OCP-052考試題庫彙總（46）-CUUG内部解答版

Examine this command:

SQL> CREATE GLOBAL TEMPORARY TABLE report_work_area

(startdate DATE,

enddate DATE,

class CHAR(20)) ON COMMIT PRESERVE ROWS;

Which three statements are true about rows inserted into REPORT_WORK_AREA?

A)Rows will be lost if a ROLLBACK is done.

B)Rows will be lost upon session failure.

C)Rows are visible to all sessions logged in by the same user until the session that inserted the rows terminates.

D)Rows are visible to all sessions logged in by all users granted the DBA role until the session that inserted the rows terminates.

E)Rows will be lost upon session normal termination.

F)Rows are visible globally to all sessions logged in by any user until the session that inserted the rows terminates.

Answer: ABE

趙：

on commit delete rows，事務送出時自動删除臨時表中的記錄。

on commit preserve rows，當使用者退出 session 時(會話結束後)自動清除臨時表的資料。

前者在事務送出後資料就已經清除了.後者在會話中止時或者正 s 常退出時資料都會被清除掉.

CDF 錯，Temporary Table 的資料存放在 PGA 或臨時表空間下，它被每個 session 單獨使用，即隔離session 間的資料，每個 session 隻能看到自己的資料。