19 Content Management

001 This chapter provides an overview of Oracle's content management features.
本章将概述 Oracle 的内容管理(content management)特性。
002 This chapter contains the following topics: 本章包含以下主题:

Introduction to Content Management

19.1 内容管理简介

004 Oracle Database includes datatypes to handle all the types of rich Internet content such as relational data, object-relational data, XML, text, audio, video, image, and spatial. These datatypes appear as native types in the database. They can all be queried using SQL. A single SQL statement can include data belonging to any or all of these datatypes.
Oracle 数据库中提供了多种数据类型(datatype)供用户存储 Internet 时代的各种信息,例如关系型数据(relational data),对象-关系型数据(object-relational data),XML,文本(text),音频(audio),视频(video),图像(image),及地理空间信息(spatial)等。这些数据类型在 Oracle 中均为原生数据类型(native type),且均可通过 SQL 进行查询。在一个 SQL 语句中可以同时包含上述的所有数据类型。
005 As applications evolve to encompass increasingly richer semantics, they encounter the need to deal with the following kinds of data:
  • Simple structured data
  • Complex structured data
  • Semi-structured data
  • Unstructured data
  • 简单结构化数据(simple structured data)
  • 复杂结构化数据(complex structured data)
  • 半结构化数据(semi-structured data)
  • 非结构化数据(unstructured data)
006 Traditionally, the relational model has been very successful at dealing with simple structured data -- the kind which can fit into simple tables. Oracle added object-relational features so that applications can deal with complex structured data -- collections, references, user-defined types and so on. Queuing technologies, such as Oracle Streams Advanced Queuing, deal with messages and other semi-structured data. This chapter discusses Oracle's technologies to support unstructured data.
在传统的应用程序中,关系型模型就可以很好地处理简单结构化数据,即适宜采用表进行存储的数据。Oracle 还增加了对象-关系特性供应用程序处理复杂结构化数据,如集合(collections),引用(reference),及用户定义类型(user-defined type)等。Oracle Streams Advanced Queuing(数据流高级队列)等队列技术用于处理消息(message)及其他半结构化数据。而本章主要讲述 Oracle 中用于支持非结构化数据的技术。
007 Unstructured data cannot be decomposed into standard components. Data about an employee can be 'structured' into a name (probably a character string), an identification (likely a number), a salary, and so on. But if you are given a photo, you find that the data really consists of a long stream of 0s and 1s. These 0s and 1s are used to switch pixels on or off, so that you see the photo on a display, but it cannot be broken down into any finer structure in terms of database storage.
非结构化数据无法像结构化数据那样被分解为标准的子结构(standard component)。以描述雇员的数据为例,她可以被结构化为名字(可以用字符串存储),身份证明(可用用数字存储),及薪水等子结构。而处理照片等非结构化数据时,数据本身只是由 0 和 1 所构成的长数据流。这些 0 和 1 表示像素的属性,用于显示图像,无法被继续分解为更底层的数据库存储结构。
008 Unstructured data such as text, graphic images, still video clips, full motion video, and sound waveforms tend to be large -- a typical employee record may be a few hundred bytes, but even small amounts of multimedia data can be thousands of times larger. Some multimedia data may reside on operating system files, and it is desirable to access them from the database.
从数据量上看,文本,图像,视频剪辑,电影,音频波形等非结构化数据所需的存储空间十分庞大。一条典型的雇员记录可能只需数百字节(byte),而一条普通的多媒体数据就可能数千倍于前者。从存储位置上看,有时多媒体数据会存储在操作系统的文件系统中,但应用系统需要通过数据库对这些 数据进行统一管理。

