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<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html><head><meta name="generator" content="HTML Tidy for Linux/x86 (vers 1 September 2005), see www.w3.org"><meta http-equiv="content-type" content="text/html; charset=us-ascii"><meta name="Generator" content="Microsoft Word 97"><title>db.* User's Guide Chapter 1</title></head><body><h1><a name="Introduction" id="Introduction"></a>Chapter 1<br>Introduction</h1><h2><a name="Overview" id="Overview"></a>1.1 Overview</h2><p><font size="2">The <b><i>db.*</i></b> database management system(DBMS) is designed to provide powerful, flexible, high-performancecapabilities for developing C language database applications. Bycombining the network and relational model technologies in a singlesystem, <b><i>db.*</i></b> lets you organize and access informationefficiently, regardless of the complexity of your data. Thiscombined technology provides tremendous speed advantages, andminimizes data redundancy.</font></p><p>The <b><i>db.*</i></b> DBMS is written in C, so the applicationsyou create with it are easily ported to a variety of operatingsystems, including Linux, UNIX, and Windows. The potential marketfor your applications spans from one-user microcomputers and LANs,to minis and mainframes. Since you have complete source code youhave full control over any application you create.</p><p>The major features of <b><i>db.*</i></b> include:</p><ul><li>Multi-user support for local-area networks (LANs) andmulti-user computers.</li><li>Transaction processing and logging.</li><li>Automatic database recovery.</li><li>Access methods based on the network and relational databasemodels.</li><li>A Database Definition Language patterned after C, for definingthe content and structure of a <b><i>db.*</i></b> database.</li><li>Multiple database access. More than one database can be openedand accessed at a time from an application program.</li><li>Incremental opens and closes of multiple databases.</li><li>Interactive and batch database access utilities, for easymanipulation of the information in a <b><i>db.*</i></b>database.</li><li>File transfer utilities for importing and exporting databetween ASCII text files and a <b><i>db.*</i></b> database.</li><li>Ability to use multiple volumes for data storage.</li><li>A database consistency check utility for reporting any problemswith database integrity.</li><li>Virtual memory disk caching, for fast database access.</li><li>A runtime library of over 150 functions, for complete databasecontrol.</li><li>Royalty-free runtime distribution.<br></li></ul><h2><a name="Documentation" id="Documentation"></a>1.2 <i>db.*</i>Documentation</h2><p><font size="2">The <b><i>db.*</i></b> documentation is athree-manual set and includes this <i>User's Guide</i>, the<b><i>db.*</i> Reference Manual</b> and the <b><i>db.*</i></b><i>Multi-User Guide</i>. The full set is provided in HTML formattogether with the source code, and on the community host web site.This volume, the <b><i>db.*</i> User's Guide</b>, contains generalinformation and examples on the use of the system.</font></p><h3><a name="About" id="About"></a>1.2.1 About This Manual</h3><p><font size="2">The <i>User's Guide</i> is organized as describedbelow.</font></p><p>Chapter 1 is introductory.</p><p>Chapter 2, "Database Concepts," should be read by everyone,regardless of the extent of their database background. It presentsbasic <b><i>db.*</i></b> database concepts, such as definitions ofthe database terminology used in this manual, a description of thenetwork database model and the differences between it and therelational model, and an explanation of the elements of a<b><i>db.*</i></b> database.</p><p>Chapter 3, "Operational Overview," gives an overview of each ofthe components of a <b><i>db.*</i></b> DBMS. It describes thegeneral operational flow for creating a <b><i>db.*</i></b>application program, and provides a simple (but complete)introductory example.</p><p>Chapter 4, "Database Design," describes in detail<b><i>db.*</i></b>'s Database Definition Language (DDL) and theoperation of the DDL processor. It also explains how to design a<b><i>db.*</i></b> database, and includes an example of databasedesign that illustrates some of the more commonly usedstructures.</p><p>Chapter 5, "Database Manipulation," explains the use of<b><i>db.*</i></b> runtime functions for controlling, accessing,and manipulating a database from a C application program.</p><p>Chapter 6, "Transaction Processing," describes transactionprocessing functions and tells you how to use transactions in asingle- or multi-user environment. This chapter will help youdesign transactions that meet the needs of your application.</p><p>Chapter 7, "Multi-User Database Control," describes the use of<b><i>db.*</i></b> in multi-user, shared database applications.Basic multi-user concepts are presented, as is a detaileddescription of <b><i>db.*</i></b>'s multi-user implementation.Chapter 7 also explains how to use the runtime multi-user controlfunctions to efficiently synchronize shared database access.</p><p>Chapter 8, "Unicode and <b><i>db.*</i></b>" explains the use ofthe Unicode feature and how <b><i>db.