数十年的数据库来说是十分重要的。

Fill in the blanks with the following words A. query B. database C. DBMS D. accessing E. interface The system software package that handles the difficult tasks associated with creating, __(1)_, and maintaining database records is called _(2). It establishes an _(3)_ between the database itself and the users of the database. It can organize, process and present selected data elements from the _(4)_. This capability enables decision makers to search and _(5)__ database contents in order to find answers to unplanned questions.

Implementations and Indexing Read the first paragraph in this section and fill in the blanks with the following words in proper form. A. row B. pointer C. content D. index E. query D. table • Indexing is a way to increase the _(1)_ speed in a database. The function of index is just like a _(2)_ in a book. If you want to find certain records in a _(3)_,_(4)_ can help you quickly navigate to the _(5)_ that match the values you specify, because it associates the _(6)_ in it with those values.

Chapter 5 Database and Data Warehouse