OCA/OCP Oracle Database 11g All-in-One Exam Guide 66 of the directory into which the file was unzipped, viewed from a command window. Note the presence of the readme.html file. This contains the product release notes—open it in a browser, and read them. 3. Confirm success of your installation by running the sqldeveloper.exe executable file, either from the command prompt or by double-clicking it in Windows Explorer. Oracle Enterprise Manager The version of Oracle Enterprise Manager relevant to the OCP examination is Database Control. This is a tool for managing one database (which can be a RAC database), whereas Grid Control can manage many databases (and more). Database Control is installed into the Oracle Home. It consists of a Java process that monitors a port for incoming connection requests. If there are several database instances running off the same Oracle Home, each instance will be accessible through Database Control on a different port. Database Control connects to the database on behalf of the user. It has built-in monitoring capability and will display real-time information regarding alert conditions, activity, and resource usage. It also gives access to many wizards that can make database management and tuning tasks feasible for novice DBAs, and quick to carry out for experienced DBAs. Starting and stopping the Database Control process is described in Chapter 3; using it for management tasks is demonstrated in most subsequent chapters. TIP Oracle Enterprise Manager can be a very useful tool, but never use it without understanding what it is doing. Many DBAs like to work from the SQL*Plus or SQL Developer command line to understand exactly how to do something, and then use Enterprise Manager to make doing it easy. It is also a nice tool for checking syntax for a command you’ve forgotten. Chapter 2: Installing and Creating a Database 67 PART I Other Administration Tools There are a number of other utilities that will be used in the course of this book. In many cases, there are both graphical and command-line interfaces. All of these are installed into the Oracle Home. Oracle Net Manager, Oracle Net Configuration Assistant These are two Java graphical tools for configuring the Oracle networking environment. There is considerable overlap in their functionality, but each does have some capability lacking in the other. Most network administration tasks can also be done through Database Control, and all can be done by editing configuration files by hand. Historically, manual editing of the Oracle Net configuration files could be an extremely dodgy business: many DBAs believed that the files were very sensitive to trifling variations in format such as use of white spaces, abbreviations, and case. For this reason alone, the graphical tools have always been popular. Recent releases of Oracle Net appear to be less sensitive to such issues, but the graphical tools are still useful for preventing silly syntax errors. Data Loading and Unloading Utilities The classical utilities for transferring data between Oracle databases are the Export and Import tools. Export runs queries against a database to extract object definitions and data, and writes them out to an operating system file as a set of DDL and DML commands. Import reads the file and executes the DDL and DML statements to create the objects and enter the data into them. These utilities were very useful for transferring data between databases, because the transfer could go across operating systems and Oracle versions, but because they work through regular user sessions (they are client-server tools), they were not always suitable for large-scale operations. Export files can only be read by Import. The replacement for Export and Import is Data Pump, introduced with release 10g. Functionally, Data Pump is very similar: it extracts data from one database, writes it out to a file, and inserts it into another database (possibly a different version, on a different platform). But the implementation is completely different. Data Pump uses background processes, not server sessions, to read and write data. This makes it much faster. Launching, controlling, and monitoring Data Pump jobs is done through client-server sessions, but the job itself all happens within the instance. Export and Import are still supported, but Data Pump is the preferred utility. Data Pump–generated files can only be read by Data Pump: there is no compatibility with Export and Import. SQL*Loader is a tool for loading large amounts of data into an Oracle database from operating system files. These files can be laid out in a number of formats. There are restrictions on the formats SQL*Loader can use, but it is a pretty versatile tool and can be configured to parse many file layouts. Typical usage is the regular upload of data into an Oracle database from a third-party feeder system: the third-party database will write the data out in an agreed format, and SQL*Loader will then load it. EXAM TIP Data Pump can read only files generated by Data Pump, but SQL*Loader can read files generated by any third-party product, so long as the file is formatted in a way that can be parsed. OCA/OCP Oracle Database 11g All-in-One Exam Guide 68 Data Pump and SQL*Loader are described in Chapter 23. Both utilities have command-line interfaces and a graphical interface through Database Control. TIP Export and Import