Research on the relationship between users and table spaces in Oracle

Exploration on the relationship between users and tablespaces in Oracle

In the Oracle database, there is a close relationship between the user (User) and the tablespace (Tablespace). Users are operators in the database, and table spaces are logical structures used to store user data and indexes. The relationship between users and table spaces is an important concept in database management, which is related to data storage, management and security.

1. Creation of User (User) and associated table space

In Oracle, we can create a new user through the following SQL statement and specify the table space used by the user:

CREATE USER new_user IDENTIFIED BY password DEFAULT TABLESPACE users TEMPORARY TABLESPACE temp;

In this example, we created a user named new_user, specified the user's password as password, and assigned it a default table space of users and a temporary table space of temp. The selection of table space can be adjusted according to actual needs.

2. View the table space used by the user

To view the table space used by the user, you can use the following SQL statement:

SELECT username, default_tablespace, temporary_tablespace
FROM dba_users
WHERE username = 'new_user';

This SQL statement will return the new_user user Default tablespace and temporary tablespace information.

3. Modify the user’s table space

If you need to modify the user’s table space, you can use the following SQL statement:

ALTER USER new_user DEFAULT TABLESPACE new_tablespace TEMPORARY TABLESPACE temp;

Through this SQL statement, we will change the new_user user The default tablespace is changed to new_tablespace. The temporary tablespace remains temp.

4. Creation and Management of Table Spaces

In addition to user-associated table spaces, you also need to know how to create and manage table spaces. The following is an example of creating a new table space:

CREATE TABLESPACE new_tablespace
DATAFILE 'new_tablespace.dbf' SIZE 100M
AUTOEXTEND ON NEXT 10M MAXSIZE UNLIMITED;

In this example, we create a table space named new_tablespace, specify the size of the data file new_tablespace.dbf as 100M, and set automatic expansion. The maximum size is unlimited.

5. View all table spaces in the database

To view all table spaces in the database, you can use the following SQL statement:

SELECT tablespace_name
FROM dba_tablespaces;

This SQL statement will return all tables A list of names for spaces.

Through the above sample code and operations, we have a deeper understanding of the relationship between users and table spaces in Oracle. For database managers, an in-depth understanding of the relationship between users and table spaces will help manage the database more effectively and improve database performance and security.

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