Oracle Database - Database

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1 - About

A database in the context of Oracle is a collection of files (physical structures):

  • data files,
  • control files,
  • redo log files

A database may be mounted and opened by many instances.

This physical structures contain logical structures:

  • tablespaces,
  • schema objects,
  • data blocks,
  • extents,
  • and segments.

Because the physical and logical structures are separate, the physical storage of data can be managed without affecting the access to logical storage structures.

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3 - Data Dictionary

SELECT   
   db_unique_name,
   database_role,
   open_mode
FROM      
   v$database

4 - Status / Open

SQL> SELECT status FROM v$instance;
 
STATUS
------------
MOUNTED
 
SQL> ALTER database OPEN;
 
Database altered.

alter database

db/oracle/database.txt · Last modified: 2017/09/06 19:27 by gerardnico