OCA/OCP Oracle Database 11g All-in-One Exam Guide 56 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 Chapter 2: Installing and Creating a Database 57 PART I 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. OCA/OCP Oracle Database 11g All-in-One Exam Guide 58 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: <SYSTEM> <MEMORY> <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="2"/> <STEP NAME="PHYSICAL_MEMORY" GREATER_THAN="512" ATMOST="2048" UNIT="MB" MULTIPLE="1.5"/> <STEP NAME="PHYSICAL_MEMORY" GREATER_THAN="2048" ATMOST="8192" UNIT="MB" MULTIPLE="1"/> <STEP NAME="PHYSICAL_MEMORY" GREATER_THAN="8192" UNIT="MB" MULTIPLE="0.75"/> </SWAP_SIZE> </MEMORY> </SYSTEM> <CERTIFIED_SYSTEMS> <OPERATING_SYSTEM> <VERSION VALUE="5.0"/> <SERVICE_PACK VALUE="1"/> </OPERATING_SYSTEM> Chapter 2: Installing and Creating a Database 59 PART I <OPERATING_SYSTEM> <VERSION VALUE="5.1"/> <SERVICE_PACK VALUE="1"/> </OPERATING_SYSTEM> <OPERATING_SYSTEM> <VERSION VALUE="5.2"/> </OPERATING_SYSTEM> <! Microsoft Windows Vista > <OPERATING_SYSTEM> <VERSION VALUE="6.0"/> </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> <PACKAGE NAME="make" VERSION="3.81" /> <PACKAGE NAME="binutils" VERSION="2.17.50.0.6" /> <PACKAGE NAME="gcc" VERSION="4.1.1" /> <PACKAGE NAME="libaio" VERSION="0.3.106" /> <PACKAGE NAME="libaio-devel" VERSION="0.3.106" /> <PACKAGE NAME="libstdc++" VERSION="4.1.1" /> <PACKAGE NAME="elfutils-libelf-devel" VERSION="0.125" /> <PACKAGE NAME="sysstat" VERSION="7.0.0" /> <PACKAGE NAME="compat-libstdc++-33" VERSION="3.2.3" /> <PACKAGE NAME="libgcc" VERSION="4.1.1" /> <PACKAGE NAME="libstdc++-devel" VERSION="4.1.1" /> <PACKAGE NAME="unixODBC" VERSION="2.2.11" /> <PACKAGE NAME="unixODBC-devel" VERSION="2.2.11" /> </PACKAGES> <KERNEL> <PROPERTY NAME="semmsl" NAME2="semmsl2" VALUE="250" /> <PROPERTY NAME="semmns" VALUE="32000" /> <PROPERTY NAME="semopm" VALUE="100" /> <PROPERTY NAME="semmni" VALUE="128" /> <PROPERTY NAME="shmmax" VALUE="536870912" /> <PROPERTY NAME="shmmni" VALUE="4096" /> <PROPERTY NAME="shmall" VALUE="2097152" /> <PROPERTY NAME="file-max" VALUE="65536" /> <PROPERTY NAME="VERSION" VALUE="2.6.18" /> <PROPERTY NAME="ip_local_port_range" ATLEAST="1024" ATMOST="65000" /> <PROPERTY NAME="rmem_default" VALUE="4194304" /> <PROPERTY NAME="rmem_max" VALUE="4194304" /> <PROPERTY NAME="wmem_default" VALUE="262144" /> <PROPERTY NAME="wmem_max" VALUE="262144" /> </KERNEL> OCA/OCP Oracle Database 11g All-in-One Exam Guide 60 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. Chapter 2: Installing and Creating a Database 61 PART I 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. OCA/OCP Oracle Database 11g All-in-One Exam Guide 62 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 11 g 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 Chapter 2: Installing and Creating a Database 63 PART I 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 OCA/OCP Oracle Database 11g All-in-One Exam Guide 64 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 Chapter 2: Installing and Creating a Database 65 PART I 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 . OCA/ OCP Oracle Database 11g All-in-One Exam Guide 56 Perhaps the simplest yet most important strategic task in the life of an Oracle database occurs at the planning and installation phase. Although. 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,. 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.