数据库英文解释
数据库(中英文翻译)
原文：Planning the DatabaseIt is important to plan how the logical storage structure of the database will affect system performance and various database management operations. For example, before creating any tablespaces for your database, you should know how many data files will make up the tablespace,what type of information will be stored in each tablespace, and on which disk drives the datafiles will be physically stored. When planning the overall logical storage of the database structure, take into account the effects that this structure will have when the database is actually created and running.You may have database objects that have special storage requirements dueto type or size.In distributed database environments, this planning stage is extremely important. The physical location of frequently accessed data dramatically affects application performance.During the planning stage, develop a backup strategy for the database. You can alter the logical storage structure or design of the database to improve backup efficiency. Backup strategies are introduced in a later lesson.These are the types of questions and considerations, which you will encounter as a DBA, and this course (in its entirety) is designed to help you answer them.Databases: ExamplesDifferent types of databases have their own specific instance and storage requirements. YourOracle database software includes templates for the creation of these different types of databases.Characteristics of these examples are the following:• Data Warehouse: Store data for long periods and retrieve them in read operations.• Transaction Processing: Accommodate many, but usually small, transactions.• General Purpose: Work with transactions and store them for a medium length of time.Database Configuration Assistant (DBCA)You can use the Database Configuration Assistant (DBCA) to create, change the configuration of, or delete a database. You can also create a database from a list of predefined templates or use an existing database as a sample to create a new database or template. This is sometimes referred to as “database cloning.”You can invoke the DBCA by performing the following steps:1. Log on to your computer as a member of the administrative group that is authorized to install the Oracle software.2. If required, set environment variables.3. Enter dbca to invoke the DBCA.4. Click Next to continue.DBCA offers you a choice of assisting with several operations, for example, creating a database.Using the DBCA to Create a DatabaseYou can use the DBCA to create a database as follows:1. Select Create a Database on the DBCA Operations page to invoke a wizard that enables you to configure and create a database.The wizard prompts you to provide configuration information as outlined in the steps that follow. On most pages, the wizard provides a default setting that you can accept.2. Select the type of database template to be used in creating the database. There aretemplates for Data Warehouse, General Purpose, and Transaction Processing databases that copy a preconfigured database, including data files. These data files include control files,redo log files, and data files for various included tablespaces.Click Show Details to see the configuration for each type of database.For more complex environments, you may want to select the Custom Database option. Password ManagementAfter the DBCA finishes, note the following information for future reference:• Location of installation log files (see A)• Global database name (see B)• System identifier (SID) (see B)• Server parameter file name and location (see B)• Enterpr ise Manager URL (see C)Click Password Management to unlock database accounts that you plan to use.Provide apassword when you unlock an account.Creating a Database Design TemplateA template is a predefined database definition that you use as a starting point for a new database.If you do not create a template as part of the database creation process, you can do it anytime by invoking the DBCA. You have three ways to create a template: • From an existing template• From an existing database (structure only)• From an existing database (structure as well as data)The DBCA guides you through the steps to create a database design template.Using the DBCA to Delete a DatabaseTo delete (or configure) a database in UNIX or Linux, you must set ORACLE_SID in the shell from which DBCA is launched. Start the DBCA by entering dbca in a terminal window, and click Next on the Welcome page. To delete the database, perform the following steps:1. On the Operations page, select Delete a Database, and click Next.2. Select the database that you want to delete (in class, hist), and click Finish.3. Click Yes to confirm your deletion.Using the DBCA to Delete a Database (continued)Dropping a database involves removing its data files, redo log files, control files, and initialization parameter files. The DROP DATABASE statement deletes all control files and all other database files listed in the control file. To use the DROP DATABASE statement successfully,all the following conditions must apply:The database must be mounted and closed.The database must be mounted exclusively—not in shared mode.The database must be mounted as RESTRICTED.An example of this statement is:DROP DATABASE;The DROP DATABASE statement has no effect on archived log files nor does it have any effect on copies or backups of the database. It is best to use Recovery Manager (RMAN) to delete such files. If the database is on raw disks, then the actual raw disk special files are not deleted.Management FrameworkThere are three major components of the Oracle database management framework: • The database instance that is being managed• A listener that allows connections to the database• The management interface. This may be either a management agent running onthe database server (which connects it to Oracle Enterprise Manager Grid Control) or the stand-alone Oracle Enterprise Manager Database Control. This is also referred to as Database Console.Each of these components must be explicitly started before you can use the services of the component and must be shut down cleanly when shutting down the server hosting the Oracle database.The first component to be started is the management interface. After this is activated, the management interface can be used to start the other components. Starting and Stopping Database ControlOracle provides a stand-alone management console called Database Control for databases that are not connected to the Grid Control framework. Each database that is managed with Database Control has a separate Database Control installation, and from any one Database Control, you can manage only one database. Before using Database Control, ensure that a dbconsole process is started.To start the dbconsole process, use the following command:emctl start dbconsole To stop the dbconsole process, use the following command:emctl stop dbconsole To view the status of the dbconsole process, use the following command:emctl status dbconsole.Note: You may need to navigate to your $ORACLE_HOME/bin directory if this directory is not in your operating system (OS) path.Database Control uses a server-side agent process. This agent process automatically starts and stops when the dbconsole process is started or stopped.译文：规划数据库规划如何对数据库的逻辑存储结构将影响系统的性能和各种数据库管理操作是非常重要的。
(完整版)数据库重要术语(中英文)
单词汇总(数据库专业一点的词汇其实主要就是每章后面review items的内容,在这里简单列一下,如果你实在没时间看书,至少这些单词要熟悉.)：1. 数据库系统：database system(DS),database management system(DBMS)2.数据库系统(DS),数据库治理系统(DBMS )3. 关系和关系数据库table= relation , column = attribute 属性,domain, atomic domain, row= tuple ,relational database, relation schema, relation instance, database schema, database instance;4.表=关系,列=属性属性,域,原子域,排二元组,关系型数据库,关系模式,关系实例,数据库模式,数据库实例；1. key 们：super key, candidate key, primary key, foreign key, referencing relation, referenced relation;2.超码,候选码,主码,外码,参照关系,被参照关系5.关系代数(relational algebra): selection, project, natural join, Cartesian product, set operations, union, intersect, set difference( except\minus), Rename, assignment, outer join, grouping, tuple relation calculus6.(关系代数)：选择,工程,自然连接,笛卡尔积,集合运算,集,交集,集合差(除负),重命名,分配,外连接,分组,元组关系演算7.sql组成：DDL ：数据库模式定义语言,关键字：createDML ：数据操纵语言,关键字：Insert > delete、updateDCL ：数据库限制语言,关键字：grant、removeDQL ：数据库查询语言,关键字：select8.3.SQL 语言：DDL , DML , DCL , QL , sql query structure, aggregate functions, nested subqueries, exists(as an operator), unique(as anoperator), scalar subquery, assertion, index(indices), catalogs, authorization, all privileges, granting, revoking , grant option, trigger, stored procedure, stored function4.SQL语言：DDL , DML , DCL , QL , SQL查询结构,聚合函数,嵌套子查询,存在(如运营商),独特的(如运营商),标量子查询,断言指数(指数),目录,授权,所有权限,授予,撤销,GRANT OPTION ,触发器,存储过程,存储函数9. 表结构相关：Integrity constraints, domain constraints, referential integrity constraints10.完整性约束,域名约束,参照完整性约束5.数据库设计(ER 模型)：Entity-Relationship data model, ER diagram, composite attribute, single-valued and multivalued attribute,derived attribute, binary relationship set, degree of relationship set, mapping cardinality, 1-1, 1-m, m-n relationship set (one to one, one to many, many to many), participation, partial or total participation, weak entity sets, discriminator attributes, specialization and generalization6.实体关系数据模型,ER图,复合属性,单值和多值属性,派生属性,二元关系集,关系集,映射基数的程度,1-1, 1-米,MN关系集合(一对一,一对多,多对多),参与局部或全部参与,弱实体集,分辨符属性,特化和概化11. 函数依赖理论：functional dependence, normalization, lossless join (or lossless) decomposition,First Normal Form (1NF), the third normal form (3NF), Boyce-codd normal form (BCNF), R satisfies F, F holds on R, Dependency preservation 保持依赖,Trivial, closure of a set of functional dependencies 函数依赖集的闭包,closure of a set of attributes 属性集闭包,Armstrong 's axioms Armstrong 公理,reflexivity rule 自反律,augmentation rule,增广率, transitivity 传递律,restriction of F to R i F 在Ri 上的限定,canonical cover 正那么覆盖, extraneous attributes 无关属性,decomposition algorithm 分解算法.7.函数依赖,标准化,无损连接〔或无损〕分解,第一范式〔1NF〕,第三范式〔3NF〕 BC范式〔BCNF〕, R满足F, F持有R,依赖保存,平凡,一组函数依赖封闭,一组属性,8. 事务：transition, ACID properties ACID特性,并发限制系统concurrency control system,故障恢复系统recovery system,事务状态transition state,活动的active,局部提交的partiallycommitted,失败的failed,中止的aborted,提交的committed,已结束的terminated,调度schedule,操作冲突conflict of operations, 冲突等价conflict equivalence,冲突可串彳f化conflictserializablity ,可串行化顺序serializablity order,联级回滚cascading rollback,封锁协议lockingprotocol ,共享〔S〕锁shared-mode lock 〔S-lock〕,排他〔X〕锁exclusive -mode lock 〔X-lock〕, 相容卜i compatibility,两阶段封锁协议2-phase locking protocol,意向锁intention lock,时间戳timestamp, 恢复机制recovery scheme,日志log, 基于日志的恢复log-based recovery, 延迟的修改deferredmodification,立即的修改immediate modification,检查点checkpoint.