星期日, 3月 21, 2010

顯示卡對遊戲速度的影響

對於獨立顯示卡來說,每款遊戲對顯示卡記憶體的要求均有所不同。
一些較細緻的場景,如果記憶體不足,有可能會導致畫面緩慢的問題,而令遊戲未能順暢地運作。

星期六, 3月 20, 2010

Working in Lotus iNotes

1. Which of the following statements about the Lotus iNotes Sync Manager are true?

Choose more than one option.

It is installed every time you install a new subscription
You can use it to delete a subscription from your computer
You can use it to open the online or offline version of a subscription
You can use it to synchronize the online and offline versions of a subscription


2. Which of the following statements about accessing data using Lotus iNotes Web Access are correct?

Choose more than one option.

Access is dependent on your administrator loading additional software on your PC
You can access iNotes using a browser outside your organization
You can customize the Welcome page
You can link to your Notes client from iNotes Web Access




3. Which of the following can you use to access Lotus iNotes Web Access?

Choose an option.

An ID file
An IP address
A Notes client
Sametime



4. Which of the following statements about using Lotus iNotes Web Access to work offline are correct?

Choose more than one option.

All offline subscriptions are displayed by the iNotes Sync Manager
You have to create a new subscription to a database every time you want to access it online
You must install iNotes Offline software to be able to work offline
You need your ID file every time you want to install a new subscription

星期四, 3月 18, 2010

如何使用 plink 執行 script

相信大家也有使用過 putty 操控 linux server, 但如何利用 batch script 連接 linux ?
答案就是 plink.

首先以 notepad 輸入以下命令:

plink -ssh [host] -l [user] -pw [password]
如: plink -ssh 10.0.0.1 -l root -pw Passw0rd

然後另存為 abc.bat 放在 plink 的資料夾中便可

那如何執行 script ?
例如我希望 restart proxy server 的 dansguardian service, 那便...
plink -ssh 10.0.0.1 -l root -pw Passw0rd service dansguardian restart

亦可同時執行數個 command, 如:
plink -ssh 10.0.0.1 -l root -pw Passw0rd ls; service dansguardian restart
便會先執行 ls, 再執行 service dansguardian restart

那我們便可以用 task scheduler 排定工作了 ~

============================

PuTTY Link: command-line connection utility


Unidentified build, Nov 21 2005 12:41:01

Usage: plink [options] [user@]host [command]

("host" can also be a PuTTY saved session name)

Options:

-V print version information and exit

-pgpfp print PGP key fingerprints and exit

-v show verbose messages

-load sessname Load settings from saved session

-ssh -telnet -rlogin -raw

force use of a particular protocol

-P port connect to specified port

-l user connect with specified username

-batch disable all interactive prompts

The following options only apply to SSH connections:

-pw passw login with specified password

-D [listen-IP:]listen-port

Dynamic SOCKS-based port forwarding

-L [listen-IP:]listen-port:host:port

Forward local port to remote address

-R [listen-IP:]listen-port:host:port

Forward remote port to local address

-X -x enable / disable X11 forwarding

-A -a enable / disable agent forwarding

-t -T enable / disable pty allocation

-1 -2 force use of particular protocol version

-4 -6 force use of IPv4 or IPv6

-C enable compression

-i key private key file for authentication

-m file read remote command(s) from file

-s remote command is an SSH subsystem (SSH-2 only)

-N don't start a shell/command (SSH-2 only)

星期三, 3月 17, 2010

如何利用 command 遠端為電腦執行磁碟重組

條件: script 執行端已安裝 psexec

首先, 利用 command 為電腦執行磁碟重組我們可以用 defrag
如: defrag c: -f

那大量為電腦執行 defragment, 我們便可以...

start "pc01" psexec \\pc01 defrag c: -f
start "pc02" psexec \\pc02 defrag c: -f

如果對遠端電腦存取被拒, 可先使用 net use command, 如:
net use \\pc01 /user:domain\administrator password

星期一, 3月 15, 2010

cmd 亂碼

有時執行 cmd 時, 會發現有亂碼的情況

我們可以嘗試更改編碼以解決

方法一: 在命令提示字元中更改
























方法二: 在  registry 中更改



















方法三: 在  cmd 中更改





















字碼頁 國家 (地區) 或語言
437 美國
850 多語言系統 (拉丁 I)
852 斯拉夫文 (拉丁文 II)
855 古斯拉夫文 (俄文)
857 土耳其文
860 葡萄牙文
861 冰島文
863 加拿大法語區
865 日耳曼文
866 俄文
869 現代希臘文
65001 UTF-8

星期日, 3月 14, 2010

The Database Environment and Development Process

Objectives
  • Define terms
  • Name limitations of conventional file processing
  • Explain advantages of databases
  • Identify costs and risks of databases
  • List components of database environment
  • Identify categories of database applications
  • Describe database system development life cycle
  • Explain prototyping and agile development approaches
  • Explain roles of individuals
  • Explain the three-schema architecture for databases

