分布式数据库和应用程序【英文】
IT专业英语单词
IT专业英语单词IT专业英语单词汇总save 保存savepoint 保存点（for database）SAX （Simple API for XML）scalable 可伸缩的、可扩展的schedule 调度scheduler 调度程序schema 模式、纲目结构scroll bar滚动条scope 作用域、生存空间scope operator 生存空间操作符scope resolution operator 生存空间解析操作符screen 屏幕SDK （Software Development Kit）软件开发包sealed class 密封类search 查找semantics 语义semaphore 信号量sequential container序列式容器server 服务器、服务端serial 串行serialization/serialize 序列化server cursor服务端游标、服务器游标（for database）session 会话（for database）setter 设值函数shared lock 共享锁（for database）sibling 同级side effect 副作用signature 签名single-threaded 单线程slider滑块slot 槽smart pointer 智能指针SMTP （Simple Mail Transfer Protocol）简单邮件传输协议snapshot 截屏图snapshot 快照（for database）specialization 特化specification 规范、规格splitter 切分窗口SOAP （simple object access protocol）简单对象访问协议software 软件source code 源码、源代码SQL （Structured Query Language）结构化查询语言（for database）stack 栈、堆栈stack unwinding 叠辗转开解（此词用于exception主题）standard library 标准库standard template library 标准模板库stateless 无状态的statement 语句、声明static cursor 静态游标（for database）static SQL statements 静态SQL语句（for database）stored procedure 存储过程（for database）status bar 状态条stream 流string 字符串stub 存根subobject子对象subquery 子查询（for database）subroutine 子例程subscript operator 下标操作符subset 子集subtype 子类型support 支持suspend 挂起symbol 记号syntax 语法system databases 系统数据库（for database）system tables 系统表（for database）table 表（for database）table lock 表锁（for database）table-level constraint 表级约束（for database）tape backup 磁带备份（for database）target 标的,目标task switch 工作切换TCP （Transport Control Protocol）传输控制协议template 模板template-idtemplate argument deduction 模板参数推导template explicit specialization 模板显式特化template parameter 模板参数template template parametertemporary object 临时对象temporary table 临时表（for database）text 文本text file 文本文件thin client 瘦客户端third-party 第三方thread 线程thread-safe 线程的throw 抛出、引发（常指发出一个exception）token 符号、标记、令牌（看场合）trace 跟踪transaction 事务（for database）transaction log 事务日志（for database）transaction rollback 事务回滚（for database）transactional replication 事务复制（for database）translation unit 翻译单元traverse 遍历trigger 触发器（for database）two-phase commit 两阶段提交（for database）tupletwo-phase lookup 两阶段查找type 类型UDDI（Universary Description, Discovery and Integration）统一描述、查询与集成UML （unified modeling language）统一建模语言unary function 单参函数unary operator 一元操作符unboxing 拆箱、拆箱转换underflow 下限溢位（相对于overflow）Union query 联合查询（for database）UNIQUE constraints UNIQUE约束（for database）unique index 唯一索引（for database）unmanaged code 非受控代码、非托管代码unmarshal 散集unqualified 未经限定的、未经修饰的URI （Uniform Resource identifier）统一资源标识符URL （Uniform Resource Locator）统一资源定位器user 用户user interface 用户界面value types 值类型variable 变量vector 向量（一种容器，有点类似array）viable 可行的video 视频view 视图VEE （Virtual Execution Engine）虚拟执行引擎vendor 厂商view 视图（for database）virtual function 虚函数virtual machine 虚拟机virtual