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Progress Check Image

1. What's better: ''shutdown transactional" or "shutdown immediate"?

2. Do you only need to worry about logical schema objects that do not take up a large amount of space?

3. What happens if your archive log directory becomes full?

4. Why would you want to use a command-line interface rather than a GUI to perform your tasks as a DBA?

CRITICAL SKILL 3.9
Manage Users

Before you can do anything in Oracle, you need to have a user ID created to enable you to log in to Oracle. As a DBA, you will begin with the SYS or SYSTEM accounts since these accounts both have the DBA role and exist in all Oracle databases. They are often used to perform database administration tasks. The SYS account is also granted the sysdba privilege and is the schema that the Oracle catalog is stored in. You should only use the SYS account when you need to perform a task as SYS or need the sysdba privilege. If your database was created using the Database Configuration Assistant (dbca), then you will also automatically get the SYSMAN and DBSNMP accounts. SYSMAN is used to administer Oracle Enterprise Manager (OEM) and DBSNMP is used by the agent that OEM employs to monitor Oracle databases. Several other accounts will also be set up for the "example" schemas, such as the Sales History ('SH') user that we will utilize throughout this book. The OUTLN schema will be created to allow you to use plan stability through the stored outline feature. Depending on the options you choose when creating your database, other accounts may be set up for you. For example, if you install the OLAP option, the OLAPSYS account will be created.

Progress Check Answers

1. Both leave your database in a consistent state. It depends on how long your transactions will take to complete or roll back. If all things are equal and you think that it will take as long to commit the transactions that are already running, then you should use "shutdown transactional" since commits will be allowed to complete and no data will be lost.

2. Logical schema objects need to be watched to ensure they are in a valid state.

3. If database attempts to write an archive log after the directory has become full, the database activity will be suspended until sufficient space is made available for the new file.

4. You may want to place the command in a script that is scheduled or run as a repetitive task.

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0131-CRITICAL SKILL 3.9 Manage Users