University:
Boston University
Course:
MET CS 201 | Introduction to Programming
Academic year:

2024
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12
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Hanusia3lug

Appendix A: Troubleshooting Common Installation and Usage Issues I forgot my password. If you forget your password, do not panic, because you can log in a different way and change your password. Your access to the computer onto which you installed Oracle means that you are able to login to Oracle as the SYS user without a password. Your privileges are akin to a master DBA in a production environment. See Appendix C for how to login as the SYS user without a password to reset your SYSTEM and user passwords. Because you typically install and use your own database locally in this course, security is not usually an issue for your student database. For class databases it is recommended to use an easily memorized password. Appendix B: Configuring Oracle Startup Options Your computer may become sluggish after installing Oracle. This can be normal when Oracle is running on a machine with limited resources. When Oracle first starts up it loads the database and performs other initialization. If you have adequate memory to support Oracle and the other programs that you are running on your computer the sluggishness will go away when Oracle has finished these startup operations. The sluggishness also goes away when Oracle is stopped. You will need to have the Oracle instance running only a fraction of the time, so you can stop Oracle when you aren’t using it. You can easily start and stop Oracle by starting and stopping the corresponding service. For an instance named SID, this service is called OracleServiceSID. Just right click on the service such as OracleServiceSID in the Services control panel and select Stop or Start. When the service is stopped it also stops the corresponding oracle.exe process, and when the service is started it also starts the process. To get to the Services control panel in Windows, first open the Control Panel. If you are on Windows XP, it's easier if you click the Switch to Classic View look. Then on XP you can launch the services control panel by going to Start then Settings then Control Panel then Administrative Tools then Services. In some cases, you may see a Services control right there in the control panel. If so, click on it and the services will come up. If you don't see Services, then you need to click on the Administrative Tools icon first. Then you will see Services and can click on that. Once the services control opens, you will see a list of services. Highlight the one that says OracleServiceSID, where SID is the name that you gave your Oracle service when you installed Oracle. The service name will be something like “OracleServiceORCL”. Then click Action/Stop. After a while the Oracle service shuts down the Oracle instance. Of course, once you stop it, Oracle is no longer running, so you'll have to repeat these steps and click "start" to start it again. Or, just rebooting your computer should make the service start again. Your computer will boot more slowly when Oracle is running, because the Oracle services are starting at boot time, and starting an Oracle instance can take a while, particularly on a notebook computer. You can configure Oracle so that it doesn’t start up when you boot your machine. Just open up the OracleServiceSID... service, as described above. But, instead of just clicking stop, you need to change the startup mode. Windows services have one of three startup modes ‐‐ automatic, manual, and disabled. By default, the Oracle service is in automatic mode. This means whenever you boot your computer, the service will start up automatically. You need to change it to manual to keep it from starting at boot time. To do so, right click on the OracleServiceSID... service then click the Properties option. From there, you should see the startup mode, and be able to switch it from automatic to manual. Do the same to the Oracle…TNSListener service. Then next time you boot, those services won't start. Of course, if you set these services to manual startup mode, then when you need to use Oracle, you'll need to go into the services again and start them manually. On recent Windows releases you can also reduce the time to boot while leaving Oracle running by hibernating your computer rather than shutting it down and rebooting it. Restarting after hibernation will take a little longer with Oracle running, but not nearly as long as rebooting with Oracle in automatic startup mode. Appendix C: How to reset your SYSTEM password on Windows This appendix provides instructions for resetting your Oracle SYSTEM password without reinstalling Oracle. This method uses the operating system authentication, which must be enabled for this to work. We will login to Oracle using the SYSDBA account for which operating system authentication is turned on by default for operating system users in the “dba” user group. Users with the administrator privilege on MSWindows are usually in the dba user group. This solution depends upon having SQLPlus or another comparable Oracle client installed on the machine. If you are running on a Microsoft Windows platform and you are logged onto the machine as a user in the "dba" operating system user group, which Oracle creates, you don't need to specify a password to connect as sysdba. Just go to the DOS (Command line) prompt and run "sqlplus / as sysdba". SQLPlus should be launched in the command line interface, connected to Oracle as SYSDBA. You can then change the SYSTEM password with the command: ALTER USER SYSTEM IDENTIFIED BY ; Where is replaced by the new password that you wish to give to the SYSTEM user. For a class installation choose something memorable, and write it down or store it on your computer. Production passwords should be carefully chosen to be resistant to attacks and the passwords should be carefully protected. After you have changed the SYSTEM password to something that you know, you can connect as SYSTEM, and do anything that you wish, including changing any passwords. There are similar ways of connecting to Oracle if you know the root password on UNIX family platforms. Appendix D: Additional Steps to Install Oracle on a Mac Oracle can be installed