ORACLE self-study notes

ORACLE self-study note: in Oracle, the three default users sys change_on_install [as sysdba] system managerscott tiger data dictionary can be used to view the system permissions of the current user. select * from user_sys_privs; select * from user_tab_privs; create user wangwu identified by wangwu; grant create session to wangwu; grant create table to wangwu; grant unlimited tablespace to wangwu; revoke permissions ...... revoke unlimited tablespace from wangwu; grant the create session to all users Public; grant create any table to public; object permission grant select on mytab to lisi; grant all on mytab to lisi ;... revoke all on mytab from lisi; set the display width: set linesize 400 to control the permission on the table column, for example: control lisi's permission to update the name column of the mytab table. grant update/insert (only these two columns are allowed. query and deletion cannot control the columns.) delete (name) on mytab to sili; query the columns that the current user has permissions on: select * from user_col_privs; permission transfer: grant alter any table to lisi with admin option; grant select on tableName Lisi with grant option; role: create role myrole; grant create session to myrole; drop role myrole; note that some system permissions cannot be directly granted to roles such as create any table, alter any table, drop any table. A table belongs to a user and a role does not belong to a user. Three authentication mechanisms for ORACLE databases: 1. operating system verification 2. password File verification 3. database verification the process of starting an ORACLE database in Linux: 1. lsnrctl start listener 2. sqlplus sys/oracle as sysdba 3. startup: user lock: alter user Username account lock user unlock: alter user Username account unlock user password expired: alter user Username password expire