Question

1. Study the Connecting to an XE Oracle Server document available by hyperlink from the course web site. Logon to your XE instance server account using windows/Linux/Unix command line. After logging on, answer following questions:

What is your home directory of ORACLE_HOME

What is your ORACLE_SID

What is you ORACLE_BASE directory?

2. Move to the ORACLE_HOME subdirectory. Examine the other subdirectories under ORACLE_HOME. Look in the dbs subdirectory that stores the PFILE for the XE database. The example PFILE is named init.ora. The init.ora file is a template that you can use to create your own PFILE. Locate the init.ora files

What is the database block size specified for the XE database with this init.ora file?

How many control files are defined and what are their names?

What version of Oracle is this database set to support for compatibility of features?

What is the name of the tablespace that supports UNDO management?

3. The XE database consists of multiple datafiles and other files. Explore and find and List the location of the XE database files

Answer 1

1

a)The Oracle home directory (ORACLE_HOME) is the directory where you choose to install the software for a particular Oracle product. You must install different Oracle products or different releases of the same Oracle product in separate Oracle home directories. When you run Oracle Universal Installer, it prompts you to specify the path to this directory as well as a name that identifies it. The directory that you specify must be a subdirectory of the Oracle base directory. Oracle recommends that you specify a path similar to the following for the Oracle home directory

oracle_base/product/11.2.0/dbhome_1

Oracle Universal Installer creates the directory path that you specify under the Oracle base directory. It also sets the correct permissions on it. You do not need to create this directory.

b)

The SID is a site identifier. It plus the Oracle_home are hashed together in Unix to create a unique key name for attaching an SGA. If your Oracle_sid or Oracle_home is not set correctly, you'll get "oracle not available" since we cannot attach to a shared memory segment that is identified by magic key. On NT, we don't use shared memory but the SID is still important. We can have more then 1 database on the same oracle home so we need a way to id them.

Changing it harder then it looks. I know you are on unix, so here are the steps for changing it (or the database name) under Unix - they are different on NT.

c)

The Oracle base directory is a top-level directory for Oracle software installations.

2)

a) The most commonly used block size should be picked as the standard block size. In many cases, this is the only block size that you need to specify. Typically, DB_BLOCK_SIZE is set to either 4K or 8K. If you do not set a value for this parameter, the default data block size is operating system specific, which is generally adequate.

You cannot change the block size after database creation except by re-creating the database. If the database block size is different from the operating system block size, ensure that the database block size is a multiple of the operating system block size. For example, if your operating system block size is 2K (2048 bytes), the following setting for the DB_BLOCK_SIZE initialization parameter is valid:

DB_BLOCK_SIZE=4096

A larger data block size provides greater efficiency in disk and memory I/O (access and storage of data). Therefore, consider specifying a block size larger than your operating system block size if the following conditions exist:

Oracle Database is on a large computer system with a large amount of memory and fast disk drives. For example, databases controlled by mainframe computers with vast hardware resources typically use a data block size of 4K or greater.

The operating system that runs Oracle Database uses a small operating system block size. For example, if the operating system block size is 1K and the default data block size matches this, the database may be performing an excessive amount of disk I/O during normal operation. For best performance in this case, a database block should consist of multiple operating system blocks.

b)

Every Oracle Database has a control file, which is a small binary file that records the physical structure of the database. The control file includes:

The database name

Names and locations of associated datafiles and redo log files

The timestamp of the database creation

The current log sequence number

Checkpoint information

c)

When you upgrade to a new release of Oracle, certain new features may make your database incompatible with your previous release. Your upgraded Oracle database becomes incompatible with your previous release under the following conditions:

A new feature stores any data on disk (including data dictionary changes) that cannot be processed with your previous release.

An existing feature behaves differently in the new environment as compared to the old environment. This type of incompatibility is classified as a language incompatibility.

d)

Oracle Database supports automatic extension of the undo tablespace to facilitate capacity planning of the undo tablespace in the production environment. When the system is first running in the production environment, you may be unsure of the space requirements of the undo tablespace. In this case, you can enable automatic extension of the undo tablespace so that it automatically increases in size when more space is needed. You do so by including the AUTOEXTEND keyword when you create the undo tablespace.

3) Most users will install Oracle Database XE by downloading the installation executable, double-clicking it, and answering graphical user interface prompts as needed.

Before attempting to install Oracle Database XE 11.2 uninstall any existing Oracle Database XE or database with the SID XE from the target system.

If you have an existing version of Oracle Database XE, then save your data by exporting it to data files. After you install the new version of Oracle Database XE import this data into the new database. For more information see Section 7, "Importing and Exporting Data between 10.2 XE and 11.2 XE".

To perform a graphical user interface installation:

Log on to Windows with Administrative privileges.

You must be part of the Administrators group on Windows to install Oracle Database XE. If you are logged in as a domain user, ensure that you are connected to the network.

If the ORACLE_HOME environment variable has been set, then use System in the Control Panel to delete it.

Go to the following Web site:

http://www.oracle.com/technetwork/database/express-edition/downloads/index.htmlOpens a new window

Click Free Download and follow the instructions to select and download the Microsoft Windows version of Oracle Database XE.

After downloading the Oracle Database XE installation executable, setup.exe, double-click it.

"Oracle Database XE Character and Language Configurations" describes these character sets in detail.

In the Oracle Database 11g Express Edition - Install Wizard welcome window, click Next.

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In the License Agreement window, select I accept the terms in the license agreement and then click Next.

In the Choose Destination Location window, either accept the default or click Browse to select a different installation directory. (Do not select a directory that has spaces in its name.) Then click Next.

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