"Turn" Oracle infrastructure cognition-the first knowledge of Oracle's rites Eight mesh 2017-12-12 21:19:30

Oracle Servers (Oracle server) are comprised of instances and databases. The example is the so-called Relational database management system (relational Management System,rdbms), which is used to provide relevant database management functions, and the database is composed of Oracle database files, which is used to store the data. Instances can be further subdivided into system global AREA,SGA and background processes (Background Processes). The database can also be subdivided into data files, control files, and online redo log files (online Redo log file). Where the SGA of an instance is using the operating system's memory space, the background process needs to use CPU and memory resources, and the database file is stored on the hard disk. Reliably managing large amounts of data in a multi-user access Data environment and allowing multiple users to access the same data, all of which must be done while providing high performance. An Oracle server must also prevent unauthorized access and provide effective resolution of recovery.

Oracle Database Oracle Database provides actual physical storage database information by operating system files, also known as database files. Database files are used to ensure that the data is consistent and can be recovered in the case of a failure.

An Oracle instance (Oracle instance) consists of a background process and a memory structure (SGA) that is used to contact the operating system, meaning that the interaction between the database and the operating system uses a DB instance. The database name and instance name can be the same or different. In general, the instance name and database name are a one-to-many relationship, but if the database name and instance name are a one-to-much relationship in the Oracle Parallel server architecture (that is, Oracle real-time application cluster). The DB instance name and Oracle_sid both represent Oracle instances, but there are differences. Instance_name is an Oracle database parameter. ORACLE_SID is an environment variable for the operating system. Oracld_sid is used to interact with the operating system, that is, to access the instance name from the operating system's perspective and must pass ORACLE_SID.

manipulating Databases * * *

1. Connect to Database: Sqlplus "/as sysdba"

Oracle View DB Instance

2. Stop database: Shutdown immediate

3. Start the DB instance (instance): Startup Nomount

4. Start the database, then read the control file: Alter DATABASE mount;

5. Open the database service, actually completed the data file and log file verification: Alter DATABASE open;

6. Direct Load Startup: Startup

Oracle Boot Mount Database

System Global area***

Instance--memory structure (shared pool [library Cache,data dictionary cache],database buffer cache,redo log buffer cache)

Background process (pmon,smon,dbwr,lgwr,ckpt,others)

Database--data file

Log file

Control file

Dictionary Cache=row Cache

* A database can have multiple instances, and one instance can operate only one database.

* View Background process

Set Wrap Off

Set Linesize 200;

Col name for A30

Select * from V$bgprocess;

Select * from v$bgprocess wehre paddr <> ' 00 ';

*parameter Process:pmon,smon,lgwr,dbwn,ckpt,reco

*optional Process: no Elaboration

* View Log files

1. View the control file: SELECT * from V$controlfile;

2. View data file: SELECT * from V$datafile;

3. View the log file: SELECT * from V$logfile;

* View shared pools: Show parameter Gkfx

* View data cache: Show parameter Db_cache

* View Log cache: Show parameter log

* View SGA Size: Show Parmeter SGA

* Adjust Db_cache:alter system set db_cache_size=64m;

* Modify session Language tip: Alter session set Nls_language=american;

* View DB related parameters: Show parameter db

View Oracle Database Parameters

* About Db_cache Modify the relevant parameters: Alter system set db_cache_advice=on;

* View Large_pool_cache size: Show parameter large

* Modify Large_pool Size: Alter system large_pool_size=20m;

* View Oracle Archive mode: Archive Log list

* View Oracle Archive log parameters: Show parameter Log_archive_dest

* View the path of Oracle archive log: Show parameter db_recovery_file_dest

* View the Oracle database with administrator privileges: select * from V$pwfile_users;

* Creating Backup Pfile Files: Create spfile= '/databack/files/spfile.ora ' from pfile;

* Creating Backup SPFile Files: Create pfile= '/dadaback/files/init.ora ' from SPFile;

* View the number of database file types: Show parameter db_create

"Turn" Oracle infrastructure cognition-the first knowledge of Oracle's rites Eight mesh 2017-12-12 21:19:30