数据库系统DBS Database System数据库系统应用Database system applications文件处理系统file-processing system数据不一致性data inconsistency——致性约束consistency constraint数据抽象Data Abstraction实例instance模式schema物理模式physical schema逻辑模式logical schema物理数据独立性physical data independence数据方^型data model实体-联系模型entity-relationship model 〔E-R〕关系数据模型relational data model基于对象的数据模型object-based data model半结构化数据模型semistructured data model数据库语言database language数据定义语言data-definition language数据操纵语言data-manipulation language查询语言query language元数据metadata应用程序application program标准化normalization数据字典data dictionary存储治理器storage manager查询治理器query processor事务transaction原子性atomicity故障恢复failure recovery并发限制concurrency-control两层和三层数据库体系结构two-tier/three-tier数据才2掘data mining数据库治理员DBA database administrator表table关系relation元组tuple空值null value数据库模式database schema数据库实例database instance关系模式relation schema关系实例relation instance码keys超码super key候选码candidate key主码primary key外码foreign key参照关系referencing relation被参照关系referenced relation属性attribute域domain原子域atomic domain参照完整性约束referential integrity constraint模式图schema diagram查询语言query language过程化语言procedural language非过程化语言nonprocedural language关系运算operations on relations选择元组selection of tuples选择属性selection of attributes自然连接natural join笛卡尔积Cartesian product集合运算set operations关系代数relational algebraSQL 查询语言SQL query structureSelect 字句select clauseFrom 字句from clauseWhere 字句where clause自然连接运算natural join operationAs 字句as clauseOrder by 字句order by clause相关名称 (相关变量,元组变量) correlation name (correlation variable , tuple variable ) 集合运算set operationsUnionInterestExcept空值null values真值"unknown " truth “ unknown 〞聚集函数aggregate functionsavg, min, max, sum, countgroup byhaving嵌套子查询nested subqueries集合比拟set comparisons{ «,? 二 ,〉〉,?=}{some , all}existsuniquelateral 字句lateral clausewith 字句with clause标量子查询scalar subquery数据库彳修改database modification删除deletion插入insertion更新updating参照完整性referential integrity参照完整T约束referential Hntegrity constraint 或子集依赖subset dependency 可延迟的deferrable断言assertion连接类型join types内连接和夕卜连接inner and outer join左外连接、右外连接和全外连接left、right and full outer joinNatural连接条件、using连接条件和on连接条件natural using and so on 视图定义view definition物化视图materialized views视图更新view update事务transactions提交commit work回滚roll back work原子事务atomic transaction完整性约束integrity constraints域约束domain constraints唯——性约束unique constraintCheck 字句check clause参照完整性referential integrity级联删除cascading delete级联更新cascading updates断言assertions日期和时间类型date and time types默认值default values索弓I index大对象large object用户定义类型user-defined types域domains目录catalogs模式schemas授权authorization权卜M privileges选择select插入insert更新update所有权限all privileges授予权卜M granting of privileges收回权卜M revoking of privileges授予权限的权限privileges to privilegesGrant option角色roles视图授权authorization on views执行授权execute authorization调用者权限invoker privileges行级授权row-level authorizationJDBCODBC预备语句prepared statements 访问元数据accessing metadata SQL 注入SQL injection 嵌入式SQL embedded SQL 游标cursors 可更新的游标updatable cursors 动态SQL dynamic SQL SQL 函数SQL functions 存储过程stored procedures 过程化结构procedural constructs夕卜部语言例程external language routines触发器triggerBefore 和after 触发器before and after triggers过渡变量和过渡表transition variables and tables递归查询recursive queries单调查询monotonic queries排名函数ranking functionsRankDense rankPartition by分窗windowing联机分析处理〔OLAP 〕 online analytical processing多维数据multidimensional data度量属性measure attributes维属性dimension attributes转轴pivoting数据立方体data cube切片和切块slicing and dicing上卷和下钻rollup and drill down交叉表cross-tabulation第七章实体-联系数据模型Entity-relationship data model实体和实体集entity and entity set属性attribute域domain简单和复合属T生simple and composite attributes单值和多值属T生single-valued and multivalued attributes空值null value派生属性derived attribute超码、候选码以及主码super key ,candidate key, and primary key联系和联系集relationship and relationship set二元联系集binary relationship set联系集的度degree of relationship set描述性属性descriptive attributes超码、候选码以及主码super key ,candidate key, and primary key角色role自环联系集recursive relationship setE-R 图E-R diagram映射基数mapping cardinality——对——联系one-to-one relationship——对多联系one-to-many relationship多对——联系many-to-one relationship多对多联系many-to-many relationship参与participation全部参与total participation局部参与partial participation弱实体集和强实体集weak entity sets and strong entity sets分辨符属性discriminator attributes标识联系identifying relationship特化和概化specialization and generalization超类和子类superclass and subclass属性继承attribute inheritance单和多继承single and multiple inheritance条件定义的和用户定义的成员资格condition-defined and userdefined membership 不相交概化和重叠概化disjoint and overlapping generalization全部概化和局部概化total and partial generalization聚集aggregationUMLUML 类图UML class diagram第八章E-R 模型和标准化E-R model and normalization分解decomposition函数依赖functional dependencies无损分解lossless decomposition原子域atomic domains第一范式(1NF) first normal form(1NF)合法关系legal relations超码super keyR 满足 F R satisfies FF在R上成立 F holds on RBoyce-Codd 范式BCNF Boyce-Codd normal form(BCNF)保持依赖dependency preservation第三范式(3NF) third normal form(3NF)平凡的函数依赖thivial functional dependencies函数依赖集的闭包closure of a set of functional dependenciesArmstrong 公理Armstrong s axioms属性集闭包closure of attribute setsF 在Ri 上的限定restriction of F to Ri正贝 1 覆盖canonical cover无关属T生extraneous attributesBCNF 分解算法BCNF decomposition algorithm3NF 分解算法3NF decomposition algorithm多值依赖multivalued dependencies第四范式(4NF) fourth normal form(4NF)多值依赖的限定restriction of a multivalued independency投影-连接范式(PJNF) project-join normal form(PJNF)域-码范式(DKNF ) domain-key normal form(DKNF)泛关系universal relation唯一角色假设unique-role assumption 去标准化denormalization。
数据库中英文对照外文翻译文献
中英文对照外文翻译Database Management SystemsA database (sometimes spelled data base) is also called an electronic database , referring to any collection of data, or information, that is specially organized for rapid search and retrieval by a computer. Databases are structured to facilitate the storage, retrieval , modification, and deletion of data in conjunction with various data-processing operations .Databases can be stored on magnetic disk or tape, optical disk, or some other secondary storage device.A database consists of a file or a set of files. The information in these files may be broken down into records, each of which consists of one or more fields. Fields are the basic units of data storage , and each field typically contains information pertaining to one aspect or attribute of the entity described by the database . Using keywords and various sorting commands, users can rapidly search , rearrange, group, and select the fields in many records to retrieve or create reports on particular aggregate of data.Complex data relationships and linkages may be found in all but the simplest databases .The system software package that handles the difficult tasks associated with creating ,accessing, and maintaining database records is called a database management system(DBMS).The programs in a DBMS package establish an interface between the database itself and the users of the database.. (These users may be applications programmers, managers and others with information needs, and various OS programs.)A DBMS can organize, process, and present selected data elements form the database. This capability enables decision makers to search, probe, and query database contents in order to extract answers to nonrecurring and unplanned questions that aren’t available in regular reports. These questions might initially be vague and/or poorly defined ,but people can “browse” through the database until they have the needed information. In short, the DBMS will “manage” the stored data items and assemble the needed items from the common database in response to the queries of those who aren’t programmers.A database management system (DBMS) is composed of three major parts:(1)a storage subsystemthat stores and retrieves data in files;(2) a modeling and manipulation subsystem that provides the means with which to organize the data and to add , delete, maintain, and update the data;(3)and an interface between the DBMS and its users. Several major trends are emerging that enhance the value and usefulness of database management systems;Managers: who require more up-to-data information to make effective decisionCustomers: who demand increasingly sophisticated information services and more current information about the status of their orders, invoices, and accounts.Users: who find that they can develop custom applications with database systems in a fraction of the time it takes to use traditional programming languages.Organizations : that discover information has a strategic value; they utilize their database systems to gain an edge over their competitors.The Database ModelA data model describes a way to structure and manipulate the data in a database. The structural part of the model specifies how data should be represented(such as tree, tables, and so on ).The manipulative part of the model specifies the operation with which to add, delete, display, maintain, print, search, select, sort and update the data.Hierarchical ModelThe first database management systems used a hierarchical model-that is-they arranged records into a tree structure. Some records are root records and all others have unique parent records. The structure of the tree is designed to reflect the order in which the data will be used that is ,the record at the root of a tree will be accessed first, then records one level below the root ,and so on.The hierarchical model was developed because hierarchical relationships are commonly found in business applications. As you have known, an organization char often describes a hierarchical relationship: top management is at the highest level, middle management at lower levels, and operational employees at the lowest levels. Note that within a strict hierarchy, each level of management may have many employees or levels of employees beneath it, but each employee has only one manager. Hierarchical data are characterized by this one-to-many relationship among data.In the hierarchical approach, each relationship must be explicitly defined when the database is created. Each record in a hierarchical database can contain only one key field and only one relationship is allowed between any two fields. This can create a problem because data do not always conform to such a strict hierarchy.Relational ModelA major breakthrough in database research occurred in 1970 when E. F. Codd proposed a fundamentally different approach to database management called relational model ,which uses a table asits data structure.The relational database is the most widely used database structure. Data is organized into related tables. Each table is made up of rows called and columns called fields. Each record contains fields of data about some specific item. For