Overview of XML in Oracle

19.2 Oracle 的 XML 特性概述

010 Extensible Markup Language (XML) is a tag-based markup language that lets developers create their own tags to describe data that's exchanged between applications and systems. XML is widely adopted as the common language of information exchange between companies. It is human-readable; that is, it is plain text. Because it is plain text, XML documents and XML-based messages can be sent easily using common protocols, such as HTTP or FTP.
XML(Extensible Markup Language,可扩展标记语言)是一种基于标签(tag-based)的标记语言,开发者可以根据需要创建标签,以便在不同应用程序和系统之间交换数据。XML 目前已经被业界作为一种通用的信息交换语言。XML 脚本采用纯文本格式,且为可以阅读的(human-readable)。由于 XML 采用纯文本格式保存,因此 XML 文档及基于 XML 的消息(XML-based message)可以通过 HTTP 或 FTP 等常见通讯协议传输。
011 Oracle XML DB treats XML as a native datatype in the database. Oracle XML DB is not a separate server. The XML data model encompasses both unstructured content and structured data. Applications can use standard SQL and XML operators to generate complex XML documents from SQL queries and to store XML documents.
Oracle XML DB 将 XML 作为数据库的原生数据类型(native datatype)。Oracle XML DB 并非一个单独的服务器。XML 数据模型既可以存储非结构化内容,也可以存储结构化数据。应用程序可以使用标准 SQL 及 XML 操作符(operator)从 SQL 查询中生成复杂的 XML 文档并进行存储。
012 Oracle XML DB provides capabilities for both content-oriented and data-oriented access. For developers who see XML as documents (news stories, articles, and so on), Oracle XML DB provides an XML repository accessible from standard protocols and SQL.
Oracle XML DB 既支持免面向内容(content-oriented)的数据访问,也支持面向数据(data-oriented)的数据访问。开发者可以将 XML 数据作为内容处理(例如,新闻,文章等),Oracle XML DB 具有 XML 资料库(用于存储内容的描述信息),此资料库可以通过标准协议及 SQL 访问。
013 For others, the structured-data aspect of XML (invoices, addresses, and so on) is more important. For these users, Oracle XML DB provides a native XMLType, support for XML Schema, XPath, XSLT, DOM, and so on. The data-oriented access is typically more query-intensive.
开发者还可以使用 XML 处理结构化数据(例如,发票,地址等)。Oracle XML DB 具有原生的 XML 类型(native XMLType),并支持 XML Schema(XML 模式),XPath,XSLT,DOM 等技术。查询量大的系统适合采用面向数据的数据访问。
014 The Oracle XML developer's kits (XDK) contain the basic building blocks for reading, manipulating, transforming, and viewing XML documents, whether on a file system or stored in a database. They are available for Java, C, and C++. Unlike many shareware and trial XML components, the production Oracle XDKs are fully supported and come with a commercial redistribution license. Oracle XDKs consist of the following components:
  • XML Parsers: supporting Java, C, and C++, the components create and parse XML using industry standard DOM and SAX interfaces.
  • XSLT Processor: transforms or renders XML into other text-based formats, such as HTML.
  • XML Schema Processor: supporting Java, C, and C++, allows use of XML simple and complex datatypes.
  • XML Class Generator: automatically generates Java and C++ classes from XSL schemas to send XML data from Web forms or applications.
  • XML Java Beans: visually view and transform XML documents and data with Java components.
  • XML SQL Utility: supporting Java, generates XML documents, DTDs, and schemas from SQL queries.
  • XSQL Servlet: combines XML, SQL, and XSLT in the server to deliver dynamic Web content.
Oracle XML developer's kits(XDK,Oracle XML 开发包)中含有用于读取(reading),操作(manipulating),转换(transforming),及展示(viewing)文件系统或数据库中的 XML 文档的基础开发组件。XDK 以 Java,C,及 C++ 实现。与其他共享版或试用版的 XML 组件不同,Oracle XDKs 能够提供全面的技术支持,且具有商业发布许可(commercial redistribution license)。Oracle XDKs 包括以下组件:
  • XML Parser(XML解析器):此组件使用业界标准的 DOM 及 SAX 接口创建并解析 XML 数据,支持 Java,C,及 C++。
  • XSLT Processor(XSLT 处理器):读取 XML 数据并转换为其他文本格式的数据,例如 HTML。
  • XML Schema Processor(XML 模式处理器):处理 XML 简单及复杂数据类型,支持 Java,C,及 C++。
  • XML Class Generator(XML 类生成器):从 XSL 模板中自动地生成 Java 及 C++ 类,为 Web 表单(form)及应用程序传输 XML 数据。
  • XML Java Beans: 可视化地查看及转换 XML 文档及数据的 Java 组件。
  • XML SQL Utility(XML SQL 工具):从 SQL 查询结果中生成 XML 文档及 DTD,支持 Java。
  • XSQL Servlet:在服务端整合 XML,SQL,及 XSLT,制作动态的 Web 内容。