 

 
Definitions
  • Database: organized collection of logically related data
  • Data: stored representations of meaningful objects and events
  • Structured: numbers, text, dates
  • Unstructured: images, video, documents
  • Information: data processed to increase knowledge in the person using the data
  • Metadata: data that describes the properties and context of user data

 

 

 
Disadvantages of File Processing
  • Program-Data Dependence
    • All programs maintain metadata for each file they use
  • Duplication of Data
    • Different systems/programs have separate copies of the same data
  • Limited Data Sharing
    • No centralized control of data
  • Lengthy Development Times
    • Programmers must design their own file formats
  • Excessive Program Maintenance
    • 80% of information systems budget

 

 

 
Problems with Data Dependency
  • Each application programmer must maintain his/her own data
  • Each application program needs to include code for the metadata of each file
  • Each application program must have its own processing routines for reading, inserting, updating, and deleting data
  • Lack of coordination and central control
  • Non-standard file formats

 

 

 
Problems with Data Redundancy
  • Waste of space to have duplicate data
  • Causes more maintenance headaches
  • The biggest problem:
    • Data changes in one file could cause inconsistencies
    • Compromises in data integrity

 

 

 
SOLUTION: The DATABASE Approach
  • Central repository of shared data
  • Data is managed by a controlling agent
  • Stored in a standardized, convenient form

 

 

 
Advantages of the Database Approach
  • Program-data independence
  • Planned data redundancy
  • Improved data consistency
  • Improved data sharing
  • Increased application development productivity
  • Enforcement of standards
  • Improved data quality
  • Improved data accessibility and responsiveness
  • Reduced program maintenance
  • Improved decision support

 

 

 
Costs and Risks of the Database Approach
  • New, specialized personnel
  • Installation and management cost and complexity
  • Conversion costs
  • Need for explicit backup and recovery
  • Organizational conflict

 

 

 
Elements of the Database Approach
  • Data models
    • Graphical system capturing nature and relationship of data
    • Enterprise Data Model–high-level entities and relationships for the organization
    • Project Data Model–more detailed view, matching data structure in database or data warehouse
  • Entities
    • Noun form describing a person, place, object, event, or concept
    • Composed of attributes
  • Relationships
    • Between entities
    • Usually one-to-many (1:M) or many-to-many (M:N)
  • Relational Databases
    • Database technology involving tables (relations) representing entities and primary/foreign keys representing relationships

 

 

 
Components of the Database Environment
  • CASE Tools–computer-aided software engineering
  • Repository–centralized storehouse of metadata
  • Database Management System (DBMS) –software for managing the database
  • Database–storehouse of the data
  • Application Programs–software using the data
  • User Interface–text and graphical displays to users
  • Data/Database Administrators–personnel responsible for maintaining the database
  • System Developers–personnel responsible for designing databases and software
  • End Users–people who use the applications and databases

 

 

 
The Range of Database Applications
  • Personal databases
  • Two-tier Client/Server databases
  • Multitier Client/Server databases
  • Enterprise applications
  • Enterprise resource planning (ERP) systems
  • Data warehousing implementations

 

 

 
Enterprise Database Applications
  • Enterprise Resource Planning (ERP)
    • Integrate all enterprise functions (manufacturing, finance, sales, marketing, inventory, accounting, human resources)
  • Data Warehouse
    • Integrated decision support system derived from various operational databases

 

 

 
Enterprise Data Model
  • First step in database development
  • Specifies scope and general content
  • Overall picture of organizational data at high level of abstraction
  • Entity-relationship diagram
  • Descriptions of entity types
  • Relationships between entities
  • Business rules

 

 

 
Two Approaches to Database and IS Development
  • SDLC
    • System Development Life Cycle
    • Detailed, well-planned development process
    • Time-consuming, but comprehensive
    • Long development cycle
  • Prototyping
    • Rapid application development (RAD)
    • Cursory attempt at conceptual data modeling
    • Define database during development of initial prototype
    • Repeat implementation and maintenance activities with new prototype versions

 

 

 
Database Schema
  • External Schema
    • User Views
    • Subsets of Conceptual Schema
    • Can be determined from business-function/data entity matrices
    • DBA determines schema for different users
  • Conceptual Schema
    • E-R models
  • Internal Schema
    • Logical structures
    • Physical structures
         

 

 

 
Managing Projects
  • Project–a planned undertaking of related activities to reach an objective that has a beginning and an end
  • Involves use of review points for:
    • Validation of satisfactory progress
    • Step back from detail to overall view
    • Renew commitment of stakeholders
  • Incremental commitment–review of systems development project after each development phase with rejustification after each phase

 

 

 
Managing Projects: People Involved
  • Business analysts
  • Systems analysts
  • Database analysts and data modelers
  • Users
  • Programmers
  • Database architects
  • Data administrators
  • Project managers
  • Other technical experts

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