example, in a table containing information on employees, a record would contain fields of data such as a person’s last name ,first name ,and street address.Structured query language(SQL)is a query language for manipulating data in a relational database .It is nonprocedural or declarative, in which the user need only specify an English-like description that specifies the operation and the described record or combination of records. A query optimizer translates the description into a procedure to perform the database manipulation.Network ModelThe network model creates relationships among data through a linked-list structure in which subordinate records can be linked to more than one parent record. This approach combines records with links, which are called pointers. The pointers are addresses that indicate the location of a record. With the network approach, a subordinate record can be linked to a key record and at the same time itself be a key record linked to other sets of subordinate records. The network mode historically has had a performance advantage over other database models. Today , such performance characteristics are only important in high-volume ,high-speed transaction processing such as automatic teller machine networks or airline reservation system.Both hierarchical and network databases are application specific. If a new application is developed ,maintaining the consistency of databases in different applications can be very difficult. For example, suppose a new pension application is developed .The data are the same, but a new database must be created.Object ModelThe newest approach to database management uses an object model , in which records are represented by entities called objects that can both store data and provide methods or procedures to perform specific tasks.The query language used for the object model is the same object-oriented programming language used to develop the database application .This can create problems because there is no simple , uniform query language such as SQL . The object model is relatively new, and only a few examples of object-oriented database exist. It has attracted attention because developers who choose an object-oriented programming language want a database based on an object-oriented model. Distributed DatabaseSimilarly , a distributed database is one in which different parts of the database reside on physically separated computers . One goal of distributed databases is the access of informationwithout regard to where the data might be stored. Keeping in mind that once the users and their data are separated , the communication and networking concepts come into play .Distributed databases require software that resides partially in the larger computer. This software bridges the gap between personal and large computers and resolves the problems of incompatible data formats. Ideally, it would make the mainframe databases appear to be large libraries of information, with most of the processing accomplished on the personal computer.A drawback to some distributed systems is that they are often based on what is called a mainframe-entire model , in which the larger host computer is seen as the master and the terminal or personal computer is seen as a slave. There are some advantages to this approach . With databases under centralized control , many of the problems of data integrity that we mentioned earlier are solved . But today’s personal computers, departmental computers, and distributed processing require computers and their applications to communicate with each other on a more equal or peer-to-peer basis. In a database, the client/server model provides the framework for distributing databases.One way to take advantage of many connected computers running database applications is to distribute the application into cooperating parts that are independent of one anther. A client is an end user or computer program that requests resources across a network. A server is a computer running software that fulfills those requests across a network . When the resources are data in a database ,the client/server model provides the framework for distributing database.A file serve is software that provides access to files across a network. A dedicated file server is a single computer dedicated to being a file server. This is useful ,for example ,if the files are large and require fast access .In such cases, a minicomputer or mainframe would be used as a file server. A distributed file server spreads the files around on individual computers instead of placing them on one dedicated computer.Advantages of the latter server include the ability to store and retrieve files on other computers and the elimination of duplicate files on each computer. A major disadvantage , however, is that individual read/write requests are being moved across the network and problems can arise when updating files. Suppose a user requests a record from a file and changes it while another user requests the same record and changes it too. The solution to this problems called record locking, which means that the first request makes others requests wait until the first request is satisfied . Other users may be able to read the record, but they will not be able to change it .A database server is software that services requests to a database across a network. For example, suppose a user types in a query for data on his or her personal computer . If the application is designed with the client/server model in mind ,the query language part on the personal computer simple sends the query across the network to the database server and requests to be notified when the data are found.Examples of distributed database systems can be found in the engineering world. Sun’s Network Filing System(NFS),for example, is used in computer-aided engineering applications to distribute data among the hard disks in a network of Sun workstation.Distributing databases is an evolutionary step because it is logical that data should exist at the location where they are being used . Departmental computers within a large corporation ,for example, should have data reside locally , yet those data should be accessible by authorized corporate management when they want to consolidate departmental data . DBMS software will protect the security and integrity of the database , and the distributed database will appear to its users as no different from the non-distributed database .In this information age, the data server has become the heart of a company. This one piece of software controls the rhythm of most organizations and is used to pump information lifeblood through the arteries of the network. Because of the critical nature of this application, the data server is also the one of the most popular targets for hackers. If a hacker owns this application, he can cause the company's "heart" to suffer a fatal arrest.Ironically, although most users are now aware of hackers, they still do not realize how susceptible their database servers are to hack attacks. Thus, this article presents a description of the primary methods of attacking database servers (also known as SQL servers) and shows you how to protect yourself from these attacks.You should note this information is not new. Many technical white papers go into great detail about how to perform SQL attacks, and numerous vulnerabilities have been posted to security lists that describe exactly how certain database applications can be exploited. This article was written for the curious non-SQL experts who do not care to know the details, and as a review to those who do use SQL regularly.What Is a SQL Server?A database application is a program that provides clients with access to data. There are many variations of this type of application, ranging from the expensive enterprise-level Microsoft SQL Server to the free and open source mySQL. Regardless of the flavor, most database server applications have several things in common.First, database applications use the same general programming language known as SQL, or Structured Query Language. This language, also known as a fourth-level language due to its simplistic syntax, is at the core of how a client communicates its requests to the server. Using SQL in its simplest form, a programmer can select, add, update, and delete information in a database. However, SQL can also be used to create and design entire databases, perform various functions on the returned information, and even execute other programs.To illustrate how SQL can be used, the following is an example of a simple standard SQL query and a more powerful SQL query:Simple: "Select * from dbFurniture.tblChair"This returns all information in the table tblChair from the database dbFurniture.Complex: "EXEC master..xp_cmdshell 'dir c:\'"This short SQL command returns to the client the list of files and folders under the c:\ directory of the SQL server. Note that this example uses an extended stored procedure that is exclusive to MS SQL Server.The second function that database server applications share is that they all require some form of authenticated connection between client and host. Although the SQL language is fairly easy to use, at least in its basic form, any client that wants to perform queries must first provide some form of credentials that will authorize the client; the client also must define the format of the request and response.This connection is defined by several attributes, depending on the relative location of the client and what operating systems are in use. We could spend a whole article discussing various technologies such as DSN connections, DSN-less connections, RDO, ADO, and more, but these subjects are outside the scope of this article. If you want to learn more about them, a little Google'ing will provide you with more than enough information. However, the following is a list of the more common items included in a connection request.Database sourceRequest typeDatabaseUser IDPasswordBefore any connection can be made, the client must define what type of database server it is connecting to. This is handled by a software component that provides the client with the instructions needed to create the request in the correct format. In addition to the type of database, the request type can be used to further define how the client's request will be handled by the server. Next comes the database name and finally the authentication information.All the connection information is important, but by far the weakest link is the authentication information—or lack thereof. In a properly managed server, each database has its own users with specifically designated permissions that control what type of activity they can perform. For example, a user account would be set up as read only for applications that need to only access information. Another account should be used for inserts or updates, and maybe even a third account would be used for deletes.This type of account control ensures that any compromised account is limited in functionality. Unfortunately, many database programs are set up with null or easy passwords, which leads to successful hack attacks.译文数据库管理系统介绍数据库（database,有时拼作data base）又称为电子数据库，是专门组织起来的一组数据或信息，其目的是为了便于计算机快速查询及检索。