will be useful for a long time to come. Data Pump is available only for releases 10g and 11g, so whenever it is necessary to transfer data to or from 9i and earlier databases, the older utilities will still be needed. It is well worth getting familiar with them. Backup Utilities It is possible to back up an Oracle database using operating system utilities. Operating system backups (known as user-managed backups) are fully supported, and there are circumstances when they may be the best option. But the preferred tool is RMAN, the Recovery Manager. RMAN backups are known as server-managed backups. RMAN is introduced and used for simple backup and restore operations in Chapters 15–17. RMAN server-managed backups have capabilities that user-managed backups cannot provide. These include incremental backups, where only the changed blocks of a datafile are backed up; block-level restore and recovery, where if the damage to a file is only to a small part of the file, just that part can be repaired; the application of an incremental backup to full backup, to roll it forward; and validating the datafiles to detect corruptions before end users hit them. TIP The degree of knowledge of backup and recovery techniques tested by the OCP examinations may not be adequate for a DBA to be considered fully competent. Remember that the OCP curriculum is only an introduction to database administration. Backup is a critical task and will require further study. The Oracle Secure Backup facility lets the DBA manage backup of the entire environment: Oracle Application Servers, remote clients, and operating system files, as well as the database. It is developed by Oracle in conjunction with operating system and hardware vendors. Plan an Oracle Database Installation Before running OUI, it is necessary to confirm adequate hardware and operating system resources, to make a decision about where to install the software, and to consider setting some environment variables. Choice of Operating System Some people become almost religiously attached to their favorite operating system. Try to avoid this. All operating systems have good and bad points: none are suitable for all applications. In general, Oracle Corporation supports all the mainstream platforms, including • Linux on Intel and AMD Chapter 2: Installing and Creating a Database 69 PART I • Microsoft Windows on Intel and AMD • Solaris on SPARC • AIX on POWER • HPUX on PA-RISC These platforms are probably the most common, but there are many others. Some operating systems are available in both 32-bit and 64-bit versions to support different popular machine architectures. Usually, Oracle ports the database to both. When selecting an operating system, the choice should be informed by many factors, including • Cost • Ease of use • Choice of hardware • Available skills • Scalability • Fault tolerance • Performance There are other factors, and not only technical ones. Corporate standards will be particularly important. Linux deserves a special mention. Oracle Corporation has made a huge commitment to Linux, and Linux is used as the development platform for many products (including database release 11g). Linux comes in several distributions. The most popular for Oracle servers are Red Hat and SUSE, but do not ignore the Oracle distribution: Enterprise Linux. This is very well packaged and fully supported by Oracle Corporation. This means you can have one support line for the entire server technology stack. Hardware and Operating System Resources Determining the necessary hardware resources for an Oracle database server requires knowledge of the anticipated data volumes and transaction workload. There are sizing guides available on MetaLink. The minimum hardware requirements for a usable system are • 1GB RAM • 1.5GB swap space • 400MB in the TEMP location • 1.5GB–3.5GB for the Oracle Home • 1.5GB for the demonstration seed database • 2.4GB for the flash recovery area • A single 1GHz CPU OCA/OCP Oracle Database 11g All-in-One Exam Guide 70 The wide range in space for the Oracle Home is because of platform variations. Around 2.5GB is typical for the Windows NTFS file system, 3.5GB for the Linux ext3 file system. The flash recovery area is optional. Even if defined, there is no check made as to whether the space is actually available. Machines of a lower specification than that just given can be used for learning or development but would not be suitable for anything else. The TEMP location is a directory specified by the TEMP environment variable. The server operating system must be checked for compliance with the Oracle certified platforms, bearing in mind these issues: • That some operating systems come in 32-bit and 64-bit versions • Correct version and patch level • Required packages • Kernel parameters These prerequisite factors will be checked by the OUI. Exercise 2-2: Confirm Available Hardware Resources In this exercise, you will check what resources are available, first for Windows and second for Linux. Windows: 1. Right-click My Computer, and bring up the Properties dialog box. Note the amount of RAM. This should be at least 512MB, preferable 1GB. 2. Choose the Advanced tab, and then in the Performance section click the SETTINGS button. 3. In the Performance Options dialog box select the Advanced tab. Note the virtual memory setting. This should be at least one and a half times the memory reported in Step 1. 