memory 虚拟内存vowel 元音字母Web Services web服务WHERE clause WHERE子句（for database）wildcard characters 通配符字符（for database）wildcard search 通配符搜索（for database）window 窗口window function 窗口函数window procedure 窗口过程Windows authentication Windows身份验证wizard 向导word 单词word processor 字处理器wrapper 包装、包装器write enable 写启用（for database）write-ahead log 预写日志（for database）write-only 只写WSDL （Web Service Description Language）Web Service描述语言XML Message Interface （XMI） XML消息接口XML （eXtensible Markup Language）可扩展标记语言XSD （XML Schema Definition） XML模式定义语言XSL （eXtensible Stylesheet Language）可扩展样式表语言XSLT （eXtensible Stylesheet Language Transformation）可扩展样式表语言转换xxx based 基于xxx的xxx oriented 面向xxxIT词典-65A2A integration A2A整合abstract 抽象的abstract base class （ABC）抽象基类abstract class 抽象类abstraction 抽象、抽象物、抽象性access 存取、访问access level访问级别access function 访问函数account 账户action 动作activate 激活active 活动的actual parameter 实参adapter 适配器add-in 插件address 地址address space 地址空间address-of operator 取地址操作符ADL （argument-dependent lookup）ADO（ActiveX Data Object）ActiveX数据对象advanced 高级的aggregation 聚合、聚集algorithm 算法alias 别名align 排列、对齐allocate 分配、配置allocator分配器、配置器angle bracket 尖括号annotation 注解、评注API （Application Programming Interface）应用（程序）编程接口app domain （application domain）应用域application 应用、应用程序application framework 应用程序框架appearance 外观append 附加architecture 架构、体系结构archive file 归档文件、存档文件argument引数（传给函式的值）。
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。
DD 分布式数据库
DD -- 分布式数据库科技名词定义中文名称：分布式数据库英文名称：distributed database;DDB定义：数据分存在计算机网络中的各台计算机上的数据库。
应用学科：分布式数据库系统通常使用较小的计算机系统，每台计算机可单独放在一个地方，每台计算机中都有DBMS的一份完整拷贝副本，并具有自己局部的数据库，位于不同地点的许多计算机通过网络互相连接，共同组成一个完整的、全局的大型数据库。
简介这种组织数据库的方法克服了物理中心数据库组织的弱点。
首先，降低了数据传送代价，因为大多数的对数据库的访问操作都是针对局部数据库的，而不是对其他位置的数据库访问；其次，系统的可靠性提高了很多，因为当网络出现故障时，仍然允许对局部数据库的操作，而且一个位置的故障不影响其他位置的处理工作，只有当访问出现故障位置的数据时，在某种程度上才受影响；第三，便于系统的扩充，增加一个新的局部数据库，或在某个位置扩充一台适当的小型计算机，都很容易实现。
然而有些功能要付出更高的代价。
例如，为了调配在几个位置上的活动，事务管理的性能比在中心数据库时花费更高，而且甚至抵消许多其他的优点。
分布式软件系统(Distributed Software Systems)是支持分布式处理的软件系统,是在由通信网络互联的多处理机体系结构上执行任务的系统。
它包括分布式操作系统、分布式程序设计语言及其编译(解释)系统、分布式文件系统和分布式数据库系统等。
分布式操作系统负责管理分布式处理系统资源和控制分布式程序运行。
它和集中式操作系统的区别在于资源管理、进程通信和系统结构等方面。
分布式程序设计语言用于编写运行于分布式计算机系统上的分布式程序。
一个分布式程序由若干个可以独立执行的程序模块组成,它们分布于一个分布式处理系统的多台计算机上被同时执行。
它与集中式的程序设计语言相比有三个特点：分布性、通信性和稳健性。
分布式文件系统具有执行远程文件存取的能力,并以透明方式对分布在网络上的文件进行管理和存取。
有关计算机的英文名词解释
有关计算机的英文名词解释计算机术语解释计算机科技发展迅速，涌现出许多新的英文计算机名词。
本文章将为读者解释一些常见但可能陌生的计算机名词，帮助读者更好地理解计算机科技领域的发展。
1. 人工智能 (Artificial Intelligence, AI)：人工智能是计算机科学的一个分支，旨在使计算机系统具备类似人类智能的能力。
人工智能技术包括机器学习、深度学习和自然语言处理等。
2. 云计算 (Cloud Computing)：云计算是通过网络以可伸缩的方式提供计算资源和服务。
云计算提供了灵活的存储和处理能力，用户可以随时根据自己的需求扩展或缩小计算资源。
3. 大数据 (Big Data)：大数据是指数据量庞大且复杂的数据集合。
大数据通常具有高度的变化性、多样性和高速性，需要使用特殊的技术和工具来处理和分析。
4. 物联网 (Internet of Things, IoT)：物联网是指通过互联网连接和交流的物理设备网络。
物联网使得物理设备能够收集和交换数据，实现智能化的操作和自动化的决策。
5. 区块链 (Blockchain)：区块链是一种去中心化的分布式数据库技术，用于记录交易和数据。
