SQL1-ch11 使用資料說明視觀表 (Data Dictionary) 管理物件

題號  80 題： 6 、 64  140 題： 105

視觀表命名規則

Q6/80 Which two statements are true? (Choose two.) A. The USER_SYNONYMS view can provide information about private synonyms. B. The user SYSTEM owns all the base tables and user- accessible views of the data dictionary. C. All the dynamic performance views prefixed with V$ are accessible to all the database users. D. The USER_OBJECTS view can provide information about the tables and views created by the user only. E. DICTIONARY is a view that contains the names of all the data dictionary views that the user can access.

user_objects 視觀表

user_tables 視觀表

user_constraints 視觀表

 CONSTRAINT_TYPE 的值包括：  C –check, P –primary key, U -unique  R –reference  DELETE_RULE 的值包括：  CASCADE ：刪除父項記錄時，子項記錄一起刪除。  NO ACTION ：只能刪除沒有子項記錄的父項記錄。  STATUS 的值包括：  ENABLED ：限制條件可使用。  DISABLED ：限制條件不可使用。

Q64/80 Evaluate the following SELECT statement and view the Exhibit to examine its output: SELECT constraint_name, constraint_type, search_condition, r_constraint_name, delete_rule, status FROM user_constraints WHERE table_name = ORDERS; Which two statements are true about the output? (Choose two.)

A. In the second column, indicates a check constraint. B. The STATUS column indicates whether the table is currently in use. C. The R_CONSTRAINT_NAME column gives the alternative name for the constraint. D. The column DELETE_RULE decides the state of the related rows in the child table when the corresponding row is deleted from the parent table.

Q105/140 Which statements are true? (Choose all that apply.) A. The data dictionary is created and maintained by the database administrator. B. The data dictionary views consist of joins of dictionary base tables and user-defined tables. C. The usernames of all the users including the database administrators are stored in the data dictionary. D. The USER_CONS_COLUMNS view should be queried to find the names of the columns to which a constraint applies. E. Both USER_OBJECTS and CAT views provide the same information about all the objects that are owned by the user. (P11-8) F. Views with the same name but different prefixes, such as DBA, ALL and USER, use the same base tables from the data dictionary