4. Open a command window, and find the location of your temporary data directory with this command: C:\> echo %TEMP% This will return something like C:\ Temp Check that there is at least 400MB free space on the file system returned (in this example, it is drive C:). 5. Identify a file system with 5GB free space for the Oracle Home and a database. This must be a local disk, not on a file server. If you want to stage the installation media (you probably do), that will need another 1.5GB, which can be on a file server. Linux: 1. From an operating system prompt, run free to show main memory and swap space, which should ideally both be at least 1GB. These are the values in the total column. In the illustration that follows, they are both about 2GB. Chapter 2: Installing and Creating a Database 71 PART I 2. Run df -h to show the free space in each mounted file system. Confirm that there is a file system with 5GB free for the Oracle Home and the database. Confirm that there is 400MB free in /tmp if it exists as a separate file system; if there is no specific file system for /tmp (as is the case in the illustration), you can assume that it is in the root file system. In the illustration, there is 23GB free in the root file system. 3. Use rpm to check that all required packages are installed, at the correct (or later) version. In the illustration, the sysstat package is being checked. 4. Use sysctl to check that all the required kernel settings have been made— you may need to have root privilege to do this. In the illustration, the IP port range is being checked. Optimal Flexible Architecture The Oracle Home will need a file system into which it can be installed. Oracle Corporation has designed OFA, the Optimal Flexible Architecture, as a file system directory structure that should make maintaining multiple versions of multiple Oracle products straightforward. The heart of OFA is two environment variables: ORACLE_ BASE and ORACLE_HOME. The ORACLE_BASE directory is one directory on the server, beneath which all the Oracle software (all products, all versions) should be installed. Each version of each product will then have its own ORACLE_HOME, beneath the ORACLE_BASE. This structure should ensure that many databases can be created and upgraded without ever ending up with files in inappropriate locations. The Linux and Unix OFA standard for ORACLE_BASE is that it should be a directory named according the template /pm/h/u, where p is a string constant such as u, m is a numeric constant such as 01, h is a standard directory name such as app, and u is the operating system account that will own all the Oracle software, such as oracle. The Windows OFA standard for ORACLE_BASE is \oracle\app off the root of any suitable drive letter. OCA/OCP Oracle Database 11g All-in-One Exam Guide 72 The OFA standard for the database ORACLE_HOME is $ORACLE_BASE/product/v/ db_n, where product is the constant product, v is the release number of the product such as 11.1.0, and db_n is a name derived by the installer based on which product it is, such as db for database, and an incrementing number for each installation of that product, such as 1. Typical Linux values for ORACLE_BASE and ORACLE_HOME are /u01/app/oracle /u01/app/oracle/product/11.1.0/db_1 and typical Windows values are D:\oracle\app D:\oracle\app\product\11.1.0\db_1 The OFA location for the database itself is ORACLE_BASE/q/d, where q is the string oradata and d is the name of the database. A Linux example for a database called orcl is /u01/app/oracle/oradata/orcl Within the database directory, the controlfile copies, online redo logfiles, and datafiles should be named as follows: File Type Name Variable Examples Controlfile controlnn.ctl nn is a unique number control01.ctl, control02.ctl Redo logfiles redonn.log nn is the online redo logfile group number redo01.log, redo02.log Datafiles tablespacenamenn.dbf the datafile’s tablespace name and a number system01.dbf, system02.dbf TIP OFA does not specify the naming convention for multiplexed online redo logfiles. Many DBAs suffix the OFA name with a letter to differentiate members in the same group: redo01a.log, redo01b.log. Environment Variables One significant difference between Windows and Unix operating systems is in the way in which environment variables are set. Within the Unix family, there are further variations depending on the shell being used. On Windows operating systems, there is the registry: Unix has no equivalent of this. The Oracle database makes use of several environment variables, some of which can be set before even running the OUI. The OUI will prompt for them, using the preset values as defaults. On Linux, the one variable that must be set before the installer can run is DISPLAY. Chapter 2: Installing and Creating a Database 73 PART I Variables in Windows Variables can be set at various levels with various degrees of persistence on a Windows system, ranging from permanent, system-wide variables set in the Windows registry to variables set interactively within a command shell. As a general rule, variables set at a higher level (such as within the registry) can be overruled at a lower level (such as within a shell). The highest level for variables is in the registry. The OUI creates a key in the registry, HKEY_LOCAL_MACHINE\SOFTWARE\ORACLE and defines variables for each installed Oracle product