区块链通过将数据分割成多个“区块”并链接在一起，确保数据的可靠性和不可篡改性。
6. 虚拟现实 (Virtual Reality, VR)：虚拟现实是一种通过计算机生成的仿真环境，模拟真实的感觉和体验。
使用虚拟现实技术，用户可以身临其境地体验虚构的场景或参与虚拟的交互活动。
7. 增强现实 (Augmented Reality, AR)：增强现实是一种将虚拟信息与真实世界场景相结合的技术。
通过AR技术，用户可以通过手机、眼镜或其他设备观看现实世界，同时在视野中显示虚拟的图像或信息。
8. 数据挖掘 (Data Mining)：数据挖掘是从大量数据中提取有用信息和模式的过程。
数据挖掘使用统计学、机器学习和数据库技术，帮助分析师发现隐藏在数据背后的趋势和关联。
数据库中英文对照表
DBA词典：数据库设计常用词汇中英文对照表1. Access method（访问方法）：此步骤包括从文件中存储和检索记录。
2. Alias（别名）：某属性的另一个名字。
在SQL中，可以用别名替换表名。
3. Alternate keys（备用键，ER/关系模型）：在实体/表中没有被选为主健的候选键。
4. Anomalies（异常）参见更新异常（update anomalies）5. Application design（应用程序设计）：数据库应用程序生命周期的一个阶段，包括设计用户界面以及使用和处理数据库的应用程序。
6. Attribute（属性）（关系模型）：属性是关系中命名的列。
7. Attribute（属性）（ER模型）：实体或关系中的一个性质。
8. Attribute inheritance（属性继承）：子类成员可以拥有其特有的属性，并且继承那些与超类有关的属性的过程。
9. Base table（基本表）：一个命名的表，其记录物理的存储在数据库中。
10. Binary relationship（二元关系）：一个ER术语，用于描述两个实体间的关系。
例如，panch Has Staff。
11. Bottom-up approach（自底向上方法）：用于数据库设计，一种设计方法学，他从标识每个设计组建开始，然后将这些组件聚合成一个大的单元。
在数据库设计中，可以从表示属性开始底层设计，然后将这些属性组合在一起构成代表实体和关系的表。
12. Business rules（业务规则）：由用户或数据库的管理者指定的附加规则。
13. Candidate key（候选键，ER关系模型）：仅包含唯一标识实体所必须得最小数量的属性/列的超键。
14. Cardinality（基数）：描述每个参与实体的可能的关系数目。
15. Centralized approach（集中化方法,用于数据库设计）：将每个用户试图的需求合并成新数据库应用程序的一个需求集合16. Chasm trap（深坑陷阱）：假设实体间存在一根，但某些实体间不存在通路。
云计算英文术语
云计算术语（中英文对照）1。
自由计算free computing2. 弹性可伸缩elastic and scalable3。
主机host / instance4. 硬盘hard disk/ volume5。
密钥key6。
公开密钥public key7. 映像image / mapping8。
负载均衡load balancing9. 对象存储object storage10。
弹性计算elastic computing11。
按秒计费charged by seconds12。
多重实时副本multiple real-time copy13. 安全隔离security isolation14。
异地副本long-distance copy15. 后端系统back—end system16. 前端系统front-end system17. 写时拷贝技术copy-on-write technique18. 控制台console19。
监控台dashboard20。
远程终端remote terminal21. 服务端口service port22. 模拟主机simulation host display 显示器23. 路由器router24。
多路万兆光纤multiple 10000MB optical fiber25。
密码验证登录password authentication login26. 静态IP static IP27。
动态IP dynamic IP28. 混合云hybrid cloud29. SLA Service Level Agreement服务级别协议30。
分布式存储distributed storage31。
存储柜locker32。
云计算加速器cloud computing accelerator33. NIST National Institute of Standards and Technology 美国国家标准技术研究所34。
Google全球级分布式数据库Spanner
Colossus系统架构
Colossus（GFS II）
GFS将整个系统的节点分为三种角色：GFS Master （总控服务器），GFS Chunkserver（数据块服务器， 简称CS）以及GFS Client（客户端）。 GFS文件被划分为固定大小的数据块（Chunk），由 Master在创建时分配一个64位全局唯一的Chunk句柄。 CS以普通的Linux文件的形式将Chunk存储在磁盘中。 为了保证可靠性，Chunk在不同的机器中复制多份，默 认为三份。 Master中维护了系统的元数据，包括文件及Chunk名字 空间，GFS文件到Chunk之间的映射，Chunk位置信息。 它也负责整个系统的全局控制，如Chunk租约管理，垃 圾回收无用Chunk，Chunk复制等等。Master会定期与 CS通过心跳的方式交换信息。
Colossus（GFS II） [kəˈl ɒsəs]
Colossus是第二代GFS，对应开源世界的新 HDFS。Google文件系统GFS是构建在廉价的 服务器之上的大型分布式系统。它将服务器故 障视为正常现象，通过软件的方式自动容错， 在保证系统可靠性和可用性的同时，大大减少 了系统的成本。 GFS是Google云存储的基石，其它存储系统， 如Google Bigtable，Google Megastore， Google Percolator [p:klet(r)]均直接或者间接 地构建在GFS之上。另外，Google大规模批处 理系统MapReduce也需要利用GFS作为海量数 据的输入输出。
