Oracle Management Data Dictionary (i) Oracle Common data Dictionary

1, the function of the data dictionary

The data dictionary records the system Information of the data, which is a collection of read-only tables and views.

The owner of the data dictionary is the SYS user, and it is saved in the system table space.

2, the concept of data dictionary

The data dictionary includes the data Dictionary base table and the data dictionary view two parts, in which, the base table stores the basic information of the database, the ordinary user cannot directly access the data dictionary base table; The Data dictionary view is a view based on the base table of the data dictionary, and ordinary users can obtain the system information by querying The data dictionary view mainly includes user_xxx, All_xxx, dba_xxx.

3. Common Data Dictionary

(1) DICT

Used to display all the data dictionary views that are accessible to the current user and give the purpose of these data dictionaries

04:23:22 sql> Select table_name,comments from Dict

04:23:41 2 where comments like '%grants% ';

TABLE_NAME COMMENTS

------------------------------ ----------------------------------------

User_col_privs_made all grants on columns of objects owned B

Y the user

User_tab_privs_made all grants on objects owned by the user

All_tab_privs_made user ' s grants and grants on user ' s OBJEC

Ts

(2) DUAL

Value used to return a function

04:26:39 sql> Select sysdate from dual;

Sysdate

-------------------

2011-02-19 04:26:41

04:26:41 sql> Select User from dual;

USER

------------------------------

SCOTT

04:26:47 sql> Select 4/2 from dual;

4/2

----------

2

(3) IND

Used to display all index and index statistics owned by the current user

04:31:45 sql> Col index_type for A10

04:31:52 sql> Col Uniqueness for A10

04:32:04 sql> Col index_name for A10

04:32:07 sql> Select Index_name,index_type,uniqueness

04:32:32 2 from Ind where table_name= ' EMP ';

Index_name Index_type Uniqueness

---------- ---------- ----------

Pk_emp NORMAL UNIQUE

04:32:49 sql> Select Index_name,index_type,uniqueness

04:32:56 2 from Ind where table_name= ' DEPT ';

Index_name Index_type Uniqueness

---------- ---------- ----------

Pk_dept NORMAL UNIQUE

(4) OBJ

Used to display all objects owned by the current user

04:35:51 sql> Select object_name, object_type,object_id, created from obj

04:36:08 2 ORDER by 2;

object_name object_type object_id CREATED

--------------- ------------------- ---------- -------------------

Pk_dept INDEX 51147 2005-06-30 19:47:57

Pk_emp INDEX 51149 2005-06-30 19:47:57

Get_emp_rec PROCEDURE 52534 2011-02-12 06:27:15

Salgrade TABLE 51151 2005-06-30 19:47:57

Quest_sl_temp_e TABLE 52515 2011-01-29 14:55:05

XPLAIN1

Logtable TABLE 52546 2011-02-12 07:47:29

EMP TABLE 51148 2005-06-30 19:47:57

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