gs1-128 generator excel This page is intentionally left blank in Software

Maker QR Code ISO/IEC18004 in Software This page is intentionally left blank

This page is intentionally left blank
QR-Code Encoder In None
Using Barcode creator for Software Control to generate, create QR Code ISO/IEC18004 image in Software applications.
Quick Response Code Recognizer In None
Using Barcode recognizer for Software Control to read, scan read, scan image in Software applications.
(page 543)
Generate QR-Code In Visual C#
Using Barcode maker for .NET Control to generate, create QR Code image in .NET framework applications.
QR Code Generation In VS .NET
Using Barcode printer for ASP.NET Control to generate, create Quick Response Code image in ASP.NET applications.
11
QR Code Creator In .NET
Using Barcode encoder for .NET Control to generate, create QR Code image in Visual Studio .NET applications.
Generate QR In Visual Basic .NET
Using Barcode drawer for VS .NET Control to generate, create QR image in .NET framework applications.
Methods to Gain Reliability
Drawing Code 128C In None
Using Barcode drawer for Software Control to generate, create Code 128 Code Set C image in Software applications.
Code 39 Full ASCII Creation In None
Using Barcode creator for Software Control to generate, create Code 39 Extended image in Software applications.
As far as we know, our computer has never had an undetected error Conrad H Weisert Union Carbide Corporation
Encode EAN 128 In None
Using Barcode creation for Software Control to generate, create GS1 128 image in Software applications.
GTIN - 12 Encoder In None
Using Barcode drawer for Software Control to generate, create UPC-A image in Software applications.
This, and the two chapters which follow, discuss the areas that, in combination, are concerned with the security of database systems The term security is used here to describe the protection of systems and their contents from destruction The term security has often been used in a more narrow sense, but with a scope that varies from discussion to discussion We will not cover the aspects of security which concern themselves with issues of building and personnel security, although it is obvious that without physical security most computer-system oriented e orts can be brought to naught If we wish to secure a database, we will need to achieve a reliable and predictable mode of operation; we also have to provide a protection mechanism to achieve the desired control of access to the data Finally, we have to assure that there will be no destructive interference as multiple users share access to the database 543
EAN-13 Supplement 5 Generator In None
Using Barcode generation for Software Control to generate, create EAN-13 image in Software applications.
Bar Code Generator In None
Using Barcode printer for Software Control to generate, create barcode image in Software applications.
Methods to Gain Reliability
Make Identcode In None
Using Barcode creator for Software Control to generate, create Identcode image in Software applications.
Painting Barcode In None
Using Barcode encoder for Microsoft Excel Control to generate, create barcode image in Excel applications.
These three issues of security are presented in Chaps 11, 12, and 13: Reliability: improving the probability that the system does what it is instructed to do Protection: understanding, organizing, and controlling access to data in accordance with speci ed rights Integrity: maintenance of security in a system where multiple users are permitted to access the system and share the database There is clearly a strong interrelation among these areas The partitioning is chosen to simplify the presentation Some general issues on cost and bene ts related to security problems will be discussed in Chap 12 on the protection of data
Printing GS1 - 12 In None
Using Barcode maker for Font Control to generate, create UCC - 12 image in Font applications.
Make UPC Symbol In None
Using Barcode creator for Office Excel Control to generate, create UPC Symbol image in Microsoft Excel applications.
11-1
EAN13 Drawer In None
Using Barcode encoder for Excel Control to generate, create EAN13 image in Office Excel applications.
Paint Bar Code In Visual Studio .NET
Using Barcode maker for .NET framework Control to generate, create bar code image in .NET applications.
RELIABILITY
Creating EAN-13 Supplement 5 In None
Using Barcode generation for Online Control to generate, create GS1 - 13 image in Online applications.
USS Code 39 Printer In None
Using Barcode creator for Microsoft Word Control to generate, create Code 39 Extended image in Office Word applications.
Reliability is achieved when a computer system, both hardware and software, always produces correct results One obvious problem is the determination of correctness We use the term fault to denote the cause, and the word error for the manifestation of a fault Lack of correctness is demonstrated by the occurrence of an error Hardware, database design, programs, and data input mechanisms all contain faults Program faults or bugs are familiar to us all
Current methods of program debugging by testing are clearly inadequate, since they are typically limited to the veri cation of a few sample computations Analysis of the program structure can create a test plan which assures that each program section is executed once, but testing of every possible execution sequence is rarely feasible, since the number of combinations is nearly always too large Extreme values of input data can often induce errors and are useful in testing The application of structured programming techniques should lead to a reduction and better identi cation of bugs but will still not eliminate them Formal veri cation of programs attempts to eliminate faults These techniques depend on a detailed speci cation of the data transforms, and here a comprehensive database model is essential
We will not discuss the important speci c issue of program faults further but will concentrate on methods to deal with all kinds of faults found in databases Procedures of integrity monitoring (Sec 13-3) can also help in the maintenance of database reliability In order to produce correct results, we need correct data and correct algorithms, and the system has to carry out the algorithms correctly In each of these areas the problem reduces to two subproblems: 1 The existence of a fault has to be detected, or the absence of faults has to be proved 2 When an error is detected, a means of correcting and recovering from the error has to be available Frequently, a single technique may provide both detection and also some restoration capability We will discuss some common techniques in the light of these two aspects and then evaluate how these methods may be combined into a system that will have desirable characteristics
Sec 11-1
Copyright © OnBarcode.com . All rights reserved.