See Also:



Overview of LOBs

19.3 LOB 数据类型概述

017 The large object (LOB) datatypes BLOB, CLOB, NCLOB, and BFILE enable you to store and manipulate large blocks of unstructured data (such as text, graphic images, video clips, and sound waveforms) in binary or character format. They provide efficient, random, piece-wise access to the data.
大对象(LOB,large object)数据类型包括 BLOBCLOBNCLOB,及 BFILE 类型,供用户存储及操作二进制或字符格式的大型非结构化数据(unstructured data)(例如文本,图形,视频及音频波形)。大对象类型存取效率较高,且支持随机(random)及按块(piece-wise)地访问数据。
018 With the growth of the internet and content-rich applications, it has become imperative that databases support a datatype that fulfills the following:
  • Can store unstructured data
  • Is optimized for large amounts of such data
  • Provides a uniform way of accessing large unstructured data within the database or outside
随着 internet 的飞速发展,以及应用程序所面对的数据类型日趋丰富,对于数据库所支持的数据类型提出了以下要求:
  • 能够存储非结构化数据
  • 对大型数据的存储进行优化
  • 为访问存储于数据库或文件系统的大型非结构化数据提供统一的接口

See Also:

"Overview of LOB Datatypes"


LOB 数据类型概述

Overview of Oracle Text

19.4 Oracle Text 概述

021 Oracle Text indexes any document or textual content to add fast, accurate retrieval of information to internet content management applications, e-Business catalogs, news services, job postings, and so on. It can index content stored in file systems, databases, or on the Web.
Oracle Text 组件能够对文档及文本信息进行索引,实现快速准确的信息获取。此组件可用于 internet 内容管理应用系统(content management application),电子商务编目系统(e-Business catalog),新闻服务,及招聘系统等。Oracle Text 组件能够将索引数据存储在文件系统,数据库,或 Web 上。
022 Oracle Text allows text searches to be combined with regular database searches in a single SQL statement. It can find documents based on their textual content, metadata, or attributes. The Oracle Text SQL API makes it simple and intuitive to create and maintain Text indexes and run Text searches.
Oracle Text 组件能够将文本搜索与常规数据库查询合并到同一 SQL 语句中。Oracle Text 组件可以依据文档的内容,元数据,或各种属性进行搜索。用户可以使用 Oracle Text SQL API 创建并维护文本索引(Text index),或进行文本搜索(text search)。
023 Oracle Text is completely integrated with the Oracle database, making it inherently fast and scalable. The Text index is in the database, and Text queries are run in the Oracle process. The Oracle optimizer can choose the best execution plan for any query, giving the best performance for ad hoc queries involving Text and structured criteria. Additional advantages include the following:
  • Oracle Text supports multilingual querying and indexing.
  • You can index and define sections for searching in XML documents. Section searching lets you narrow down queries to blocks of text within documents. Oracle Text can automatically create XML sections for you.
  • A Text index can span many Text columns, giving the best performance for Text queries across more than one column.
  • Oracle Text has enhanced performance for operations that are common in Text searching, like count hits.
  • Oracle Text leverages scalability features, such as replication.
  • Oracle Text supports local partitioned index.
Oracle Text 组件与 Oracle 数据库是集成在一起的,因此同样具备高性能及高可伸缩性。文本索引存储在数据库中,而文本查询(Text query)运行于 Oracle 进程(process)中。Oracle 优化器(optimizer)能够为各类查询选择最优的执行计划(execution plan),从而确保混合了文本条件及结构化条件的即席查询(ad hoc)的性能。Oracle Text 组件还具备以下特点:
  • Oracle Text 组件支持多语言查询及索引。
  • 用户可以针对 XML 文档中的特定段(section)进行索引或搜索。段搜索(section searching)将查询范围限制到文档中的特定文本段中。Oracle Text 组件能够自动地创建 XML 段。
  • 文本索引可以包含多个文本列(Text column),因此跨多列的文本查询也能获得良好的性能。
  • Oracle Text 组件针对常见的文本搜索操作进行了性能优化,例如出现频次(count hits)统计等。
  • Oracle Text 组件支持可伸缩性特性,例如复制(replication)。
  • Oracle Text 组件支持本地分区索引(local partitioned index)。

