How to patch oracle databases

Introduction: oracle DatabasePatch Is to patch the software, which is equivalent to giving a warning, and is crucial to the stable operation of the system. This article describes in detail and systematically the classification, installation, and management of Oracle Database patches.
Most of the software patches provided by the vendor to users are compiled library functions. Therefore, installing software patches means copying these library functions to the corresponding directory and connecting them as needed. Software companies usually sort out all patches for a specific version after a period of time: Merge and integrate the patches to resolve conflicts, perform overall tests, and automatically execute file copy and connection operations, obtain a Software patch package ". Different companies use different names. Now Windows Service Pack, which is familiar to computer users, is such a patch package. The Patch Set name provided by Oracle is Patch Set, and the version after Patch Set is called Patch Set ReleasePSR ).

Oracle occasionally provides dsrs for products with standard technical support. For example, when this article is completed, the latest dsrs of Version 10.2 are 10.2.0.2, and the latest dsrs of version 10.1 are 10.1.0.5; the latest version 9.2 is probably the final version.

The patch for newly discovered bugs after installing the latest SRS will of course be included in the next one. This is a cumulative model, that is, all patches and new bugs found in the current dsrs will be included in the next dsrs. When there are several vpcs at the same time, you only need to install the latest version once. However, because of the interval between the release of the dsrs, if these bugs have a great impact on users, Oracle will also publish and provide these patches to users, these patches are called individual patches Interim Patch, one-off patch, or Patch Set Exception ). For the final patch release version, because there is no more than the next one, when you find new bugs that affect the system, individual patches become the only choice.

Oracle also regularly releases security patches, known as CPUCritical Patch Updates ). Security patches are used to fix vulnerable vulnerability of software. Such problems are not software errors and will not cause any problems during normal use. However, people with ulterior motives can bypass the security management mechanism of the database system by running well-designed code to achieve unauthorized access.

There is also a kind of patch: diagnostic patch ). As the name suggests, such patches are not used to solve the problem, but to find the cause of the problem. Such patches must be installed only when required by the Oracle Technical Support Department. Immediately uninstall the patch after obtaining the required diagnostic information.

Advantages and disadvantages timely machine selection

DBAs responsible for managing databases supporting large-scale application systems will easily understand the cost of installing software patches. When you install the dsrs, you need to stop the Database Service and shut down the database. It is difficult for many application systems to schedule such downtime. As a matter of fact, it is even more serious that the new Bug may be introduced by the installation of the SRS, which affects the normal operation of the application system. Software patches are intended to fix bugs. How can they bring new bugs? Although some are incredible, unfortunately this is a reality.

For each of the gsrs, a few hundred or more critical bugs have been fixed. Even so, some new problems will soon be found in the database after the publication of the SRS. Some of the bugs have existed before, but they have not been found before, but are occasionally detected now, or are "activated" or easily discovered due to the correction of a certain error by the SRS. However, there are some bugs that are caused by this PSR. The Oracle Technical Support Department calls it a regressing Regression ). There are two important related documents in metalink for each of the vpcs. One is "List of fixes added in XXXX", which is a List of bugs fixed by this VPC, it is a "merit book"; the other is "Known issues and alerts affecting XXXX", which is a problem found after the SRs are installed. It can be called "regret book ". Due to the complexity of large software, bugs are almost inevitable. It is important to be able to provide information in a timely manner. DBAs can make correct judgments based on their own system conditions. Readers do not have to lose confidence in Oracle database products because they know there are still bugs. The vast majority of the thousands of bugs repaired by the PSR occur in rare environments or complex combinations of several components.

If a problem occurs during the system running, the Oracle Technical Support Department or a third-party expert confirms that the cause is a Bug in the SRS. Therefore, the system must be installed as soon as possible. If the system continues to run normally, in addition, components or functions such as Logical Standby, JVM, and RAC are not used in the system. You can choose to install or not to install them.

Another factor to consider is the timing of installing patches. One of the important prerequisites for these considerations is that the system has been put into operation, worrying about the impact of "regressing" bugs on the system. If the system is still in the development and testing phase, you do not have to hesitate to install the latest dsrs and test whether the application system works properly. If any exception is found, request the Oracle Technical Support Department to check whether a new Bug is detected. If yes, ask the Oracle Technical Support Department to provide individual patches. The purpose is to test the application system on a database platform that is as stable as possible. We can generalize this patch installation policy into "patch patching without patching ".

All of the above are for the installation of the dsrs. For individual patches, it is easy to determine whether to install because the patch Fix Bug is single. Note that if several individual patches are installed on the current SRS, all individual patches need to be uninstalled after the next one is released and before the next one is installed. To facilitate management, the Oracle Technical Support Department now requires you to use the opatch tool to install and manage individual tools, and try to avoid manual file copy and other operations.

The last is the security patch installation judgment. Although the term "security vulnerabilities" seems to be very serious, it is necessary to calmly and comprehensively analyze the hazards of these vulnerabilities in the system. In fact, the danger of not installing security patches may be far less than the "Standard default" approach to consistently using usernames and passwords that everyone knows like scott/tiger.

Install the SRS

When using the oui tool to install the dsrs, you only need to make a few choices with the mouse to enter the automatic execution stage. The operation process is very simple. However, if the installation must be successful once, the operation must be completed within the limited downtime period from, when a problem occurs in the future, the possibility of this operation error will be completely ruled out, so some preparation work needs to be done before starting the oui.

1. Collect information

One of the most important documents related to this information is the software patch description, which is equivalent to the installation guide and release instructions in the Technical Manual. The file is included in the downloaded software Patch file. The file name is patchnote.htmor readme.html. Note that the Patch Set Notes found in the Software Patch file may not be the latest version. You can search for the latest version in metalink Based on the file prompts.

The other two important documents are the "merit book" and "regret book" mentioned above. You should carefully read each item in the "regret book" as opposed to "merit book. In addition, the Known Issues section of the Patch Set Notes section lists some Issues that occur after the SRs are installed.

In addition to the three main files, you should also search metalink to see if there are other technical articles related to this dsrs, find the help post sent by other users when installing this SRS or when there is a problem after the installation.

2. Make judgment

After carefully reading the collected articles, depending on the actual situation of your system, you can determine whether to install this system immediately or wait for the decision of the next one. If the installation is suspended, record the cause so that you can track the Bug fixing process in the future.

The oracle Database patch content will be explained here, and I hope it will be helpful for you to operate oracle databases.