数据库原理基本概念英文解释
数据库原理基本概念Basic concepts of database theory一、数据---DataData is everything.Data can exist in a variety of forms -- as digital numbers, text, image, sound, video and etc.二、数据库---DatabaseA database is a repository for a collection of computerized data files.A database is an organized collection of data for one or more purposes, usually in digital form. The data are typically organized to model relevant aspects of reality (for example, the availability of rooms in hotels), in a way that supports processes requiring this information (for example, finding a hotel with vacancies). The term "database" refers both to the way its users view it, and to the logical and physical materialization of its data, content, in files, computer memory, and computer data storage.三、数据库系统---DBS(Database System)A database system is a term that is typically used to encapsulate the constructs of a data model, database Management system (DBMS) and database.四、数据库管理系统---DBMS(Database ManagementSystem)A database management system (DBMS) is a software package with computer programs that control the creation, maintenance, and the use of a database. It allows organizations to conveniently develop databases for various applications by database administrators (DBAs) and other specialists.A collection of programs that enables you to store, modify, and extract information from a database.五、数据库管理员---DBA(Database Administrator)A database administrator is a person responsible for the design, implementation, maintenance and repair of an organization's database.六、模式---SchemaA database schema of a database system is its structure described in a formal language supported by the database management system (DBMS) and refers to the organization of data to create a blueprint of how a database will be constructed.In other words, schema is the structure of the database that defines the objects in the database.七、内模式---Internal SchemaInternal Schema: storage schema– Describes how data is stored and what the physical structureof data is.– Totally dependent on particular implementation.– There is only one internal schema in a DB.八、外模式---External SchemaExternal Schema: user schema or subschema– Interface between users and DBS– Describes the logical structure of some local data oriented tosome applications and users– There may be many external schemata in a DB.九、三级模式---Three Levels of Schema-Physical level: describes how a record (e.g., customer) is stored.-Logical level: describes data stored in database, and therelationships among the data.-View level: application programs hide details of data types. Views can also hide information (such as an e mployee’s salary)for security purposes.十、映像---MappingData mapping is the process of creating data element mappings between two distinct data models. Data mapping is used as a first step for a wide variety of data integration tasks including:●Data transformation or data mediation between a data source anda destination●Identification of data relationships as part of data lineageanalysis●Discovery of hidden sensitive data such as the last four digitssocial security number hidden in another user id as part of a datamasking or de-identification project●Consolidation of multiple databases into a single data base andidentifying redundant columns of data for consolidation orelimination十一、逻辑独立性---Logical Independence When schema changes (e.g., new relation/new attribute added), DBA changes the Ex-schema/schema mapping, so the external schema can stay unchanged, i.e. applications needn’t be changed.十二、物理独立性---Physical Independence When internal schema changes ，DBA changes the schema/internal schema mapping, so the schema can stay unchanged . Thus, the external schema also keeps the same.十三、数据模型---Data ModelA data model in software engineering is an abstract model, that documents and organizes the business data for communication between team members and is used as a plan for developing applications, specifically how data is stored and accessed.A data model can be sometimes referred to as a data structure, especially in the context of programming languages. Data models are often complemented by function models, especially in the context of enterprise models.。
数据库管理系统中英文对照
数据库管理系统的介绍Raghu Ramakrishnan数据库（database,有时拼作data base）又称为电子数据库，是专门组织起来的一组数据或信息，其目的是为了便于计算机快速查询及检索。
数据库的结构是专门设计的，在各种数据处理操作命令的支持下，可以简化数据的存储，检索，修改和删除。
数据库可以存储在磁盘，磁带，光盘或其他辅助存储设备上。
数据库由一个或一套文件组成，其中的信息可以分解为记录，每一记录又包含一个或多个字段（或称为域）。
字段是数据存取的基本单位。
数据库用于描述实体，其中的一个字段通常表示与实体的某一属性相关的信息。
通过关键字以及各种分类（排序）命令，用户可以对多条记录的字段进行查询，重新整理，分组或选择，以实体对某一类数据的检索，也可以生成报表。
所有数据库（最简单的除外）中都有复杂的数据关系及其链接。
处理与创建，访问以及维护数据库记录有关的复杂任务的系统软件包叫做数据库管理系统（DBMS）。
DBMS软件包中的程序在数据库与其用户间建立接口。
（这些用户可以是应用程序员，管理员及其他需要信息的人员和各种操作系统程序）。
DBMS可组织，处理和表示从数据库中选出的数据元。
该功能使决策者能搜索，探查和查询数据库的内容，从而对在正规报告中没有的，不再出现的且无法预料的问题做出回答。
这些问题最初可能是模糊的并且（或者）是定义不恰当的，但是人们可以浏览数据库直到获得所需的信息。
简言之，DBMS将“管理”存储的数据项，并从公共数据库中汇集所需的数据项以回答非程序员的询问。
DBMS由3个主要部分组成：（1）存储子系统，用来存储和检索文件中的数据；（2）建模和操作子系统，提供组织数据以及添加，删除，维护，更新数据的方法；（3）用户和DBMS之间的接口。
在提高数据库管理系统的价值和有效性方面正在展现以下一些重要发展趋势；1.管理人员需要最新的信息以做出有效的决策。
2.客户需要越来越复杂的信息服务以及更多的有关其订单，发票和账号的当前信息。
英文数据库介绍及使用
英数据库： OCLC CSA EI PQDD • 专业性数据库 银盘（Webspirs） INSPEC
综合性数据库-OCLC
• OCLC（Online Computer Library Center），即 图书馆联机计算机中心，是世界上最大的提供 文献信息服务的机构之一。创建于1967年，据 2000 2000年底统计，用户已有82个国家和地区的 82
外文文献检索实习要求：
• 根据需要选用一种数据库进行检索，注 明选用的数据库名称，检索词（须使用 两个或两个以上检索词进行逻辑组配）， 及检索结果。 • 摘抄一条检索结果。
世界三大农业文献数据库：
CABI 国际农业和生物技术文摘：由国际农业和 国际农业和生物技术文摘： 生物科学中心CABI编辑， 收录 编辑， 生物科学中心 编辑 收录120多个国家和 多个国家和 地区用70多种文字发表的农 多种文字发表的农、 地区用 多种文字发表的农、林、生命科学文 以文摘为主。 献。以文摘为主。 AGRICOLA 美国农业文献索引：主要收录美国 美国农业文献索引： 农业图书馆编辑的书目型数据库（题录）， ），主 农业图书馆编辑的书目型数据库（题录），主 要收录美国和北美地区， 要收录美国和北美地区，以及其它国家的各种 类型的文献，以题录为主。 类型的文献，以题录为主 AGRIS 国际农业文献索引：由FAO生产，收录 国际农业文献索引： 生产， 生产 135个国家和地区的 个国家和地区的146个AGRIS中心农业文献 个国家和地区的 个 中心农业文献 发展中国家为主），题录和文摘。 ），题录和文摘 （发展中国家为主），题录和文摘。
db开头的英文词组
db开头的英文词组数据库（Database）是现代计算机系统中的一个重要组成部分，广泛应用于各个领域。
在数据库中，我们经常会遇到以"DB"开头的英文词组。
本文将介绍几个常见的DB开头的英文词组及其应用。
DBMS（Database Management System）DBMS是数据库管理系统的缩写，它是一种软件系统，用于管理数据库中的数据。
DBMS允许用户创建、访问、更新和维护数据库，提供了数据存储、数据操作、数据安全等功能。
常见的DBMS包括MySQL、Oracle、SQL Server等。
DBA（Database Administrator）DBA是数据库管理员的缩写，他们负责数据库的设计、安装、配置和维护工作，确保数据库系统的正常运行。
DBA还负责监控数据库的性能，优化数据库结构，确保数据的安全性和完整性。
DBS（Database System）DBS是数据库系统的缩写，它是由DBMS、数据库和应用程序组成的一个整体。
数据库系统是为了高效地管理和组织大量数据而设计的，它可以提供数据共享、数据一致性、数据安全等功能。
DBDC（Database Distributed Computing）DBDC是数据库分布式计算的缩写，它是一种数据库架构，将数据库分布在多台计算机上，通过网络连接进行数据交换和共享，提高了数据库的性能和可靠性。
DBDC常用于大规模的企业应用系统或互联网应用中。
DBaaS（Database as a Service）DBaaS是数据库即服务的缩写，它是一种云计算服务模式，在云平台上提供数据库服务。
用户无需关心数据库的底层架构和维护工作，只需通过网络访问和使用数据库。
DBaaS提供了简单、快速和灵活的数据库解决方案，降低了数据库的运维成本。
DBR（Database Replication）DBR是数据库复制的缩写，它是一种数据库备份方案，将数据库的数据复制到其他服务器上以提供冗余和灾备能力。
开发英文的名词解释
开发英文的名词解释在今天这个全球化的时代，掌握英语已经成为一项重要的技能。
不仅在个人职业发展中，能够流利地使用英语，尤其是掌握一些专业术语和名词，对于从事软件开发、科技创新以及国际交流等行业的人来说尤为重要。
本文将就开发英文中一些常见的名词进行解释，以帮助读者更好地理解和应用这些术语。
1. Agile Development（敏捷开发）敏捷开发是一种以迭代、自适应、协作为核心的软件开发方法。
其目标是实现快速、灵活且高质量的软件交付。
在敏捷开发中，开发团队通过迭代式的开发周期，将复杂的需求切分为小而可管理的任务，并充分利用用户反馈来不断优化产品。
2. Scrum（Scrum框架）Scrum是一种敏捷开发的项目管理框架，强调团队合作、迭代开发和持续改进。
在Scrum中，团队通常由产品负责人、Scrum Master和开发人员组成。
通过制定计划、日常会议和回顾等各种仪式，Scrum框架使得团队能够高效地协作并交付高质量的产品。
3. User Story（用户故事）用户故事是敏捷开发中的一种需求描述方式，用于记录用户的功能需求。
这种描述方法通常以用户的视角来阐述功能的需求和价值。
用户故事通常由简短的描述、验收条件和对应的优先级组成，以便开发团队更好地理解用户需求并对其进行实现。
4. API（Application Programming Interface，应用程序编程接口）API是一种定义了不同软件组件之间交互的接口。
它提供了一组规范和协议，允许不同的软件系统之间进行数据交换和功能调用。
API的存在可以简化开发人员的工作，提高系统的可复用性和扩展性。
5. Debugging（调试）调试是在软件开发过程中查找和修复程序中错误和问题的过程。
调试包括通过跟踪程序执行、打印变量值和使用调试工具来检测和解决bug。
调试是开发过程中不可或缺的一环，它能够提高软件的稳定性和可靠性。
6. Framework（框架）框架是一种软件开发的架构，提供了一个基础的结构和组件，使开发人员能够更快、更简单地构建应用程序。
英文数据库(pubmed)
（5）Details（详细检索式） ） （详细检索式） 主要用于查看PubMed的检索策略，即 的检索策略， 主要用于查看 的检索策略 词汇自动转换结果。 词汇自动转换结果。 使用Details键还可对检索策略进行修改： 键还可对检索策略进行修改： 使用 键还可对检索策略进行修改 点击Query Translation框中的检索策略， 框中的检索策略， 点击 框中的检索策略 将其修改后点击Search 将其修改后点击
[Text Word]：在TI、AB、MeSH、PS、SH等 字段检索
（2）著者检索 ） 姓在前用全称，名在后用缩写。 姓在前用全称，名在后用缩写。 比如检索李伟（ 比如检索李伟（Li Wei）发表的文献时， ）发表的文献时， 检索式应为Li ， 检索式应为 W，但此时的检索结果同时包 含Li WH，Li WY等，为进行精确检索，应 ， 等 为进行精确检索， 用双引号将检索词括起来， 用双引号将检索词括起来，如"Li W"。如果 。 仅仅采用姓氏检索， 仅仅采用姓氏检索，一定要附加著者字段的 。 标识符[au]，比如：Li[au]。 标识符 ，比如：
（2）Preview/Index（预检索和索引浏览） ） （预检索和索引浏览）
– 在显示文献题录前，显示检索策略和检索 在显示文献题录前， 结果的数量。 结果的数量。 – 可修改检索策略：提供二次检索检索功能。 可修改检索策略：提供二次检索检索功能。 – 从索引词表中浏览并选择词条，完善检索 从索引词表中浏览并选择词条， 策略： 策略：在“Preview/Index ”页面下方的提 页面下方的提 问框内输入检索词，点击 问框内输入检索词，点击Index，系统显示 ， 相应的索引词表， 相应的索引词表，然后可进一步选词进行 二次检索。 二次检索。
【基础】中英文翻译数据库基础精品
【关键字】基础Database FundamentalsIntroduction to DBMSA database management system (DBMS) is an important type of programming system, used today on the biggest and the smallest computers. As for other major forms of system software, such as compilers and operating systems, a well-understood set of principles for database management systems has developed over the years, and these concepts are useful both for understanding how to use these systems effectively and for designing and implementing DBMS's. DBMS is a collection of programs that enables you to store, modify, and extract information from a database. There are many different types of DBMS's, ranging from small systems that run on personal computers to huge systems that run on mainframes.There are two qualities that distinguish database management systems from other sorts of programming systems.1) The ability to manage persistent data, and2) The ability to access large amounts of data efficiently.Point 1) merely states that there is a database which exists permanently; the content of this database is the data that a DBMS accesses and manages. Point 2) distinguishes a DBMS from a file system, which also manages persistent data. A DBMS's capabilities are needed most when the amount of data is very large, because for small amounts of data, simple access techniques, such as linear scans of the data, are usually adequate.While we regard the above two properties of a DBMS as fundamental, there are a number ofother capabilities that are almost universally found in commercial DBMS's. These are:(1) Support for at least one data model, or mathematical abstraction through which the user can view the data.(2) Support for certain high-level languages that allow the user to define the structure of data, access data, and manipulate data.