Thursday, March 22, 2007

Oracle9i DBA -- Database: Fundamentals I (2)

Getting Started with Oracle Server
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  • According to Oracle’s recommended approach, the first task that the DBA has to perform is evaluation of the server hardware.
  • The default initialization file is created in the ORACLE_BASE/admin/pfile
  • Using Oracle in a non-interactive mode is runInstaller –responsefile -silent
  • The SYSTEM user is used to create the internal views used by various Oracle tools
  • Before starting the DBCA the user accounts should either be locked or if that is not done then the accounts should be assigned new passwords.


Oracle9i DBA -- Database: Fundamentals I (1)

Oracle Architectural Components
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  • OSDBA groups allows its members to connect to 9i using the SYSDBA privileg0065
  • Tablespace -> Segment -> Extent -> DB blocks
  • The value of ORACLE_HOME are represented using ‘?’ symbol.
  • The SGA_MAX_SIZE is used to specify the max size of the SGA.
  • The share pool consists of the most recently executed SQL statements and the most recently used data definitions. The Database Buffer Cache contains copies of the database files, the redo log buffer records all changes made to the database blocks and the Program Global Area contains the data and control information for single server process or single background process.
  • The data dictionary cache is also referred to as the dictionary cache or row cache.
  • The database buffer cache stores copies of data blocks that have been retrieved from the data files. Consists of independent sub-caches:

    1. DB_CACHE_SIZE : Sizes the default buffer cache size only, it always exists and cannot be set to zero. Size of the buffer cache in Oracle SGA.

    2. DB_KEEP_CACHE_SIZE : Sizes the keep buffer cache, which is used to retain blocks in memory that are likely to be reused.

    3. DB_RECYCLE_CACHE_SIZE : Sizes the recycle buffer cache, which is used to eliminate blocks from memory that have little change of being reused.

  • DB_BLOCK_BUFFERS : Number of blocks cached in the SGA
  • The size of each buffer in the buffer cache is equal to the size of an Oracle block, and it is specified by the DB_BLOCK_SIZE parameter. The database buffer cache consists of independent sub-caches for buffer pools and for multiple block sizes. The parameter DB_BLOCK_SIZE determines the primary block size, which is used for the SYSTEM tablespace.
  • Diagnostic files contain information about significant events encountered while the instance is operational.

    1. alertSID.log file

    2. Background trace files : Vital information when background processes, such as SMON, PMON, DBWn, and others fail.

    3. User trace files : Vital information for fatal user errors or user forced traced files.

  • The minimum SGA configuration is three granules (one granule for fixed SGA (includes redo buffers; one granule for buffer cache; one granule for shared pool).

Oracle9i DBA -- Database: Fundamentals I (1Z0-031)

Oracle 9i DBA 認證考試 -- Database: Fundamentals I (1Z0-031)

要成為 Oracle 9i OCA 必須通過此門考試, 但此門考試是 DBA 認證考試中最簡單的一個考試, 當初去考試的時候約30分鐘就做完了~~ 隨後幾篇是當初準備考試的筆記, 大概念完就可以去考了~^Q^

以下是此門考試的內容:
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  • Oracle Architectural Components
  • Getting Started with Oracle Server
  • Managing an Oracle Instance
  • Creating a Database
  • Data Dictionary Content and Usage
  • Maintaining the Control File
  • Maintaining Redo Log Files
  • Managing Tablespace and Datafiles
  • Storage Structure and Relationships
  • Managing Undo Data
  • Managing Tables
  • Managing Indexes
  • Maintaining Data Integrity
  • Managing Password Security and Resources
  • Managing Users
  • Managing Privileges
  • Managing Roles
  • Using Globalization Support
  • Auditing
  • Loading data into a database
  • Other

Wednesday, March 21, 2007

Command and Conquer 3 will out at 3/26 !!!!

CnC 3 將在下周一上市.... 天阿~~ 幾乎已經沒在玩遊戲的我看到這消息也突然間激動了起來.
目前已經出了 Demo 版可以試玩, 試玩版包含一個教學,兩個關卡與一個對戰地圖. 試玩了一會,以前用的招數在這一代依然可以使用, 雖是一款新遊戲,但玩起來真是懷念阿~~~

以下是遊戲中幾個畫面, 期待下周的正式版~
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(久違了~~GDI~~~~)


(躲在碉堡裡打敵人~ 這是一定要的啦~~~~)



(C&C系列一定會有的精彩過場動畫~畫面又更精緻了~科技進步阿~~~~)


(選關的世界地圖也更漂亮了~~~希望關卡是從南極打到北極~~)

浪費我時間的 Wordpress

首先聲明: 不是 wordpress 不好用, 其實是我在要用Wordpress 時沒先搞清楚是什麼東西, 等都裝好了設好了才覺得不適合我使用, 浪費了我的時間了解這東西.

第一: 這是給要自行架設blog的人用的, 所以用別人架好的blog寫文章的人(如我)就不適用了
第二: 要裝wordpress時, 你要準備好能執行 PHP 的環境與安裝或找個MYSQL資料庫, 連名稱都看不懂的人(如很多人...)也就不適用了
第三: 就算會使用PHP與MYSQL, 但要找台電腦來裝這些, 還要隨時Online, 這也不是一般人可以做得到的, 雖然用 Google 搜尋會發現不少免費的, 但是你要有心理準備這些站不穩或是掛掉讓你心血全沒的打算. 那還是算了吧......

結論, 下次想裝一個別人都說好用的東西之前, 還是得先仔細看看這碗糕到底適不適合自己的需求,以免浪費寶貴時間.

Tuesday, March 20, 2007

Google + wikipedia = googlepedia

googlepedia 這是一個不錯的 firefox plugin

在google 的搜尋界面上, 搜尋結果也會同步顯是在 wikipedia 上的搜尋結果
如圖:

Google ig - Select Theme !!

Google ig 出現了一個新功能, 選擇佈景(Theme),

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(在圖片右下角)

總共有7種不同的佈景主題可以選, 而且每種佈景隨著時間變化會出現不同的圖樣



比較機車的一點是, 你必須將「語言偏好設定」改成不是「繁體中文」,像我是改成「English」, 這樣這個新功能就會出現了~~

XBMC 選擇字幕

XBMC 在這一版本可以自由的選擇字幕檔, 不用再像以前一定要將字幕檔名與影片檔名
編成同樣名稱. eg: 字幕檔名為 abc.srt . 影片檔名為 abc.avi
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方法如下:

1. 在撥放影片時, 選擇 start 鍵.
2. 選擇 聲音圖示
3. 就會出現"字幕"與"選擇字幕.... "兩各項目
4. "字幕'' 選擇上下鍵就可選擇不同語言的字幕, 如你在電腦用mplayer2觀看一樣
5. "選擇字幕.... " 就會出現檔案目錄讓你選擇你要的字幕檔案

ps. 還可以選擇壓縮檔內的字幕檔, 有機會在試看看此功能....