OCA /OCP Oracle Database 11g A ll-in-One Exam Guide- P11 pot

An Oracle Home is the location of an Oracle product installation: a set of files in a directory structure.. Before the Oracle Universal Installer, each product had its own self-containe

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Perhaps the simplest yet most important strategic task in the life of an Oracle database occurs at the planning and installation phase Although the decisions you make at this point are not cast in stone, they will often be complex to undo For example, choosing a database name, the locations of the installation binaries, and those of other important files might seem trivial, but once you have committed to these settings, they are usually permanent It is therefore well worth the effort to consider the key factors that influence planning, installing, and creating a database

This chapter begins by introducing the essential bread-and-butter tools used by Oracle DBAs and proceeds to discuss planning a database installation Once the plan

is made, installing the Oracle software is described and the chapter culminates with you creating your very own database

Identify the Tools for Administering

an Oracle Database

Oracle Corporation provides a number of tools for managing the Oracle environment First there is the Oracle Universal Installer (OUI) used (as its name suggests) to install any Oracle software Second is the Database Configuration Assistant (DBCA), the tool for creating a database A related tool used during upgrades is the Database Upgrade Assistance (DBUA), but a discussion of DBUA is beyond the scope of the exams These can be launched from the OUI or run separately Third, the OUI will install a number of other tools for managing a database and related components, notably SQL*Plus Depending

on the installation type chosen, it may also install SQL Developer

Oracle Enterprise Manager (OEM) Database Control is also installed by the OUI and will be used extensively in this book

The Oracle Universal Installer

Historically, managing Oracle software could be a painful task This was because the DBA was largely responsible for ensuring that incompatible products were kept separate It was not uncommon to install one product, a second, and a third satisfactorily—then installation

of a fourth would break the other three The problem of incompatibilities lies in the use

of the base libraries The base libraries provide facilities that are common to all Oracle

products For example, all Oracle products use the Oracle Net communications protocol;

it is impossible to install a product without it If two products are built on the same

version of the base libraries, then (theoretically) they can coexist in the same Oracle Home An

Oracle Home is the location of an Oracle product installation: a set of files in a directory structure Before the Oracle Universal Installer, each product had its own self-contained installation routine, which was sometimes not too clever at identifying incompatibilities with already installed products

The OUI is written in Java, using JDK/JRE1.5 This means that it is the same on all platforms The OUI can be installed as a self-contained product in its own Oracle Home, but this is not usually necessary, as it is shipped with every Oracle product and can be launched from the product installation media; it will install itself into the

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Oracle Home along with the product There are different versions of the OUI, and if

a product comes with an earlier version than one already installed on the machine,

then it will usually be a good idea (and may indeed be necessary) to install the

product using the already-installed version When the OUI prompts for the location

of a products.xml file, specify the media with the product you want to install

TIP Always use the latest version of the OUI that you have available There

can be issues with updating the OUI inventory if you try to revert to earlier

versions after using a later version

The OUI Inventory

Central to the OUI is the inventory This is a set of files that should ideally exist outside

any Oracle Home The inventory stores details of all the Oracle products installed on

the machine, including the exact version, the location, and in some cases details of

patches that have been applied Every run of the OUI will check the inventory for

incompatibilities before permitting an install into an existing Oracle Home to

proceed, and will then update the inventory with details of all products installed or

upgraded The location of the Unix inventory can be chosen by the DBA the first time

the OUI (any version) is run on the machine On Windows, the location is always

created in

%SystemRoot%\Program files\Oracle\Inventory

All platforms have a hard-coded, platform-specific location where the OUI will

search for an existing inventory pointer On Linux this is a file:

/etc/oraInst.loc

On Solaris it is also a file:

/var/opt/oracle/oraInst.loc

On Windows it is a key in the registry:

HKEY_LOCAL_MACHINE\SOFTWARE\ORACLE\inst_loc

When the OUI starts, it will look for this file (or registry key) If it does not exist,

OUI assumes that there has never been any Oracle software installed on the machine,

and it will create the file (or registry key) and write to it the location of the new

inventory that is to be created All subsequent runs of the OUI, no matter what

version, will then be able to find the inventory

This mechanism for creating an inventory pointer does raise an issue with

operating system privileges: on Linux or Unix, the user running the installer for the

first time will need permission to write to the appropriate directory Usually only the

root user can write to /etc or /var As it is not acceptable for security reasons to run

the OUI as the root user, OUI will generate a script (the orainstRoot.sh script) to

be run by the root user that will create the oraInst.loc file On Windows, the user

running the OUI will need privileges to create the registry key

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TIP To relocate the inventory, first copy it (the whole directory system to

which the inventory pointer is pointing) to the new location, and then edit the pointer file (or registry key) Sometimes, you may want to create a new inventory but keep the old one On Linux, simply delete the oraInst.loc file, run the OUI, and choose a location for the new inventory From then on, edit oraInst.loc to switch between the two inventories

