Learning from Oracle

Default User of Oracle: System,sys,scott;

1: View login username: Show user;

2: View data dictionary: dba_users;

3: Table Space Overview: Logical storage space for the database;

　　Data dictionary is a database provided by the table, the user to view the database information, the table space can be understood as a space opened in the database, for storing the database object, a database can be composed of multiple table space;

The relationship between a tablespace and a data file: A tablespace is actually composed of one or more data files.

Table Space Classification:

(1): Permanent table space: permanently stored tables/views, etc.;
(2): Temporary table space: Database operations in the middle of the process, the execution of the self-deletion will not be permanently saved;
(3): Undo Table Space: Save the old value of the transaction changes, the data before the modification (to facilitate the revocation and other convenient rollback);

4: View the user's tablespace;

Dba_tablespaces,user_tablespaces data dictionary;

Dba_users,user_users data dictionary;

5: Create, modify, delete table space;

Learning from Oracle