and used on a Mac, but this requires some setup work. There are many devoted Mac users today, yet the Mac platform is not supported by the major, modern DBMS vendors, including Oracle and SQL Server. If you find yourself in the situation where your home computer is a Mac, and you do not have a readily available Windows machine available for DBMS installation, you may need to install virtual machine software so that you can run Windows on your Mac. Using a Virtual Machine A virtual machine mostly behaves as any other application with some differences. The virtual machine has an application window that can be minimized and closed, the same as any other application. What makes a virtual machine different from an ordinary application is that an entire operating system is installed and executes inside of the virtual machine. The operating system running inside of the virtual machine, termed a “guest” operating system, runs as if it were to be on its own physical machine. This means we can install and use applications native to the guest operating system. Thus, once we are running a virtual machine, we are effectively running two operating systems at the same time – our machine’s operating system (termed the “host” operating system), and the guest operating system – and are using applications native to both operating systems at the same time. In our case, we are interested in running Windows as a guest operating system on our Mac. There are many virtual machines available for Macs; however, perhaps the two most popular are VirtualBox and Parallels. VirtualBox, available at http://virtualbox.org, is free to download and use. Parallels, available at http://parallels.com, costs money, but offers more features. Students have successfully used both to run both Windows and Oracle on a Mac in our BU program. Follow the steps below to install and use Oracle on your Mac: 1. Download and install your virtual machine of choice. 2. If you do not have a licensed copy of Windows, you will need to download one from the MSDNAA site. BU students are entitled to free, licensed copies of the latest versions of Windows through the MSDNAA site, and details on how to access this site are available in your course’s syllabus. 3. Install Windows inside of the virtual machine. 4. Proceed with the Oracle install instructions, starting from the beginning of this install guide, installing Oracle into the guest operating system. Note that Oracle offers a preconfigured VirtualBox image that comes with Oracle installed on Linux. The following URLs may be helpful to you to access this image: http://www.oracle.com/technetwork/community/developer‐vm/index.html http://www.oracle.com/technetwork/database/enterprise‐edition/databaseappdev‐vm‐ 161299.html Dual Booting Dual booting is another solution available to you if you have a modern Mac that runs on an Intel‐based processor. All new Macs run on Intel‐based processors, but older ones do not. Dual booting is a fairly simple concept. Normally when you power on your computer, your operating system starts booting immediately, and this happens seamlessly so that it appears your operating system is just a natural part of the computer. In actuality, when your computer is first powered on, it first loads a boot loader program, and that boot loader tells the operating system to start. If there is only one operating system, you may not even notice the work of the boot loader, because it always starts the same operating system. However, there is no reason why one cannot install two operating systems on their computer. In such a case, each time your computer is powered on, the boot loader asks you which operating system you would like to start, and also usually defaults to the first one if you do not select an option, after a timeout period. All new Macs come with what Apple terms “Boot Camp”, which is a built‐in utility that supports dual booting Mac OS X and Windows. To install Oracle in Windows on your Mac, you will need to: 1. Review the prerequisites needed to run Boot Camp and to install Windows as a second operating system on your Mac computer. The prerequisites are listed at http://support.apple.com/kb/HT1461. Ensure that your computer meets the requirements before continuing. 2. Obtain a licensed copy of Windows. If you do not have a licensed copy of Windows, you will need to download one from the MSDNAA site. BU students are entitled to free, licensed copies of the latest versions of Windows through the MSDNAA site, and details on how to access this site are available in your course’s syllabus. 3. Burn the copy of Windows onto a CD, or copy the ISO image onto a USB stick. Boot Camp supports installing Windows from either a CD or a USB stick. 4. Follow the steps recommended by Apple to install Windows using Boot Camp. Instructions are included with the utility, and you can also start here as well: http://support.apple.com/kb/HT1461 5. After Windows is installed, reboot your computer then boot into Windows. Proceed with the Oracle install instructions, starting from the beginning of this install guide. When you need to run Oracle, boot into Windows. When you need to use your Mac applications, boot into OS X. Using Virtual Machine Versus Dual Booting An obvious question is, which of these two options should you use? The answer depends upon your computer hardware, and your personal preferences. The following table summarizes the advantages and disadvantages of both options: Virtual Machine Advantages The guest operating system and its applications run at the same time as the host operating system and its applications. There is clipboard sharing between applications in both operating systems. Text can be copied from an application in one operating system, and pasted into an application in the second operating system. Dual Booting Because both operating systems run natively on the computer’s hardware, there is no performance overhead. Because both operating systems directly access the computer’s hardware, there are not hardware compatibility issues. The setup is conceptually simpler. Simply boot the operating system you need upon startup. Disadvantages Because the guest operating system is running under the control of virtual machine software, the guest operating system and its applications will execute noticeably slower