The Prerequisite Tests

The OUI checks certain requirements on the server machine before it will run These are platform specific and are provided in this file on the installation media:

• /install/oraparam.ini (Unix)

• \install\oraparam.ini (Windows)

The requirements are not too demanding, doing little more than checking that the graphics device on which the installer is displaying can show at least 256 colors The oraparam.ini file also specifies the location of the file products.xml, which is the file with details of all the products that can be installed from this media Each product will have its own requirements, and these may be demanding (or irritating, if you know they actually don’t matter) The product requirements are listed

in a set of XML files Typical of these is

• /stage/prereq/db/refhost.xml (Unix)

• \stage\prereq\db\refhost.xml (Windows)

The Windows file is usually very simple, specifying little more than a calculation for necessary swap space, and the operating system release:

<PHYSICAL_MEMORY VALUE="256" UNIT="MB"/>

<! AVAILABLE_MEMORY VALUE="512" UNIT="MB"/ >

<SWAP_SIZE>

<STEP NAME="PHYSICAL_MEMORY" ATLEAST="0" ATMOST="256"

UNIT="MB" MULTIPLE="3"/>

<STEP NAME="PHYSICAL_MEMORY" GREATER_THAN="256" ATMOST="512"

UNIT="MB" MULTIPLE="1.5"/>

<STEP NAME="PHYSICAL_MEMORY" GREATER_THAN="8192"

UNIT="MB" MULTIPLE="0.75"/>

</SWAP_SIZE>

</MEMORY>

</SYSTEM>

<CERTIFIED_SYSTEMS>

<OPERATING_SYSTEM>

<SERVICE_PACK VALUE="1"/>

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<OPERATING_SYSTEM>

<SERVICE_PACK VALUE="1"/>

</OPERATING_SYSTEM>

<OPERATING_SYSTEM>

</OPERATING_SYSTEM>

<! Microsoft Windows Vista >

<OPERATING_SYSTEM>

</OPERATING_SYSTEM>

</CERTIFIED_SYSTEMS>

It is worth noting the swap space calculation, which is based on the amount of main

memory detected For instance, if OUI detects physical memory of 512MB–2048MB, it

will demand a swap file of 1.5 times the amount of physical memory OUI is not

intelligent enough to realize that Windows can resize its swap file, so that even if the

present size is far less than this, it could expand to far more Also note that the Windows

Vista base version (Windows version 6.0) is listed, but not with any service packs

The Unix prerequisites are more demanding, in that as well as a calculation for

required swap space they specify a whole list of packages and kernel settings, with

several sections for the various supported Unix versions Following is a print of a

typical section:

</PACKAGES>

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Obtaining the required packages can be a quite challenging for some Unix

distributions Also, some of the kernel settings (such as the ip_local_port_range) may conflict with local system administration policies If you cannot get your system into a state where it will pass the prerequisite tests, you have three options First, you can edit the oraparam.ini file or the refhost.xml file to change the value or to remove the test entirely This will “fix” the problem permanently Second, you can run the OUI with a switch that tells it to ignore the prerequisite tests Third, you can run the OUI and during the run tell it to ignore any failures This last option can only work when running OUI interactively, not when doing a silent install

If at all possible, do not do any of these! In practice, often the problem is not that the products will not work For example, on Linux, some of the kernel settings and packages are not really needed for an entry-level installation The problem, however, lies with the supportability of your installation If you ever raise an SR (an SR is a Service Request, passed to Oracle Support Services through MetaLink) and your system does not conform to the prerequisites, the support analysts may well refuse to help you So if you have to break one of the rules to get an installation through, fix it

as soon as possible afterward

Running the OUI

Oracle products are shipped on CDs or DVDs, or can be downloaded from Oracle Corporation’s web site The installation can be done directly from the CD or DVD, but it is usually better to copy the CD or DVD to disk first (this is called staging), and install from there This does save time, since you aren’t prompted to insert different media during the installation The downloaded versions are usually ZIP files, or for Linux and Unix compressed TAR or CPIO files Use whatever operating system utility

is appropriate to expand them

To launch the OUI, on Windows run the setup.exe file in the root directory, on Linux and Unix, run the runInstaller shell script

