OCP-052考試題庫彙總（42）-CUUG内部解答版

You successfully executed these commands:

connect scott/tiger@prod1;

CREATE DATABASE LINK db_prod2

CONNECT TO scott IDENTIFIED BY tiger

USING 'PROD2';

Which type of database link is created?

A)private current user database link

B)public connected user database link

C)public current user database link

D)private fixed user database link

E)public fixed user database link

Answer: D

趙：

總結：

預設建立的是 private connect，create 子句中沒有這兩個關鍵字，是 private connected 類型的;

Create 子句中有 public 關鍵字的是 public 類型的;

Create 子句中有 current_user 關鍵字的是 current 類型的;

Create 子句中有 identified by 關鍵字的是 fixed 類型的;

資料：blog-itpub-net/31397003/viewspace-2137245/

PDF 上有個表格沒複制過來。

CREATE SHARED database link link_name

CONNECT TO [user IDENTIFIED BY password]

[AUTHENTICATED BY user IDENTIFIED BY password]

[USING 'connect_string']

Dblink 分三類：使用者級(private)、資料庫級(public)、網絡級。

預設情況下建立的是使用者級(private)。

另參考：www-cnblogs-com/sumsen/archive/2013/03/04/2943471.html

幾種類型DBLINK建立示例：

--Private connected user

CREATE database link

sales.us.americas.acme_auto.com USING ‘sales_us’;

--Private current user

CREATE database link foo

CONNECT TO CURRENT_USER USING ‘am_sls’;

--Private fixed user

sales.us.americas.acme_auto.com

CONNECT TO scott IDENTIFIED BY tiger USING ‘sales_us’;

--Public fixed user

CREATE PUBLIC database link

sales CONNECT TO scott IDENTIFIED BY tiger USING ‘rev’;

--Shared public fixed user

CREATE SHARED PUBLIC database link

CONNECT TO scott IDENTIFIED BY tiger AUTHENTICATED BY

anupam IDENTIFIED BY bhide USING ‘sales’;