(3) Transaction management, the capability to provide correct, concurrent access to the database by many users at once.(4) Access control, the ability to limit access to data by unauthorized users, and the ability to check the validity of data.(5) Resiliency, the ability to recover from system failures without losing data.Data Models Each DBMS provides at least one abstract model of data that allows the user to see information not as raw bits, but in more understandable terms. In fact, it is usually possible to see data at several levels of abstraction. At a relatively low level, a DBMS commonly allows us to visualize data as composed of files.Efficient File Access The ability to store a file is not remarkable: the file system associated with any operating system does that. The capability of a DBMS is seen when we access the data of a file. For example, suppose we wish to find the manager of employee "Clark ". If the company has thousands of employees, It is very expensive to search the entire file to find the one with NAME="Clark ". A DBMS helps us to set up "index files," or "indices," that allow us to access the record for "Clark " in essentially one stroke no matter how large the file is. Likewise, insertion of new records or deletion of old ones can be accomplished in time that is small and essentially constant, independent of the file length. Another thing a DBMS helps us do is navigate among files, that is, to combine values in two or more files to obtain the information we want.Query Languages To make access to files easier, a DBMS provides a query language, or data manipulation language, to express operations on files. Query languages differ in the level of detail they require of the user, with systems based on the relational data model generally requiring less detail than languages based on other models.Transaction Management Another important capability of a DBMS is the ability to manage simultaneously large numbers of transactions, which are procedures operating on the database. Some databases are so large that they can only be useful if they are operated upon simultaneously by many computers: often these computers are dispersed around the country or the world. The database systems use by banks, accessed almost instantaneously by hundreds or thousands of automated teller machines (ATM), as well as by an equal or greater number of employees in the bank branches, is typical of this sort of database. An airline reservation system is another good example.Sometimes, two accesses do not interfere with each other. For example, any number of transactions can be reading your bank balance at the same time, without any inconsistency. But if you are in the bank depositing your salary check at the exact instant your spouse is extracting money from an automatic teller, the result of the two transactions occurring simultaneously and without coordination is unpredictable. Thus, transactions that modify a data item must “lock out” other transactions trying to read or write that item at the same time. A DBMS must therefore provide some form of concurrency control to prevent uncoordinated access to the same data item by more than one transaction.Even more complex problems occur when the database is distributed over many different computer systems, perhaps with duplication of data to allow both faster local access and to protect against the destruction of data if one computer crashes.Security of Data A DBMS must not only protect against loss of data when crashes occur, as we just mentioned, but it must prevent unauthorized access. For example, only users with a certainclearance should have access to the salary field of an employee file, and the DBMS must be able associate with the various users their privileges to see files, fields within files, or other subsets of the data in the database. Thus a DBMS must maintain a table telling for each user known to it, what access privileges the user has for each object. For example, one user may be allowed to read a file, but not to insert or delete data; another may not be allowed to see the file at all, while a third may be allowed to read or modify the file at will.DBMS TypesDesigners developed three different types of database structures: hierarchical, network, and relational. Hierarchical and network were first developed but relational has become dominant. While the relational design is dominant, the older databases have not been dropped. Companies that installed a hierarchical system such as IMS in the 1970s will be using and maintaining these databases for years to come even though new development is being done on relational systems. These older systems are often referred to as legacy systems.数据库基础DBMS 简介数据库管理系统是编程系统中的重要的一种，现今可以用在最大的以及最小的电脑上。
英文合理的名词解释大全
英文合理的名词解释大全1. API（Application Programming Interface）：应用程序编程接口2. artificial intelligence（人工智能）：人工智能是计算机科学中最重要的领域之一，主要是研究计算机或其他“智能”设备如何自行判断、学习、规划、控制、诊断以及改善自身的逻辑思维方式。
3. Cyber security（网络安全）：网络安全指保护网络设施及网络设备的安全防护，以及帮助网络用户和企业保护受到网络攻击的系统、服务和数据。
它尽力确保网络组件、用户和数据能够免受未经授权访问、恶意改变和破坏等攻击。
4. Database（数据库）：数据库是按照数据结构和数据管理方法，结合专业和职业技能信息在一起的电脑程序。
它可以以标准化的格式储存和管理庞大的数据，并能提供用户与该数据库进行交互的功能。
5. Digital transformation（数字化转型）：数字化转型是指企业将各种数字技术，如云计算、物联网、大数据等，整合到内部业务流程之中，以提高效率、优化客户体验和生态系统管理，实现企业管理及商业模式的变革。
6. Internet of Things（物联网）：物联网是一种将传感器、控制器、数据终端和网络系统集成到网络上的基础技术。
它将相互链接，传感和控制无线网络中的物体，以实现应用和安全的连接，并利用集成的数字技术来实施智能控制和协调，从而实现物体之间的无线通讯。
7. Machine learning（机器学习）：机器学习是一种人工智能技术，它使用算法来进行自动学习，在它收集到更加丰富的数据、识别新趋势或优化功能时，能够对事物建立模型，进行精准预测，并且在发现出现异常时及时发出警报。
8. Natural language processing（自然语言处理）：自然语言处理是一门多领域交叉学科，它的目的是使用计算机以自然语言方式进行写作或编程，使机器能够理解、操作和处理人类语言中的文本。
英文数据库
3.2.5 个性化功能
3.保存检索结果
在题录显示界面，标记要保存的记录，点击图标 【Add to list】,此时选中的记录将暂存在服务器上， 然后点击导航条上的按钮【My Profile】，进入检 索结果保存界面，点击按钮【Save】,将所选的记 录保存在服务器上。
4.文章被引用最新信息通报
3.1.1 概述 涉及核技术、生物工程、交通运输、化学和工艺工 程、照明和光学技术、农业工程和食品技术、计算 机和数据处理、应用物理、电子和通信、控制工程、 土木工程、机械工程、材料工程、石油、宇航、汽 车工程以及这些领域的子学科和其他主要工程领域。 其中，化工和工艺的期刊文献最多，约占15%；计 算机和数据处理占12%；应用物理占11%；电子 和通信占12%；另外还有土木工程和机械工程各占 6%。 大约22%的数据是有主题词和摘要的会议论文， 90%的文献是英文文献。
3.1.1 概述 Ei公司从1992年开始收录中国期刊，并于1998年 在清华大学图书馆建立了Ei中国镜像站，2002年又 开通了Ei China 网站/。 访问网址： 1./ （清华大学图书馆镜像） 2./
3.1.4 个性化功能
1.电子邮件通报服务
当数据更新时，系统将按用户设定的检索需求自动 检索，并将检索到的最新数据（包括文献题名、作 者、文摘等），发送至用户的电子邮箱中。 如保存作者检索，并设定Alert服务，可获得该作者 的文章被Ei Compendex收录的最新信息通报；保 存刊名检索，并设定Alert服务，可获得该刊的最新 期目次页。
输入检索式
选择检索方式
图3-1 Ei Compendex简单检索界面
3.1.2 检索方式
2.快速检索（Quick Search）
信息技术常用术语中英文对照表
信息技术常用术语中英文对照表一、基础概念1. 信息（Information）数据经过处理、分析、解释后形成的知识或见解。
2. 数据（Data）未经过处理或解释的原始事实、数字、文字等。
3. 硬件（Hardware）计算机系统的物理组成部分，如中央处理器、内存、硬盘等。
4. 软件（Software）计算机系统中的程序、数据及相关文档的集合。
5. 系统软件（System Software）管理计算机硬件资源、提供用户与硬件交互界面的软件，如操作系统、驱动程序等。
6. 应用软件（Application Software）为特定任务或目的而设计的软件，如文字处理软件、电子表格软件等。
7. 操作系统（Operating System）管理计算机硬件和软件资源的系统软件，提供用户与计算机硬件交互的界面。
8. 数据库（Database）有组织地存储、管理和检索数据的系统。
9. 编程语言（Programming Language）用于编写计算机程序的语言，如Python、Java、C++等。
10. 算法（Algorithm）解决特定问题的一系列步骤或规则。
二、网络与通信11. 互联网（Internet）全球性的计算机网络，连接了世界各地的计算机。
12. 局域网（Local Area Network，LAN）在较小范围内（如家庭、办公室、学校等）连接计算机的网络。
13. 广域网（Wide Area Network，WAN）覆盖较大地理范围的网络，如互联网。
14. 无线网络（Wireless Network）使用无线电波传输数据的网络，如WiFi。
15. 互联网协议（Internet Protocol，IP）定义了数据在互联网输的规则。
16. 传输控制协议（Transmission Control Protocol，TCP）确保数据在互联网上可靠传输的协议。
17. 用户数据报协议（User Datagram Protocol，UDP）提供无连接的、不可靠的数据传输服务。
数据库中英文术语
数据库中英文术语基础理论英文术语中文释义data 数据database(DB) 数据库database system(dbs) 数据库系统database management system 数据库管理系统database administrator 数据库管理员relational model 关系模型relational database 关系型数据库relation 关系table 表网columnattribute 属性IOW 行tuple 元组record 记录domain 域key 键super key 超键candidate key 候选键primary key 主键foreign key 外键DQL 数据查询语句DDL 数据定义语句DML 数据操作语句DQL英文术语中文释义select 查询（选择）from 来自（表）where 条件范围order by 排序group by 分组having 分组条件union 合集union all 合集(重复数据多次显示)intersect 交集minues 差集and 与或主ornotfunction 单行函数aggregate functions 分组函数(多行函数，聚集函数）Cartesianproduct 笛卡尔积join 连接inner join 内连接(通常意义上的有效连接)outer join 外连接left outer join 左外连接right outer join 右外连接full outer join 全外连接nested subqueries 嵌套子查询DML和事务控制英文术语中文释义insert 新增（插入）into 进入values 值update 修改(更新)set 设置delete 删除commit 提交rollback 回滚DDL英文术语中文释义create 新建table 表default 默认值alter 修改add 添加modify 编辑drop 删除rename 重命名drop 删除truncate 截取constraint 约束not null 非空约束primary key 主键约束uniq。
数据库有关的中英文翻译
数据库概论A database consists of a file or a set of files. The information in these files may be broken down into records, each of which consists of one or more fields. Fields are the basic units of data storage, and each field typically contains information pertaining to one aspect or attribute of the entity described by the database. Using keywords and various sorting commands, users can rapidly search, rearrange, group, and select the fields in many records to retrieve or create reports on particular aggregates of data.一个数据库由一个文件或文件集合组成。
这些文件中的信息可分解成一个个记录，每个记录有一个或多个域。
域是数据存储的基本单位，每个域一般含有由数据库描述的属于实体的一个方面或一个特性的信息。
用户使用键盘和各种排序命令，能够快速查找、重排、分组并在查找的许多记录中选择相应的域，建立特定集上的报表。
Database records and files must be organized to allow retrieval of the information. Early systems were arranged sequentially (i.e., alphabetically, numerically, or chronologically); the development of direct-access storage devices made possible random access to data via indexes. Queries are the main way users retrieve database information. Typically, the user provides a string of characters, and the computer searches the database for a corresponding sequence and provides the source materials in which those characters appear. A user can request, for example, all records in which the content of the field for a pe rson’s last name is the word Smith.数据库记录和文件的组织必须确保能对信息进行检索。
《数据库英文翻译》word版