Database Creation and Upgrade Tools

The Database Configuration Assistant (DBCA) is a graphical tool used for creating and modifying a database Creating a database is not a big deal using DBCA The wizard-driven approach guides you through the database creations options, allowing you to determine parameter values and file location options DBCA then generates the appropriate scripts to create a database with the options you have chosen DBCA ensures there are no syntax errors and proceeds to run these scripts Everything that DBCA does can also be done manually using a command-line utility DBCA is

commonly launched by OUI When you opt for this, OUI instantiates the Oracle Home and then goes on to run DBCA

As with database creation, database upgrade can be done manually or through a graphical tool The graphical tool is the Database Upgrade Assistant (DBUA) It, too, can be called by OUI, if OUI detects an existing database Oracle Home of an earlier version The DBUA will ensure that no steps are missed, but many DBAs prefer to do upgrades manually They believe that it gives them more control, and in some cases a manual upgrade can be quicker

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Both DBCA and DBUA are written in Java and therefore require a graphics

terminal to display

Tools for Issuing Ad Hoc SQL: SQL*Plus

and SQL Developer

There are numerous tools that can be used to connect to an Oracle database Two

of the most basic are SQL*Plus and SQL Developer These are provided by Oracle

Corporation and are perfectly adequate for much of the work that a database

administrator needs to do The choice between them is partly a matter of personal

preference, partly to do with the environment, and partly to do with functionality

SQL Developer undoubtedly offers far more function than SQL*Plus, but it is more

demanding in that it needs a graphical terminal, whereas SQL*Plus can be used on

character-mode devices

SQL*Plus

SQL*Plus is available on all platforms to which the database has been ported, and it

is installed into both Oracle database and Oracle client Oracle Homes On Linux, the

executable file is sqlplus The location of this file will be installation specific but

will typically be something like

/u01/app/oracle/product/db_1/bin/sqlplus

Your Linux account should be set up appropriately to run SQL*Plus There are

some environment variables that will need to be set These are

• ORACLE_HOME

• PATH

• LD_LIBRARY_PATH

The PATH must include the bin directory in the Oracle Home The LD_LIBRARY_

PATH should include the lib directory in the Oracle Home, but in practice you may

get away without setting this Figure 2-1 shows a Linux terminal window and some

tests to see if the environment is correct

In Figure 2-1, first the echo command checks whether the three variables have

been set up correctly: there is an ORACLE_HOME, and the bin and lib directories

in it have been set as the first elements of the PATH and LD_LIBRARY_PATH variables

Then which confirms that the SQL*Plus executable file really is available, in the

PATH Finally, SQL*Plus is launched with a username, a password, and a connect

identifier passed to it on the command line

Following the logon, the next lines of text display the version of SQL*Plus being

used, which is 11.1.0.6.0, the version of the database to which the connection has

been made (which happens to be the same as the version of the SQL*Plus tool), and

which options have been installed within the database The last line is the prompt to

the user, SQL>, at which point they can enter any SQL*Plus or SQL command

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Historically, there were always two versions of SQL*Plus for Microsoft Windows: the character version and the graphical version The character version is the executable file sqlplus.exe, the graphical version was sqlplusw.exe; with the current release the graphical version no longer exists, but many DBAs will prefer to use it, and the versions shipped with earlier releases are perfectly good tools for working with an

11g database There are no problems with mixing client versions: an 11g SQL*Plus client can connect to a 9i database, and a 9i SQL*Plus client can connect to an 11g database; changes in Oracle Net may make it impossible to go back further than 9i

Following a default installation of either the Oracle database or just the Oracle client

on Windows, SQL*Plus will be available as a shortcut on the Windows Start menu The tests of the environment and the need to set the variables if they are not correct, previously described for a Linux installation, are not usually necessary on a Windows installation This is because the variables are set in the Windows registry by the Oracle Universal Installer when the software is installed If SQL*Plus does not launch successfully, check the registry variables Figure 2-2 shows the relevant section

of the registry, viewed with the Windows regedit.exe registry editor utility Within the registry editor, navigate to the key

HKEY_LOCAL_MACHINE\SOFTWARE\ORACLE\KEY_OraDb11g_home1

The final element of this navigation path will have a different name if there have

been several 11g installations on the machine.

