OCP-1Z0-053-V13.02-512题

512.Which two statements correctly describe the relationship among the Scheduler components: job,

program, and schedule? (Choose two)

A. A job is specified as part of a program definition

B. A program can be used in the definition of multiple jobs

C. A program and job can be specified as part of a schedule definition

D. A program and schedule can be specified as part of a job definition

Answer: A

答案解析：

参考：http://docs.oracle.com/cd/E11882_01/server.112/e25494/schedover.htm#ADMIN12374

http://docs.oracle.com/cd/E11882_01/server.112/e25494/schedover.htm#ADMIN12357

正确答案BD

Programs

A program object (program) describes what is to be run by the Scheduler. A program includes:

• An action: For example, the name of a stored procedure, the name of an executable found in the operating system file system (an "external executable"), or the text of a PL/SQL anonymous block.

• A type: STORED_PROCEDURE, PLSQL_BLOCK, or EXTERNAL, where EXTERNAL indicates an external executable.

• Number of arguments: The number of arguments that the stored procedure or external executable accepts.

A program is a separate entity from a job. A job runs at a certain time or because a certain event occurred, and invokes a certain program. You can create jobs that point to existing program objects, which means that different jobs can use the same program and run the program at different times and with different settings. With the right privileges, different users can use the same program without having to redefine it. Therefore, you can create program libraries, where users can select from a list of existing programs.

If a stored procedure or external executable referenced by the program accepts arguments, you define these arguments in a separate step after creating the program. You can optionally define a default value for each argument.

调度程序使用以下基本组件：

• “作业”指定要执行的操作。它可以是PL/SQL 过程、纯二进制可执行文件、Java 应用程序或Shell 脚本。可以将程序（内容）和调度（时间）指定为作业定义的一部分，

也可以改用现有的程序或调度。可以使用作业的参数来定制其运行时行为。

• “调度”指定作业的执行时间和次数。调度可以基于时间或事件。可以为作业定义调度，方法是使用一系列日期、一个事件，或两者相结合，以及表示重复间隔的附加说

明。可以单独存储作业的调度，然后对多个作业使用同一个调度。

• “程序”是有关特定可执行文件、脚本或过程的元数据集合。自动作业将执行某个任务。使用程序，无需修改作业本身即可修改作业任务或者“内容”。可以定义程序的参数，使用户可以修改任务的运行时行为。

How Programs, Jobs, and Schedules are Related

To define what is executed and when, you assign relationships among programs, jobs, and schedules. Figure 28-5 illustrates examples of such relationships.

Figure 28-5 Relationships Among Programs, Jobs, and Schedules

Description of "Figure 28-5 Relationships Among Programs, Jobs, and Schedules"

To understand Figure 28-5, consider a situation where tables are being analyzed. In this example, program P1 analyzes a table using the DBMS_STATS package. The program has an input parameter for the table name. Two jobs, J1 and J2, both point to the same program, but each supplies a different table name. Additionally, schedule S1 specifies a run time of 2:00 a.m. every day. The end result is that the two tables named in J1 and J2 are analyzed daily at 2:00 a.m.

Note that J4 points to no other entity, so it is self-contained with all relevant information defined in the job itself. P2, P9 and S2 illustrate that you can leave a program or schedule unassigned if you want. You can, for example, create a program that calculates a year-end inventory and temporarily leave it unassigned to any job.