*</i></b> incorporates thischaracter encoding standard.</p><p>Chapter 9, "Interactive Database Access Utility (<b>ida</b>),"provides complete information on the use of the command line<b>ida</b> utility for UNIX users</p><p>Chapter 10, "File Transfer Utilities (<b>dbimp</b> and<b>dbexp</b>)," describes the utilities used for transferring databetween a <b><i>db.*</i></b> database and ASCII text.</p><p>Chapter 11, "Database Access Language (<b>dal</b>)," describes atool for accessing a database interactively or in batch mode. daluses the <b><i>db.*</i></b> runtime library functions, plus a fewinformation and control commands. It is an excellent educationaltool.</p><p>Chapter 12, "Database Editor (<b>dbedit</b>)," contains adescription of the low-level database editing utility, which allowsviewing and changing a database at the "bits and bytes" level. Thedatabase editor is the ultimate database repair program.</p><p>Chapter 13, "Maintenance Utilities," provides information on theuse of the following utilities: database initialization utility(<b>initdb</b>), database consistency check utility(<b>dbcheck</b>), delete chain sort utility (<b>dchain</b>), keyfile build utility (<b>keybuild</b>), dictionary print utility(<b>prdbd</b>), formatted data file dump utility (<b>datdump</b>),key file packing utility (<b>keypack</b>), formatted key file dumputility (<b>keydump</b>), and the clear lock bit utility(<b>dbclrlb</b>).</p><p>Chapter 14, "File Formats and Dictionary Tables," providesdetailed information on <b><i>db.*</i></b> data and key files, andon the structure and organization of the <b><i>db.*</i></b>dictionary.</p><p>The Glossary defines a number of database terms used in thismanual and the other books of the <b><i>db.*</i></b> set.</p><h3><a name="Documents" id="Documents"></a>1.2.2 Related<i>db.*</i> Documents</h3><p><font size="2">The <b><i>db.*</i> Reference Manual</b> containsdetailed descriptions of <b><i>db.*</i></b> API functions, functionprototypes, utilities, and return codes and errormessages.</font></p><p>The <b><i>db.*</i> Multi-User Guide</b> describes operation ofthe lock manager (a centralized file lock and recovery manager) andprovides details about the various operating environments supportedby this release.</p><h3><a name="Conventions" id="Conventions"></a>1.2.3 DocumentConventions</h3><p><font size="2">Table 1-1 describes the notational conventionsused in this guide.</font></p><p align="center"><b>Table 1-1. Document NotationalConventions</b></p><table cellspacing="0" border="0" cellpadding="7" width="535"><tr><td width="37%" valign="top"><p><b><font size="2">Convention</font></b></p></td><td width="63%" valign="top"><p><b><font size="2">Description</font></b></p></td></tr><tr><td width="37%" valign="top"><p><b><font size="2">Bold Text</font></b></p></td><td width="63%" valign="top"><p><font size="2">Indicates the names of functions, commands, datastructures, statements, databases, utilities, files, etc. Note thatthe case distinctions used in the names are not significant for alloperating systems.</font></p></td></tr><tr><td width="37%" valign="top"><p><i><font size="2">Italic Text</font></i></p></td><td width="63%" valign="top"><p><font size="2">Represents the names of variables, such asparameters and command options. The <i>db.*</i> documents also useitalics for the names of books.</font></p></td></tr><tr><td width="37%" valign="top"><p><font face="Courier" size="2" color="#0000FF">Courier, ColoredText</font></p></td><td width="63%" valign="top"><p><font size="2">Indicates a programming example, a command lineentry, or a utility menu.</font></p></td></tr><tr><td width="37%" valign="top"><p><font size="2">Brackets ([ ])</font></p></td><td width="63%" valign="top"><p><font size="2">Indicate optional fields or parameters in commandlines and syntax statements.</font></p></td></tr><tr><td width="37%" valign="top"><p><font size="2">Bar Symbol (|)</font></p></td><td width="63%" valign="top"><p><font size="2">Separates alternative selections. You shouldenter one of the items separated by the bar.</font></p></td></tr><tr><td width="37%" valign="top"><p><font size="2">Ellipsis (...)</font></p></td><td width="63%" valign="top"><p><font size="2">Indicates that you can repeat the preceding item.Both horizontal and vertical ellipses are used in programmingexamples to indicate omitted code.</font></p></td></tr><tr><td width="37%" valign="top"><p><font size="2">Arrow Symbols (< >)</font></p></td><td width="63%" valign="top"><p><font size="2">Indicate information that you must supply. Forexample, <filename>.h represents a header file that you name.Arrow symbols are also used in text to set off keyboard key names,as in <Ctrl>.</font></p></td></tr></table><h2><a name="Resources" id="Resources"></a>1.3 Other HelpfulResources</h2><p><font size="2"><font size="2">Worldwide Web</font><br>Further documentation and online forums discussing<b><i>db.*</i></b> are available on ITTIA's home page located at<a href="http://www.ittia.com">http://www.ittia.com</a>.</font></p><p><a href="UG_Ch2.htm">Next Page</a></p></body></html>⌨️ 快捷键说明
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