SQL Developer

SQL Developer is a tool for connecting to an Oracle database (or, in fact, some non-Oracle databases too) and issuing ad hoc SQL commands It can also manage PL/SQL objects Unlike SQL*Plus, it is a graphical tool with wizards for commonly needed actions SQL Developer is written in Java, and requires a Java Runtime Environment (JRE) to run It is available on all platforms that support the appropriate version of the JRE SQL Developer does not need to be installed with the Oracle Universal

Figure 2-1

Checking the Linux

session setup

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Installer It is not installed in an Oracle Home but is completely self-contained The

latest version can be downloaded from Oracle Corporation’s web site

To install SQL Developer, unzip the ZIP file That’s all It does require at least JRE

release 1.5, to be available If a JRE is not available on the machine being used, there

are downloadable versions of SQL Developer for Windows that include it (These

versions include a Java Developers Kit or JDK which includes the JRE.) For platforms

other than Windows, JRE1.5 must be preinstalled Download it from Sun Microsystem’s

web site, and install it according to the platform-specific directions To check that the

JRE is available and its version, run the following command from an operating system

prompt:

java -version

This should return something like

java version 1.5.0_13

Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0_13-b05)

Java HotSpot(TM) Client VM (build 1.5.0_13-b05, mixed mode, sharing)

If the version number returned is not what you expect, using which java may help

identify the problem: the search path could be locating an incorrect version

Once SQL Developer has been unzipped, change your current directory to the

directory in which SQL Developer was unzipped, and launch it On Windows, the

executable file is sqldeveloper.exe On Linux, it is the sqldeveloper.sh shell

script Remember to check that the DISPLAY environment variable has been set to a

suitable value (such as 127.0.0.1:0.0, if SQL Developer is being run on the system

console) before running the shell script

Figure 2-2 The Oracle registry variable

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Any problems with installing the JRE and launching SQL Developer should be referred to your system administrator

TIP Database 11g does ship with a release of SQL Developer, and OUI

will unzip it into a directory in the Oracle Home, but this will not be the up-to-date version As of the time of writing, the version shipped with the

production release of the 11g database is version 1.1, but the current version

is 1.5

Figure 2-3 shows the SQL Developer User Interface after connecting to a database and issuing a simple query

The general layout of the SQL Developer window comprises a left pane for

navigation around objects, and a right pane to display and enter information

In the figure, the left-hand pane shows that a connection has been made to a database The connection is called orcl_sys This name is just a label chosen when the connection was defined, but most developers will use some sort of naming convention—in this case, the name chosen is the database identifier, which is orcl, and the name of the user the connection was made as, which was sys The branches beneath list all the possible object types that can be managed Expanding the branches would list the objects themselves The

Figure 2-3 The SQL Developer user interface

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right-hand pane has an upper part prompting the user to enter a SQL statement, and a

lower part that will display the result of the statement The layout of the panes and the

tabs visible on them are highly customizable

The menu buttons across the top menu bar give access to standard facilities:

• File A normal Windows-like file menu, from where one can save work and

exit from the tool

• Edit A normal Windows-like edit menu, from where one can undo, redo,

copy, paste, find, and so on

• View The options for customizing the SQL Developer user interface.

• Navigate Facilities for moving between panes, and also for moving around

code that is being edited

• Run Forces execution of the SQL statements, SQL script, or PL/SQL block

that is being worked on

• Debug Rather than running a whole block of code, step through it line by

line with breakpoints

• Source Options for use when writing SQL and PL/SQL code, such as

keyword completion and automatic indenting

• Migration Tools for converting applications designed for third-party databases

(Microsoft Access and SQL Server, and MySQL) to the Oracle environment

• Tools Links to external programs, including SQL*Plus.

• Help It’s pretty good.

SQL Developer can be a very useful tool, and it is very customizable Experiment

with it, read the Help, and set up the user interface the way that works best for you

Exercise 2-1: Install SQL Developer on Windows In this exercise, you will

install SQL Developer on a Windows machine

1 Download the current version of SQL Developer The URL is

http://www.oracle.com/technology/software/products/sql/index.html

Click the radio button to accept the license agreement, and then select the file

that includes the JDK (if you do not already have this) or without the JDK if it

already available on the machine

The file will be called something like sqldeveloper-1.2.1.3213.zip,

depending on the version

2 Move the file to an empty directory, and expand it You will need WinZip or

a similar utility installed to do this The next illustration shows the contents

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