Anonymous
Anonymous asked in 社會及文化語言 · 5 years ago

翻譯(不要GOOGLE翻譯)X2

1.2 数据库与实例

数据库是一个具体的概念, 它指的是数据库厂家提供的使数据库运行的程序和用户用此程序创建的数据库文件以及参数文件. 这些文件是死的东西. 我们不能通过这些程序来达到我们存取数据的目的. 所以就引出了实例的概念.

实例是指由数据库程序启动的一些进程和系统为数据库运行而分配的一些内存结构. Oracle的内存结构称为SGA(System Global Area), 它是由以下几个部分组成:

数据库高速缓存区

共享池

redo日志缓存器

大缓存池

固定SGA

在SGA中适当地设定结构的大小对于数据库的性能是绝对重要的. 可以通过调整

init.ora参数文件来调整系统的SGA结构

Oracle通过一组后台进程来管理数据库系统的运行. 这组后台进程如下:

DBW0 数据库书写器进程

LGWR 日志书写器进程

SMON 系统监视器进程

PMON 进程监视器进程

REC0 恢复器进程

SNP0 抽点打印进程

QMN0 队列监视进程

LCK0 锁进程

CKPT 检查点进程

ARC0 归档进程

对于Oracle来说, 有些进程是可选的, 如SNP0进程.

以上SGA和进程组成了Oracle的实例. 远端客户端便可通过Net8(Oracle的网络软件)

和这个实例进行连接, 从而在远端使用数据库的功能.

3 Answers

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  • 5 years ago
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    1.2 databases and instances

    Database is a specific concept, it refers to the database provided by the manufacturer of the database program running and user database files created using this program and parameter file. These files are dead things. Through these programs we can't access data to achieve our purpose. Therefore leads to a instance of concepts.

    Instance refers to processes started by a database program and run some memory allocated for the database structure of the system. Oracle memory structures called the SGA (System Global Area), which is composed of the following parts:

    Database cache

    Shared pool

    Redo log buffer

    Buffer pool

    Fixed SGA

    Appropriate to set the size of the structure in the SGA for database performance is absolutely essential. You can adjust the

    Init.ora parameter file to adjust the system's SGA structures

    Oracle Management database system through a set of background processes to run. This set of background processes are as follows:

    The DBW0 database writer processes

    Log writer process LGWR

    SMON system monitor process

    PMON process monitor process

    REC0 recovery process

    SNP0 snapshot process

    QMN0 queue monitor processes

    LCK0 locking process

    CKPT checkpoint process

    ARC0 archive process

    For Oracle, and some processes are optional, such as the SNP0 process.

    Above SGA and process to form the Oracle instance. Remote clients via Net8 (Oracle networking software)

    And this instance to connect to remote database functionality.

    Source(s): ME
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  • 5 years ago

    1.2 Database and examples

    The database is a concrete concept, it refers to the database

    manufacturers provide the procedures and run the database files

    and parameter files with this program created by the user.

    These files are the fixed things. We cannot achieve the purpose of

    data access though these programs, so it leads to the concrete

    concept to illustrate the examples.

    The example is a process started by some of the database program,

    and some memory structure was allocated by system running the

    database.

    Oracle's memory structure was called SGA (System Global Area),

    which was composed by following parts:

    Database cache area

    Shared pool

    Redo log buffer

    Large cache pool

    Fixed SGA

    In the SGA, the appropriately setting of the structure size was

    absolutely essential to the performance of the database, that which

    can be adjusted.

    The init.ora parameter file was used to adjust the structure of SGA,

    Oracle through a set of processes to manage and run the database

    system.

    This set of background processes as follows:

    DBW0 database writer process

    LGWR Log Writer process

    SMON System Monitor Process

    PMON Process Monitor Process

    REC0 The recovery process

    SNP0 snapshot process

    QMN0 queue monitor process

    LCK0 lock process

    CKPT checkpoint process

    ARC0 archiving process

    For Oracle, some processes are optional, as SNP0 process.

    SGA and process above was composed an example of Oracle.

    Distal client can access the function of database through the

    Net8 (Oracle network software) and this example was connected.

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  • 5 years ago

    可以用 Google 翻譯

    Source(s): 自己
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