Oracle views users, user permissions, user tablespace, and user default tablespace

View the relationship between the user and the default tablespace.
Select username, default_tablespace from dba_users;

1. view the table structure: DESC table name

2. view the table of the current user:

1. SelectTable_name
   FromUser_tables;
   

3. view the table names of all users:

1. SelectTable_name
   FromAll_tables;
   

4. View All table names (including system tables)

1. SelectTable_name
   FromAll_tables;
   

5. View All Tables:

1. Select*
   FromTab/dba_tables/dba_objects/CAT;
   

The following describes how to query user tablespaces in Oracle.

◆ Oracle query user tablespace: Select * From user_all_tables

◆ Oracle queries all functions and stored procedures: Select * From user_source

◆ Query all oracle users: Select * From all_users.select * From dba_users

◆ Oracle view current user connection: Select * from V $ session

◆ View current user permissions in Oracle: Select * From session_privs

◆ ORACLE:

1. Select a. file_id "fileno", A. tablespace_name

1. "Tablespace_name ",

1. A. bytes "bytes", A. bytes-sum (nvl (B. bytes, 0) "used ",

1. Sum (nvl (B. bytes, 0) "free ",

1. Sum (nvl (B. bytes, 0)/A. bytes * 100 "% free"

1. From dba_data_files A, dba_free_space B

1. Where a. file_id
   = B
   . File_id (+)

1. Group by A. tablespace_name,

1. A. file_id, A. bytes order by A. tablespace_name;

1. view All users: Select * From dba_user; select * From all_users; select * From user_users; 2. view user system permissions: Select * From dba_sys_privs; select * From all_sys_privs; select * From user_sys_privs; 3. view user object permissions: Select * From dba_tab_privs; select * From all_tab_privs; select * From user_tab_privs; 4. view All roles: Select * From dba_roles; 5. view User Roles: Select * From dba_role_privs; select * From user_role_privs;

6. view the permissions of a role:

  select * from role_sys_privs;

  select * from role_tab_privs;

7. View All system Permissions

  select * from system_privilege_map; 

8. View All object permissions

  select * from table_privilege_map;

The preceding command is used to view User Permissions in Oracle. in DB2, select * From syscat. dbauth or get authorizations is used.

View Sid select * from V $ instance