databaseDatabase is in accordance with the data structure to organize, storage and management of data warehouse, which arises from fifty years ago, with the dating of information technology and the development of the market, especially since the 1990s, data management is no longer merely data storage and management, and transformed into user needs of the various data management way. The database has a variety of types, from the most simple storage have various data form to can be carried out mass data storage of large database systems are obtained in each aspect has extensive application.The birth of data managementDatabase's history can be traced back to fifty years ago, when the data management is very simple. Through a lot of classification, comparison and form rendering machine running millions of punched CARDS for data processing, its operation results on paper printed or punched card made new. While the data management is punched card for all these physical storage and handling. However, 1 9 5 1 year Remington Rand corporation (Remington Rand Inc.) an enzyme called Univac I computer launched a a second can input hundreds of recording tape drives, which has caused data management revolution. 1956 IBM produce the first disk drives -- the RAMAC Model 305. This drives have 50 blanks, each blanks diameter is 2 feet, can store 5 MB of data. The biggest advantage is use disk can be randomly access data, and punched CARDS and tape can order access data.Database system appears in the 1960s the bud. When computer began to widely used in data management, the sharing of data put forward more and more high demand. The traditional file system already cannot satisfy people's needs. Manage and share data can unify the database management system (DBMS) came into being. The data model is the core and foundation of database system, various DBMS software are based on a data model. So usually in accordance with the characteristics of the data model and the traditional database system into mesh database, the hierarchy database and relational database three types.Structured query language (SQL)commercial database systems require a query language that is more user friendly. In this chapter,we study SQL, themost influential commercially marketed query language, SQL. SQL uses a combination ofrelational-algebra and relational-calculus constructs.Although we refer to the SQL language as a “query language,” it can do much more than just query a database. It can define the structure of the data, modify data in the database, and specify security constraints.It is not our intention to provide a complete users’ guide for SQL.Rather,we present SQL’s fundamental constructs and concepts. Individual implementations of SQL may differ in details, or may support only a subset of the full language.2.1 BackgroundIBM developed the original version of SQL at its San Jose Research Laboratory (nowthe Almaden Research Center). IBM implemented the language, originally called Sequel, as part of the System R project in the early 1970s. The Sequel language hasevolved since then, and its name has changed to SQL (Structured Query Language). Many products now support the SQL language. SQL has clearly established itself as the standard relational-database language.In 1986, the American National Standards Institute (ANSI) and the International Organization for Standardization (ISO) published an SQL standard, called SQL-86.IBM published its own corporate SQL standard, the Systems Application Architecture Database Interface (SAA-SQL) in 1987. ANSI published an extended standard forSQL, SQL-89, in 1989. The next version of the standard was SQL-92 standard, and the most recent version is SQL:1999. The bibliographic notes provide references to these standards.Chapter 4 SQLIn this chapter, we present a survey of SQL, based mainly on the widely implemented SQL-92 standard. The SQL:1999 standard is a superset of the SQL-92 standard;we cover some features of SQL:1999 in this chapter, and provide more detailed coverage in Chapter 9. Many database systems support some of the new constructs inSQL:1999, although currently no database system supports all the new constructs. You should also be aware that some database systems do not even support all the features of SQL-92, and that many databases provide nonstandard features that we donot cover here.The SQL language has several parts:•Data-definition language (DDL). The SQL DDL provides commands for defining relation schemas, deleting relations, and modifying relation schemas.•Interactive data-manipulation language (DML). The SQL DML includes a query language based on both the relational algebra and the tuple relational calculus. It includes also commands to insert tuples into, delete tuples from,and modify tuples in the database.•View definition.The SQL DDL includes commands for defining views.•Transaction control. SQL includes commands for specifying the beginning and ending of transactions.•Embedded SQL and dynamic SQL. Embedded and dynamic SQL define how SQL statements can be embedded within general-purpose programming languages, such as C, C++, Java, PL/I, Cobol, Pascal, and Fortran.•Integrity.The SQL DDL includes commands for specifying integrity constraints that the data stored in the database must satisfy. Updates that violate integrity constraints are disallowed.•Authorization.The SQL DDL includes commands for specifying access rights to relations and views.In this chapter, we cover the DML and the basic DDL features of SQL.Wealso briefly outline embedded and dynamic SQL, including the ODBC and JDBC standards for interacting with a database from programs written in the C and Java languages.SQL features supporting integrity and authorization are described in Chapter 6,while Chapter 9 outlines object-oriented extensions to SQL.The enterprise that we use in the examples in this chapter, and later chapters, is abanking enterprise with the following relation schemas:Branch-schema = (branch-name, branch-city, assets)Customer-schema = (customer-name, customer-street, customer-city)Loan-schema = (loan-number, branch-name, amount)Borrower-schema = (customer-name, loan-number)Account-schema = (account-number, branch-name, balance)Depositor-schema = (customer-name, account-number)Note that in this chapter, as elsewhere in the text, we use hyphenated names for schema, relations, and attributes for ease of reading. In actual SQL systems, however,hyphens are not valid parts of a name (they are treated as the minus operator). A simple way of translating the names we use to valid SQL names is to replace all hy phens by the underscore symbol (“ ”). For example, we use branch name in place ofbranch-name.2.2 Basic StructureA relational database consists of a collection of relations, each of which is assigneda unique name. Each relation has a structure similar to that presented in Chapter3.SQL allows the use of null values to indicate that the value either is unknown or does not exist. It allows a user to specify which attributes cannot be assigned null values,as we shall discuss in Section4.11.The basic structure of an SQL expression consists of three clauses: select, from,and where.•The select clause corresponds to the projection operation of the relational algebra. It is used to list the attributes desired in the result of a query.•The from clause corresponds to the Cartesian-product operation of the relational algebra. It lists the relations to be scanned in the evaluation of the expression. •The where clause corresponds to the selection predicate of the relational algebra. It consists of a predicate involving attributes of the relations that appear in the fromclause.That the term select has different meaning in SQL than in the relational algebra is an unfortunate historical fact. We emphasize the different interpretations here to minimize potential confusion.A typical SQL query has the formselect A1,A2,...,Anfrom r1,r2,...,rmwhere PEach Ai represents an attribute, and each ri arelation. P is a predicate. The query isequivalent to the relational-algebra expressionΠA1,A2,...,An(σP (r1 × r2 × ··· × rm))If the where clause is omitted, the predicate P is true. However, unlike the result of a relational-algebra expression, the result of the SQL query may containmultiple copies of some tuples; we shall return to this issue in Section 4.2.8.SQL forms the Cartesian product of the relations named in the from clause,performs a relational-algebra selection using the where clause predicate, and then projects the result onto the attributes of the select clause. In practice, SQL may convert the expression into an equivalent form that can be processed more efficiently.However, we shall defer concerns about efficiency to Chapters 13 and 14.In 1974, IBM's Ray Boyce and Don Chamberlin will Codd relational database 12 rule mathematical definition with simple keyword grammar expression comes out, put forward the landmark Structured Query Language (SQL) Language. SQL language features include inquiry, manipulation, definition and control, is a comprehensive, general relational database language, and at the same time, a highly the process of language, only request users do not need pointed out how do pointed out. SQL integration achieved database of all life cycle operation. SQL database provides and relations interact with the method, it can work with standard programming language. The date of the produce, SQL language became the touchstone of inspection relational database, and SQL standard every variation of guidingthe relational database product development direction. However, until the twentieth century, the mid 1970s to the theory of relation in commercial database Oracle and SQL used in DB2.In 1986, the SQL as ANSI relational database language American standards, that same year announced the standard SQL text. Currently SQL standard has three versions. ANSIX3135 - is defined as the basic SQL Database Language - 89, "Enhancement" SQL. A ANS89] [, generally called SQL - 89. SQL - 89 defines the schema definition, data operation and the transaction. SQL - 89 and subsequent ANSIX3168-1989, "Language - Embedded SQL Database, constituted the first generation of SQL standard. ANSIX3135-1992 [ANS92] describes a enhancements of SQL, now called SQL - 92 standards. SQL - 92 including mode operation, dynamic creation and SQL statements dynamic executive, network environment support enhancement. Upon completion of SQL - 92 ANSI and ISO standard, they started SQL3 standards development cooperation. The main features SQL3 abstract data types support, for the new generation of object relational database provides standard.The nature of database data1. Data integrity: database is a unit or an application field of general data processing system, he storage is to belong to enterprise and business departments, organizations and individuals set of related data. Database data from a global view, he according to certain data model organization, description and storage. Based on the structure of data between natural relation, thus can provide all the necessary access route, and data no longer deal with a certain applications, but for total organization, with a whole structural features.2. Data sharing: database data is for many users sharing their information and the establishment, got rid of the specific procedures restrictions and restraint. Different users can use the database according to their respective usage the data; Multiple users can also Shared database data resource, i.e., different users can also access database in the same data. Data sharing each user not only meets the requirements of information, but also meet the various users of information