Spanner背景
Spanner 是Google的全球级的分布式数 据库 (Globally-Distributed Database) 。 Spanner的扩展性达到了令人咋舌的全球 级，可以扩展到数百万的机器，数已百计 的数据中心，上万亿的行。更给力的是， 除了夸张的扩展性之外，它还能同时通过 同步复制和多版本来满足外部一致性，可 用性也是很好的。冲破CAP的枷锁，在三 者之间完美平衡。
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John Wieczorek Museum of Vertebrate Zoology, UC Berkeley
DiGIR
1
Distributed Databases
Multiple sources of data …under local control, …with concepts in common …and a desire to deliver data as part of a community.
DiGIR
11
Project Goals
To define a protocol for retrieving structured data from multiple, heterogeneous databases across the Internet To build a reference implementation of both provider and portal software using said protocol
LifeMapper Global Biodiversity Information Facility (GBIF)
DiGIR
7
Distributed vs. centralized
Multiple sources of data …under local control, …with concepts in common …and a desire to deliver data as part of a community
DiGIR
4
Distributed Databases
Mountain and Plains Spatio-Temporal DatabaseInformatics (MaPSTeDI) Ocean Biogeographic Information System (OBIS) Pacific Basin Information Node, National Biological Information Infrastructure (PBIN, NBII) Species Link, Centro de Referê ncia em Informaç ã o Ambiental (Species Link, CRIA) A Virtual Herbarium of the Chicago Region (vPlants) Spatial Analysis of Local Vegetation Inventories Across Scales (SALVIAS) …
DiGIR
8
Distributed vs. centralized
In other words, distribute the headache rather than have one central migraine.
DiGIR
9
DiGIR
Distributed Generic Information Retrieval
DiGIR
2
Distributed Databases
The Species Analyst (TSA) The Integrated Taxonomic Information System (ITIS) FishNet The Mammal Networked Information System (MaNIS) HerpNET The Ornithological Information System (ORNIS) …
John Wieczorek, Stan Blum, Dave Vieglais, P.J. Schwartz
DiGIR
10
Project Rationale
To avoid multiple incongruous development efforts To pool resources and create a community of experts To solve the problem of scalability
5
DiGIR
Distributed Databases
Berkeley Natural History Museums (BNHM) Association of Biological Collections, UC Davis …
DiGIR
6
Distributed Databases
DiGIR
3
Distributed Databases
European Natural History Science Information Network (ENHSIN) Biological Collection Access for Europe (BioCASE) Australia Virtual Herbarium (AVH) Red Mundial de Informació n Sobre Biodiversidad, Comisió n Nacional para el Conocimiento y Uso de la Biodiversidad (REMIB, CONABIO) …
DiGIR
12
Design Goals
To use open protocols and standards, such as HTTP and XML To decouple the protocol, software and semantics To make new data provider installations as easy as possible To have open source development and GNU General Public Licensing
DiGIR
13
DiGIR Architecture