than if they were running natively on the computer. Because both operating systems run concurrently, the performance of the host operating system may degrade. You can only run one operating system and its applications at a time. To start the second operating system, you must reboot. There is no clipboard sharing between applications in both operating systems. If text is to be shared across applications, it must be saved in a file then loaded by applications in the other operating system. If your hardware is powerful enough to support running two operating systems simultaneously, and still perform reasonably well, you may want to use a virtual machine, so that you can run both your Mac applications and your Windows applications at the same time. If you are concerned about obtaining the best performance for both operating systems, you may want to dual boot. A third advanced option, supported by the Parallels virtual machine, is to run the same Windows installation under a dual boot configuration and a virtual machine configuration. This is an advanced setup, and will require two Windows license registrations, as running the same installation both ways is the equivalent of running Windows on two different physical machines. Appendix E: Correcting Oracle Listener Issues If you attempt to establish a connection to your database, and the database client reports the following error, “Listener refused the connection with the following error: ORA‐12505”, this section may help you resolve the issue. The error looks similar to the following in Oracle SQL Developer: You may also see this issue while attempting an ODBC connection, as follows: There are two common causes for this error. The first cause is that one or more required Oracle services are not running. This cause is relatively simple to resolve, and should be resolved before attempting to resolve the second cause. The second cause is that the listener may be incorrectly configured. Correcting the second cause is a little more involved and requires updating configuration files. Cause 1: Oracle Services not started You will first want to verify that all required Oracle services are running. 1. Go to Start‐>Control Panel‐>Administrative Tools‐> Services 2. Scroll down to the services that begin with the word “Oracle”. Your screen should look something like this: Make sure that the following services have a status of “Started”: OracleOraDB11g_home1TNSListener OracleServiceXXXX, where XXXX is the Oracle SID you chose during the Oracle installation. If either or both of these services are not running, right click on them and select “Start” from the context menu. Starting the services may be all that you need to do in order to resolve the error. Cause 2: Incorrect Listener Configuration If you have verified that your required Oracle services are started, and you continue to see the “ORA‐12505” error, your listener may be incorrectly configured. The following steps may help you resolve the issue. 1. Update the tnsnames.org configuration file. a. Using Windows Explorer, go to this directory: C:\Oracle\product\11.2.0\dbhome_1\NETWORK\ADMIN Note that your directory may vary slightly, depending upon the version of Oracle you are installing, and upon the installation configuration. b. Open the tnsnames.ora file with a text editor, such as notepad or notepad++. When you first open the file, it will look similar to the following: First, completely delete the two lines associated with the LISTENER_XXXX construct. Next, change the word “SERVICE_NAME” to “SID”, and type in your SID after the equal sign. After the changes are applied, your file should look similar to the following: c. Now save the file with the changes. If Windows security will not let you save it as is, then save a copy to the desktop with the same name, then drag the file to the folder to replace the original. Windows will confirm this action with security dialog, which you should approve. 2. Update the listener.ora configuration file. a. Using Windows Explorer, go to this directory: C:\Oracle\product\11.2.0\dbhome_1\NETWORK\ADMIN Note that your directory may vary slightly, depending upon the version of Oracle you are installing, and upon the installation configuration. b. Open the listener.ora file with a text editor, such as notepad or notepad++. When you open the file, it will look similar to the following: c. If the machine name is not “localhost” and you are connecting locally to your machine, changing it to “localhost” may help resolve your connection issue. For example, if you see another name such as “HOST = My‐PC”, then you can change it to “Host = localhost” to help resolve your connection issue. d. The file has a missing line that you will add to the end of the file. At the end of the file, add the following line: SID_LIST_LISTENER = (SID_LIST = (SID_DESC = (ORACLE_HOME = C:\oracle\product\11.2.0\db\dbhome_1)(SID_NAME = LUMP))) Note that if your Oracle installation path differs from the above ORACLE_HOME path, you will need to enter the correct path for your installation. e. After updating the listener.ora file, it will look similar to the following: f. Now save the file with the changes. If Windows security will not let you save it as is, then save a copy to the desktop with the same name, then drag the file to the folder to replace the original. Windows will confirm this action with security dialog, which you should approve. 3. Restart the listener service. a. Go to Start‐>Control Panel‐>Administrative Tools‐>Services b. Scroll down to Oracle services. c. Right click on OracleOraDB11g_home1TNSListener and select “Restart” from the context menu. 4. Ensure that the listener is listening properly by running the lsnrctl command on the command line. a. Go to Start‐>All Programs‐>Accessories‐>Command Prompt Note to Windows 7 users. Make sure to run Command Prompt “As Administrator”. To do so, right click on the Command Prompt icon and choose “Run as Administrator”. b. On the command line, type the command lsnrctl status LISTENER. If your listener is listening correctly, you should see a screen similar to the following: Note the line that states that there is 1 instance running. c. If you see the line that there is 1 instance running, then you should now be able to successfully connect to Oracle using your database client.