beneath this. Figure 2-2 earlier shows the variables set for the ORACLE key, and then those set one level down, in the key KEY_OraDb11g_home1. At the ORACLE level, the variable inst_loc defines the location of the OUI inventory, described previously. Beneath this level there are keys for each installed product. In the example shown, there are two products installed: JInitiator (which is Oracle’s client-side JVM for running the Forms viewing applet—two versions have been installed on the system) and Database 11g. In the key KEY_OraDb11g_home1 there are a number of variables, two of the more significant being the ORACLE_BASE and the ORACLE_HOME. Others specify the locations of various components and the options Windows should use for automatic startup and shutdown of a database instance called ORCL. TIP There is no easy way to query the value of a Windows registry variable, other than by looking at the registry with a tool such as the regedit.exe registry editing tool. For this reason, many DBAs like to set variables at the session level, from where they can be easily retrieved and used. Figure 2-4 shows an example of doing this. Figure 2-4 Setting and using Windows environment variables OCA/OCP Oracle Database 11g All-in-One Exam Guide 74 The commands for setting up the environment in the manner desired would usually be specified in a batch file that could be invoked from the command line or as a login script. Variables in Linux The syntax for setting and reading environment variables varies from one shell to another. The examples that follow are for the bash shell, because that is possibly the most widely used Linux shell. Linux environment variables are always session specific. They must all be set up for each session—there is no equivalent of the Windows registry setting up variables with a scope that can include all sessions. To simulate setting what might be thought of as “global” variables applying to all sessions by all users, set them in the /etc/ profile file, which is executed at each logon. Figure 2-5 shows examples of setting and using bash shell environment variables. Note that in Figure 2-5 two more variables are being set on Linux than in Figure 2-4 on Windows. The LD_LIBRARY_PATH variable should include all dynamically linked libraries that may be needed, and the DISPLAY must be set to point to the terminal on which the user is working. EXAM WATCH If the DISPLAY variable is not set appropriately, OUI will not be able to open any windows and will throw an error. Install the Oracle Software by Using the Oracle Universal Installer (OUI) To run the OUI for the first time, log on to the server machine as an operating system user with permission to read the installation media (or the directory to which it has been staged) and to write to the directory chosen for the ORACLE_BASE. Then launch the OUI by running setup.exe (Windows) runInstaller.sh (Linux) Figure 2-5 Setting and using environment variables in the bash shell Chapter 2: Installing and Creating a Database 75 PART I To bypass the prerequisite checks (not advised, but may be useful), add a switch: runinstaller -ignoreSysPrereqs It is possible to do an unmanaged installation known as a silent install. This will be necessary if there is no graphics device, and is very convenient if you are performing many identical installs on identical machines. Also, it becomes possible to embed an Oracle installation within the routine for deploying a packaged application. A silent install requires a response file, which includes answers to all the prompts that would usually be manually given. The syntax for running the OUI in this way is runInstaller -silent -responsefile responsefilename The response file can be created manually (there are examples in the /response directory on the installation media), or it can be recorded by OUI during an interactive install: runInstaller -record -destinationFile responsefilename Before doing a silent install, the inventory pointer file (/etc/oraInst.loc on Linux) must have been created, or OUI will not be able to locate (or create if necessary) the inventory. Exercise 2-3: Install the Oracle Home In this exercise, install an Oracle Home on Linux using the OUI. 1. Log on to Linux as a user who is a member of the dba group. In the following example, the operating system user is db11g. Confirm the username and group membership with the id command, as in this illustration: 2. Switch to the root user with su and create an OFA-compliant directory for the Oracle Base with the mkdir command. In the example, this is /u02/app/ db11g. Change the ownership and access modes of the directory such that the db11g user has full control of it with the chown and chmod commands, as in the preceding illustration, and exit back to the Oracle user. . database itself is ORACLE_ BASE/q/d, where q is the string oradata and d is the name of the database. A Linux example for a database called orcl is /u01/app /oracle/ oradata/orcl Within the database. account that will own all the Oracle software, such as oracle. The Windows OFA standard for ORACLE_ BASE is oracle app off the root of any suitable drive letter. OCA/ OCP Oracle Database 11g All-in-One. Explorer. Oracle Enterprise Manager The version of Oracle Enterprise Manager relevant to the OCP examination is Database Control. This is a tool for managing one database (which can be a RAC database) ,