communication between the requirements.Object-oriented databaseAlong with the development of information technology and the market, people found relational database system, while technology is mature, but its limitations is obvious: it can be a very good treatment of so-called "form of data", but of dominating the more and more complex appear helpless type of data. Since the 1990s, technology has been studying and seek new database system. But in what is the development direction of the new database system, industry once is quite confused. The influence of agitation by technology at the time, for quite some time, people put a lot of energy spent on research "object-oriented database system (object oriented database)" or simply as "OO database system". What is worth mentioning, the United States Stonebraker professor proposed object-oriented RDS theory once favored by industry. And in Stonebraker himself Informix spend big money was then appointed technology director always.However, several years of development, spatio-temporal object-oriented relational database system product market development situation is not good. Theoretically perfect sex didn't bring market warm response. The main reason of success, the main design thought database products with new database system is an attempt to replace the existing database system. This for many has been using database system for years and accumulated the massive job data, especially big customer for customers, is unable to withstand the conversion between old and new data that huge workload and big spending. In addition, object-oriented RDS system makes query language extremely complex, so whether database development businessman or application customers depending on the complicated application technology to be a dangerous road.Basic structureThe basic structure of database, reflects the three levels of observation database of three different Angle.(1) physical data layer.It is the most lining, is database on physical storage equipment actually stored data collection. These data are raw data, the object, the user isprocessed by internal model describing the throne of handled the instructions of string, character and word.(2) conceptual data layer.It is a layer of database, is among the whole logic said. Database Points out the logic of each data definition and the logical connection between data collection of storage and record, is. It is related to the database all objects logical relationship, not their physical condition, is under the database administrator concept of database.(3) logical data layer.It is the user sees and use the database, says one or some specific users use collections of data, namely the logical record set.Database different levels is the connection between conversion by mapping.Main features(1) to implement the data sharing.Data sharing contains all users can also access database data, including the user can use all sorts of ways to use the database through interfaces, and provide data sharing.(2) reduce data redundancy.Compared with the file system, because the database to achieve data sharing so as to avoid the user respective establish application documentation. Reduce a lot of repeating data, reduce the data redundancy, maintain the consistency of the data.(3) data of independence.Data independence including database database of logical structure and application independent, also including data physical structure change does not affect the data of the logical structure.(4) data realize central control.File management mode, data in a decentralized state, different user or same users in different treatment had no relation between the documents.Using the database of data can be concentrated control and management, and through the data model of data organization and said the relation between data.(5) the data consistency and maintainability, to ensure the safety and reliability of the data.Mainly includes: (1) the safety control: to prevent data loss, error updating and excessive use; (2) the integrity control: ensure data accuracy, effectiveness and compatibility; (3) the concurrent control: make in the same time period to allow data realization muli-access, and can prevent users of abnormal interaction between; (4) fault finding and recovery: the database management system provides a set of method, can isolate faults and repair fault, thereby preventing data breaches(6) fault recovery.The database management system provides a set of method, can isolate faults and repair fault, thereby preventing data breaches. Database system can restore database system is running as soon as possible, is probably the fault occurred in the physical or logical error. For instance, in system caused by incorrect operation data error, etc.Database classification1. The MaiJie openPlant real-time databaseReal-time database system is a new field in database theory expansion, in power, chemical, steel, metallurgy, papermaking, traffic control and securities finance and other fields has a very broad application prospect. It can provide enterprises with high speed, timely real-time data services, to the rapidly changing real-time data to carry on the long-term effective history storage, is a factory control layer (fieldbus, DCS, PLC, etc) and production management system of the connection between the bridge, also process simulation, advanced control, online optimization, fault diagnosis system data platform.OpenPlant real-time database system used in today's advanced technology and architecture, can realize safe, stable and field each control system of the interface, and collected data efficient data compression and China's longhistory of storage, meanwhile, we also provide convenient client application and general data interface (API/DDE/ODBC/JDBC/OPC, etc.), make the enterprise management and decision makers can prompt, and comprehensive understanding of the current production situation, also can look back at past production conditions, the timely discovery and the problems existing in the production, improve equipment utilization rate, reduce production cost, the enhancement enterprise's core competitive ability.2. IBM DB2As the pioneer and relational database fields, IBM pilot in 1977 completed System R System prototype, 1980 began to provide integrated database server - System / 38, followed by SQL/DSforVSE and VM, and its initial version is closely related with SystemR research prototype. In 1983 forMVSV1 DB2 launch. This version of the objective is to provide the new plan promised simplicity, data don't correlation and user productivity. 1988 DB2 for MVS provides a powerful online transaction processing (OLTP) support, 1989 and 1993 respectively to remote work unit and distributed work unit realized distributed database support. Recently launched Universal Database 6.1 is DB2 Database model gm, is the first online function with multimedia relational Database management system, support includes a series of platform, Linux.3. OracleOracle predecessor called SDL Ellison and another by a benchwarmer in 1977 founded two programmers, they have developed their own fist product in the market, a large sale, 1979, Oracle company introduces the first commercial SQL relational database management system. Oracle corporation is the earliest development relational database, its product support and producers of the most widely operating system platform. Now Oracle relational database products market share a front-runner.4. InformixInformix founded in 1980, the purpose is for Unix operating system to provide professional such open relational database products. The company's name from Information and Informix is the combination of Unix. Informix first truly support SQL database products is the relationship between Informix SE(StandardEngine). InformixSE is at the time of the microcomputer Unix environment main database products. It is also the first to be transplanted into the commercial database products on Linux.5. SybaseSybase company was founded in 1984, the company name "Sybase" from "the system" and "database" combination of meaning. One of the company's founder Bob Sybase Epstein is Ingres university edition (and System/R the same period the relational database model products) of main design personnel. The company's first a relational database products are launched in 1987 SQLServer1.0 Sybase may. Sybase are first proposed the structure of database system/Server thoughts, and took the lead in SQLServer Sybase realize.6. SQL ServerIn 1987, Microsoft and IBM cooperative development complete OS / 2, IBM in its sales OS / 2 ExtendedEdition system binding Manager, and 2Database OS/production line is still lack of database of Microsoft products. Therefore, Microsoft will Sybase, Sybase foreign-exchange signed cooperation agreements with the technical development, the use of Sybase based on OS / 2 platform relational database. In 1989, Microsoft released SQL Server version 1.0.7. PostgreSQLPostgreSQL is a characteristic very complete free software objects - relational database management system (ORDBMS), and many of its characteristic is many of today's commercial database predecessor. The earliest PostgreSQL Ingres project started in BSD the. The characteristics of PostgreSQL covering the SQL - 2 / SQL - 92 and SQL - 3. First, it includes can say to the world's most abundant data types of support; Second, at present PostgreSQL is the only support affairs, son query, multiple versions parallel control system, data integrity checking the only features such as a free software database management system.8. MySQLMySQL is a small relational database management system, developers for Sweden mySQL AB corporation. In January 2008, was 16 from takeover. Currently MySQL is widely used in the small and medium-sized websites on the Internet. Because of its small size, speed, overall has low cost, especially open-source this one characteristic, many small and medium-sized web site, in order to reduce the overall cost of ownership website and selected MySQL as website database9 in Access databasesAmerican Microsoft company in 1994 launched microcomputer database management system. It has friendly interface, easy easy to use, development is simple, flexible, and other features, is the interface typical of the new generation of desktop database management system. Its main features below:(1) perfect management, various database objects of strong data organization, user management, safety inspection functions.