Oracle Text Index Types

19.4.1 Oracle Text 索引类型

025 There are three Text index types to cover all text search needs.
  • Standard index type for traditional full-text retrieval over documents and Web pages. The context index type provides a rich set of text search capabilities for finding the content you need, without returning pages of spurious results.
  • Catalog index type, designed specifically for e-Business catalogs. This catalog index provides flexible searching and sorting at Web-speed.
  • Classification index type for building classification or routing applications. This index is created on a table of queries, where the queries define the classification or routing criteria.
为满足各种文本搜索(text search)的需要,Oracle Text 组件提供了三种文本索引类型(Text index type):
  • 标准索引类型(standard index type)用于对文档及 Web 页面进行传统的全文搜索。此种索引支持丰富的文本搜索功能,能够确保用户找到所需的信息,而不会返回用户不需要的结果。
  • 编目索引类型(catalog index type)特为电子商务编目(e-Business catalog)而设计。此种索引用于实现适合于 Web 环境的搜索与排序。
  • 分类索引类型(classification index type)用于开发分类(classification)或路由(routing)性的应用系统。此类索引基于一系列查询创建,其中每个查询定义了一个分类或路由的条件。
026 Oracle Text also provides substring and prefix indexes. Substring indexing improves performance for left-truncated or double-truncated wildcard queries. Prefix indexing improves performance for right truncated wildcard queries.
Oracle Text 组件还支持子字符串索引(substring index)及前缀索引(prefix index)。子字符串索引能够提高左通配符(left-truncated wildcard)或两侧通配符(ouble-truncated wildcard)查询的性能;而前缀索引能够提高左通配符(right-truncated wildcard)查询的性能。

Oracle Text Document Services

19.4.2 Oracle Text 文档服务

028 Oracle Text provides a number of utilities to view text, no matter how that text is stored.
  • Oracle Text supports over 150 document formats through its Inso filtering technology, including all common document formats like XML, PDF, and MS Office. You can also create your own custom filter.
  • You can view the HTML version of any text, including formatted documents such as PDF, MS Office, and so on.
  • You can view the HTML version of any text, with search terms highlighted and with navigation to next/previous term in the text.
  • Oracle Text provides markup information; for example, the offset and length of each search term in the text, to be used for example by a third party viewer.
Oracle Text 组件提供了多种浏览文档的工具,广泛支持各种文档存储格式。
  • Oracle Text 组件通过 Inso 公司的过滤技术(filtering technology)支持超过 150 种文档格式,其中包括 XML,PDF,及微软 Office 等常见的文档格式。用户也可以创建自定义的过滤器(filter)。
  • 用户可以以 HTML 形式浏览各种文档,包括 PDF,微软 Office 等文档格式。
  • 用户可以以 HTML 形式浏览各种文档,并将搜索词(search term)突出显示,还可以在文档中添加指向前后搜索词的导航链接。
  • Oracle Text 组件能够生成额外的标记信息(markup information)。例如,记录出搜索词的长度及在文档中的位置,供第三方文档浏览器使用。

Oracle Text Query Package

19.4.3 Oracle Text 查询包

030 The CTX_QUERY PL/SQL package can be used to generate query feedback, count hits, and create stored query expressions.
CTX_QUERY PL/SQL 包用于生成查询反馈结果(query feedback),出现频次(count hits),还可以将查询表达式(query expression)存储到数据库中。

See Also:

Oracle Text Reference for information about this package


Oracle Text Reference 了解关于此包的详细信息。

Oracle Text Advanced Features

19.4.4 Oracle Text 高级特性

033 With Oracle Text, you can find, classify, and cluster documents based on their text, metadata, or attributes.
通过 Oracle Text 组件,用户可以根据文档的文本,元数据,或其他属性对文档进行查询,分类(classify),及聚类(cluster)操作。
034 Document classification performs an action based on document content. Actions can be assigned category IDs to a document for future lookup or for sending a document to a user. The result is a set, or stream, of categorized documents. For example, assume that there is an incoming stream of news articles. You can define a rule to represent the category of Finance. The rule is essentially one or more queries that select documents about the subject of finance. The rule might have the form 'stocks or bonds or earnings.' When a document arrives that satisfies the rules for this category, the application takes an action, such as tagging the document as Finance or e-mailing one or more users.
文档分类(document classification)是指基于文档的内容执行某种动作。此动作可以是赋予文档一个分类 ID(category ID),以方便今后的查找,也可以是将文档传送给某个用户。分类操作的结果是一组经过分类的文档。例如,现在有一系列新闻文章。用户可以定义一个规则(rule)表示金融类文章。此规则实质上是以金融为主题对文档进行的一个或多个查询。例如,规则可能是关于股票,债券,或收入的查询。如果文档满足某个分类的规则,应用程序将会执行某种操作,例如将文档标记为金融类,或将其发送给某个用户。
035 Clustering is the unsupervised division of patterns into groups. The interface lets users select the appropriate clustering algorithm. Each cluster contains a subset of documents of the collection. A document within a cluster is believed to be more similar with documents inside the cluster than with outside documents. Clusters can be used to build features like presenting similar documents in the collection.
聚类是一种基于模式(pattern)的无监督(unsupervised)分类方法。用户可以选择适当的聚类算法(clustering algorithm)。每个聚类包含文档集(documents of the collection)的一个子集。同一聚类内的文档相比其他聚类内的文档来说具有更大的相似性。聚类的作用是从文档集中找出相似性较高的文档。

See Also:

Oracle Text Application Developer's Guide


Oracle Text Application Developer's Guide

Overview of Oracle Ultra Search

19.5 Oracle Ultra Search 概述

038 Oracle Ultra Search is built on the Oracle database server and Oracle Text technology that provides uniform search-and-locate capabilities over multiple repositories: Oracle databases, other ODBC compliant databases, IMAP mail servers, HTML documents served up by a Web server, files on disk, and more.
Oracle Ultra Search 组件基于 Oracle 数据库及 Oracle Text 技术,提供了针对多种资源的统一的查询及定位能力,其可搜索的资源包括 Oracle 数据库,其他 ODBC 兼容数据库,IMAP 邮件服务器,Web 服务器中的 HTML 文档,及磁盘中的文件等。
039 Ultra Search uses a 'crawler' to index documents; the documents stay in their own repositories, and the crawled information is used to build an index that stays within your firewall in a designated Oracle database. Ultra Search also provides APIs for building content management solutions.
Ultra Search 组件使用爬虫(crawler)对文档进行索引。被索引的文档依旧存储在原来的位置,索引依据爬虫获取的信息建立,可以存储在防火墙内用户指定的 Oracle 数据库中。Ultra Search 组件还提供了构建内容管理系统所需的 API。
040 Ultra Search offers the following:
  • A complete text query language for text search inside the database
  • Full integration with the Oracle database server and the SQL query language
  • Advanced features like concept searching and theme analysis
  • Indexing of all common file formats (150+)
  • Full globalization, including support for Chinese, Japanese and Korean (CJK), and Unicode
Ultra Search 组件还具有以下特性:
  • 提供了用于在数据库内进行文本搜索(text search)的完整的文本查询语言(text query language)
  • 与 Oracle 数据库及 SQL 查询全面集成
  • 概念搜索(concept searching)及主题分析(theme analysis)等高级特性
  • 对所有常见格式的文档进行索引(超过 150 种)
  • 全球化支持,包括汉语,日语,韩语(CJK)及 Unicode

See Also:

Oracle Ultra Search Administrator's Guide


Oracle Ultra Search Administrator's Guide

Overview of Oracle interMedia

19.6 Oracle interMedia 概述

043 Oracle interMedia ("interMedia") is a feature that enables Oracle Database to store, manage, and retrieve images, audio, and video data in an integrated fashion with other enterprise information. Oracle interMedia extends Oracle Database reliability, availability, and data management to media content in traditional, Internet, electronic commerce, and media-rich applications.
Oracle interMedia 组件使 Oracle 数据库可以存储,管理,并查询图像,音频,及视频数据,且提供了与其他类型数据相集成的操作接口。Oracle interMedia 组件扩展了 Oracle 数据库在传统应用系统,Internet 系统,电子商务系统,及多媒体系统中的可靠性,可用性,及对多媒体数据的管理能力。
044 interMedia manages media content by providing the following:
  • Storage and retrieval of media data in the database to synchronize the media data with the associated business data
  • Support for popular image, audio, and video formats
  • Extraction of format and application metadata into XML documents
  • Full object and relational interfaces to interMedia services
  • Access through traditional and Web interfaces
  • Querying using associated relational data, extracted metadata, and media content with optional specialized indexing
  • Image processing, such as thumbnail generation
  • Delivery through RealNetworks and Windows Media Streaming Servers
interMedia 组件提供以下功能供用户管理多媒体数据:
  • 获取及存储数据库中的多媒体数据,使此类数据库与相关的业务数据同步
  • 支持常见的图像,音频,视频格式
  • 抽取多媒体数据的格式信息及元数据,并存储到 XML 文档中
  • 提供了针对多媒体数据的对象访问接口及关系型访问接口
  • 通过传统接口或 Web 接口访问数据
  • 对与多媒体数据相关的关系型数据,多媒体数据的元数据,多媒体数据自身进行查询,且可以创建多媒体数据专用索引
  • 图像处理功能,例如生成缩略图(thumbnail)
  • 通过 RealNetworks 及 Windows Media Streaming Servers 发布多媒体内容
045 interMedia provides media content services to Oracle JDeveloper 10g, Oracle Content Management SDK, Oracle Application Server Portal, Oracle applications, and Oracle partners.
interMedia 组件为 Oracle JDeveloper 10g,Oracle Content Management SDK,Oracle Application Server Portal,各种 Oracle 应用系统,及 Oracle 合作伙伴的第三方应用系统提供了多媒体数据操作接口。

See Also:



Overview of Oracle Spatial

19.7 Oracle Spatial 概述

048 Oracle Spatial is designed to make spatial data management easier and more natural to users of location-enabled applications and geographic information system (GIS) applications. When spatial data is stored in an Oracle database, it can be easily manipulated, retrieved, and related to all other data stored in the database.
Oracle Spatial 组件能够帮助位置应用系统(location-enabled application)或地理信息系统(geographic information system,GIS)的用户以更简单更自然的方式管理空间数据(spatial data)。把空间数据存储于 Oracle 数据库内,便于空间数据与数据库内的其他数据一同操作,一同查询,或进行关联。
049 A common example of spatial data can be seen in a road map. A road map is a two-dimensional object that contains points, lines, and polygons that can represent cities, roads, and political boundaries such as states or provinces. A road map is a visualization of geographic information. The location of cities, roads, and political boundaries that exist on the surface of the Earth are projected onto a two-dimensional display or piece of paper, preserving the relative positions and relative distances of the rendered objects.
道路图(road map)是一种常见的空间数据。道路图是一种二维对象,其中包含点,线,多边形以代表城市,道路,及省或州的行政区划边界。道路图是可视化的地理信息。实际的城市,道路,及行政区划边界被投影为二维的图形,保留了原来的相对位置及相对距离,并可进行显示或打印。
050 The data that indicates the Earth location (such as longitude and latitude) of these rendered objects is the spatial data. When the map is rendered, this spatial data is used to project the locations of the objects on a two-dimensional piece of paper. A GIS is often used to store, retrieve, and render this Earth-relative spatial data.
用于表示空间对象地标(例如经度和纬度)的数据就是空间数据。在生成可视化道路图时,需要利用空间数据将空间对象的位置投影到二维的平面上。GIS 系统通常用于存储,查询,及绘制空间信息。
051 Types of spatial data (other than GIS data) that can be stored using Spatial include data from computer-aided design (CAD) and computer-aided manufacturing (CAM) systems. Instead of operating on objects on a geographic scale, CAD/CAM systems work on a smaller scale, such as for an automobile engine or printed circuit boards.
Oracle Spatial 组件还可以存储另一类空间数据(不是 GIS 数据),主要用于 CAD(computer-aided design)及 CAM(computer-aided manufacturing)系统。CAD/CAM 系统与 GIS 系统相比,其中所管理的对象尺度更小,例如汽车引擎或印刷电路板等。
052 The differences among these systems are in the size and precision of the data, not the data's complexity. The systems might all involve the same number of data points. On a geographic scale, the location of a bridge can vary by a few tenths of an inch without causing any noticeable problems to the road builders, whereas if the diameter of an engine's pistons is off by a few tenths of an inch, the engine will not run.
CAD/CAM 系统与 GIS 系统所处理的数据的区别在于其规模与精度,而非数据的复杂性。两类系统需要处理的数据量可能相同。对于地理信息,一座桥梁的位置信息偏离十分之几英寸不会给施工带来显著问题。而对于 CAD/CAM 信息,如果引擎活塞的直径有十分之几英寸的偏差,引擎肯定无法工作。
053 In addition, the complexity of data is independent of the absolute scale of the area being represented. For example, a printed circuit board is likely to have many thousands of objects etched on its surface, containing in its small area information that may be more complex than the details shown on a road builder's blueprints.
054 These applications all store, retrieve, update, or query some collection of features that have both nonspatial and spatial attributes. Examples of nonspatial attributes are name, soil_type, landuse_classification, and part_number. The spatial attribute is a coordinate geometry, or vector-based representation of the shape of the feature.
055 Oracle Spatial provides a SQL schema and functions that facilitate the storage, retrieval, update, and query of collections of spatial features in an Oracle database. Spatial consists of the following:
  • A schema (MDSYS) that prescribes the storage, syntax, and semantics of supported geometric datatypes
  • A spatial indexing mechanism
  • Operators, functions, and procedures for performing area-of-interest queries, spatial join queries, and other spatial analysis operations
  • Functions and procedures for utility and tuning operations
  • Topology data model for working with data about nodes, edges, and faces in a topology.
  • Network data model for representing capabilities or objects that are modeled as nodes and links in a network.
  • GeoRaster, a feature that lets you store, index, query, analyze, and deliver GeoRaster data, that is, raster image and gridded data and its associated metadata.
Oracle Spatial 组件具有一个模式(schema)及一组函数,用于对 Oracle 数据库内的空间数据库进行存储,查询及更新。Oracle Spatial 组件包含以下特性:
  • 一个数据库模式(MDSYS),其中描述了 Oracle 支持的几何数据类型(geometric datatype)的存储结构,语法,及语义
  • 空间数据索引机制(spatial indexing mechanism)
  • 用于进行选定空间查询(area-of-interest query),空间关联查询(spatial join query),及其他空间分析操作的操作符,函数,及存储过程
  • 与空间操作及调优操作有关的函数及存储过程
  • 用于管理拓扑结构中的点,线,面的拓扑数据模型(topology data model)
  • 网络数据模型(network data model),用于展现网络模型中的节点和连接线
  • GeoRaster,供用户存储,索引,查询,分析,展现 GeoRaster 数据。GeoRaster 数据指光栅图像(raster image)与栅格数据(gridded data)及相关的元数据

See Also:

Oracle Spatial GeoRaster and Oracle Spatial Topology and Network Data Models


Oracle Spatial GeoRasterOracle Spatial Topology and Network Data Models

A 翻译不确定的词汇(格式:黄色背景 )  

[008] still video clips
[008] full motion video
[023] count hits
[025] routing applications
[028] Inso filtering technology
[034] earnings
[040] concept searching
[040] theme analysis
[048] location-enabled applications
[055] raster image
[055] gridded data

B 翻译不确定的Oracle/数据库词汇(格式:

[004] native types
[006] collections
[006] references

C 翻译不确定的句子(格式:

[023] Oracle Text can automatically create XML sections for you.
[034] Actions can be assigned category IDs to a document for future lookup or for sending a document to a user.
[055] Network data model for representing capabilities or objects that are modeled as nodes and links in a network.

D 注释性的文字(格式:


E 未完成的链接

[019] Overview of LOB Datatypes

F Oracle学习问题(格式:
1、replication 是 scalability 特性么?
[023] Oracle Text leverages scalability features, such as replication.

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