(2) strong data processing functions, in a group level of network environment, use Access development multi-user database management system have traditional XBASE (DBASE, FoxBASE collectively) database system can achieve client/Server (Cient/Server) structure and the corresponding database security mechanism, the Access has many advanced large database management system has the characteristics, such as transaction processing/error rollback ability, etc.(3) can be easily generate various data object, using the data stored build forms and statements, visibility.(4) as Office suite, and part of the integrated, realize seamless connection version.(5) can use Web searching and release data, realization and Internet connection. Access mainly suitable for small and medium application system, or as a client/server system of the client database.10. SQLiteThe ACID is to comply with SQLite relational databases management system, it contained within a relatively small C library. It is ichardHipp D.Restablished public domain project. Not as common client/server architecture examples, with SQLite engine is not a process of communication independent process, but connected to the program become a major part of it. So the main communication protocol is within the programming language direct API calls. This in gross consumption, time delay and overall simplicity have positive role. The entire database (definition, table, indexing and data itself) are both in the host host stored in a single file. It is through the simple design of starting a business in the whole data files and complete lock.11. FoxPro databaseAt first by American Fox 1988, 1992 Fox launched by Microsoft company, have introduced after the takeover FoxPro2.5, 2.6 and VisualFoxPro etc, its function and performance version has greatly improved. FoxPro2.5, 2.6 into DOS and Windows two versions, respectively in DOS and running Windows environment. FoxPro FoxBASE in function and performance than and have improved greatly, mainly introducing the window, button, list box and text box control such as to enhance the system development capabilities.Common databases1. MySQL is the most popular open source SQL database management system, the company develops by MySQL AB, issuing, and support. MySQL AB is founded by several MySQL developer a commercial company. It is a second-generation open-source company, combined with open source value orientation, method and successful business model.Features:MySql core program using fully multi-threaded programming. Threading is lightweight processes, it can be flexibly provides services for users, and the system resources. But manyMySql can run in different operating systems. Say simply, MySql can support Windows95/98 / NT / 2000 and UNIX, Linux and OS from various operating system platform.MySql have a very flexible and safe access and password system. When a customer and MySql server connection between all the password, theytransmit encrypted, and MySql support host authentication.Support ODBC for Windows. MySql support all the ODBC 2.5 function and many other functions, like this may use Access connections MySql server, thus make the MySql applications are greatly extend.MySql support large database. Although written in Php web page for it as long as can deposit hundreds of above record data is enough, but MySql can easily support millions of recorded database.MySql have a very rapid and stable memory allocation system based on the thread, can continue to use face don't have to worry about its stability.The strong search function. MySql support inquires the ramp of the SELECT and statements all operators and function, and can be in the same query from different database table mixes, thus make inquires the become quicker and easier.PHP provides strong support for MySql, provide a whole set of the PHP function to MySql MySql, carry on the omni-directional support.2. Based on the server is SQLServer database can be used for medium and large capacity data applications, on the function management is much more ambitious than Access. In handling mass data efficiency, backstage development aspects of flexibility, scalability is strong. Because now database are using standard SQL language to database management, so if it is standard SQL language, both basically can generic. 92HeZu nets all rent space can be used both double Access database, while supporting the SQL Server. SQL Server and more extended stored procedure, can use the database size without limit restrictions.Graphical user interface, make the system management and database management more intuitive and simple.The real client/server architecture.Rich programming interface tools for users to program designed to provide more choices.SQL Server with Windows NT, using a fully integrated many functions, suchas NT send and receive messages, management login security, etc. SQL Server can be a very good and Microsoft BackOffice product integration.Has the very good flexibility, can span from running Windows 95/98 laptop to run Windows 2000 large multiprocessor and so on many kinds of platform use.Technical support to the Web, users can easily will database data released on to the Web page.SQL Server provides the data warehouse function, this function only in Oracle and other more expensive DBMS is only found in.3. Access is a desktop database, is suitable only for data quantity is little, in dealing with the application of a database of data and single visit is very good, the efficiency is high. But it's also visit the client can't more than four. The access database has certain limit, if the data reach 100M or so, is very easy to create the server iis feign death, or consume server memory to crash the server.The future development trendWith the expansion of information management content, appeared to rich variety of data model (hierarchical model, meshy model, relation model, object-oriented model, half structural model and so on), the new technology also emerge in endlessly (data streams, Web data management, data mining, etc.). Now every few years, international senior database experts assembled, discusses database research status, problems and future needs the new technology focus attention. The past existing several similar reports include: 1989 The Future Directions inDBMS Laguna BeachParticipants true - DatabaseSystems: Achievements in 1990, Opportunities, 1995. Inmon W.H. Database 1991: constructing The publication of The data warehouse"。
常用数据库英文术语
数据库相关专业术语Distributed Database System ,DDBS 分布式数据系统Object-oriented Database System ,OODBS 面向对象数据库Multimedia Database System ,MDBS 多媒体数据库系统Data Warehouse ,DW 数据仓库Decision Support System , Dss 决策支持系统On-Line Analysis Processing , OLAP 联机分析处理技术Data Mining ,DM 数据挖掘；Big Data 大数据Data Definition Language , DLL 数据库定义语言Data Manipulation Language 数据操纵语言大数据Big Data 的4v 特性：Volume 数据规模大Variety 数据种类多Velocit数据处理速度快Value 数据价值密度低。
Data Definition Langguage ,DDL 数据定义语言; 数据定义语言分数据库模式，外模式，内模式Data Manipulation langguage ,DML 数据操纵语言Conceptual Model 概念模型；Relationship 联系Entity Relationship Model 实体联系模型；Entity Set 实体集Logical Model 逻辑模型；Physical Model 物理模型Attribute 属性; Type 类型; Value 值; Entity Type 实体类型Hierarchial Model 层次模型；Network Model 网络模型Relational Model 关系模型；relational Schma 关系模式Homogeneous 同质的；Tuple 元祖；Record 记录Field 字段；Key 码；Candidate Key 关键字Primary Key 主键；Foreign Key 外键关系运算：Union 并；Difference 差；Intersection 交；Selection 选择；Projection 投影；Join 联结；联结中分类：Equijoin 等值联结；Natural join 自然联结Entity Integrity 实体完整性；Referenatial Integrity 参照完整性User-defined Intergrity 用户定义完整性Referencing Relation 参照关系；Referencing Relation 被参照关系Traget Relation 目标关系Normal Form,NF 模式的范式On-Line Transaion Processing ,OLTP 联系实务处理Interent Information Server ,IIS 信息服务Regedit.exe / Regedit32.exe。
- 1、下载文档前请自行甄别文档内容的完整性，平台不提供额外的编辑、内容补充、找答案等附加服务。
- 2、"仅部分预览"的文档,不可在线预览部分如存在完整性等问题,可反馈申请退款(可完整预览的文档不适用该条件!)。
- 3、如文档侵犯您的权益，请联系客服反馈,我们会尽快为您处理(人工客服工作时间：9:00-18:30)。
Database instance: The collection of information stored in the database at a particular moment.
database schema: The overall design of the database.
File systems: A system of classifying into files (usually arranged alphabetically).
Data inconsistency: The various copies of the same data may no longer agree.
application program: A program that gives a computer instructions that provide the user with tools to accomplish a task
data administrators(DBA): Who is responsible for the management and maintenance of the database server
Query language: The portion of a DML(Data Manipulation language) that involves information retrieval.
Data dictionary : Which is considered t be a special type of table ,which can only be accessed and updated by the database system itself(not a regular user).
relational data model: The data model that uses a collection of tables to represent both data and the relationships among those data.
object-oriented data model: The data model that can be seen as extending the E-R model with notions of encapsulation,methods(function),and object identity.
metadata: data about data.
transactions: A written account of what transpired at a meeting.
concurrency: Acting together, as agents or circumstances or events.
object-relational data model: The data model that combines features of object-oriented data model and relational data model.
Database Language: The language which is used to describe the database,such as SQL language.
Consisetncy constraints: Require to be the same type
Data views: the system hides certain details of how the data are stored and maintained.
Data abstraction: The data that is not associated with any specific instance.
physical data indenpendence: The application programs that do not depend on the physical schema.
entity-relationship model: The data model that is based on a perception of a real world that consists of a collection of basic objects,called entities,and of relationships among these objects.
Database-management system: A collection of interrelated data and a set of programs to access those data.
Database-systems applications: The use of database-systems,for example: Banking,Airlines,Universities and so on.
Data Definition Language: A language which is used to specify the database schema by a set of definitions expressed.
Data Manipulation language: A language which enables users to access or manipulate data as organized by the appropriate a: The levels of abstraction to describe the database design at the physical level.
logical schema: The levels of abstraction to describe the database design at the logicl level.
client and server machines: The client means that any computer that is hooked up to a computer network and the server machines means that a computer that provides client stations with access to files and printers as shared resources to a computer network.They always use together.