In Feburary 2016 28,
Oracle servers run both an Oracle database and listener process. One Oracle listener, which you can configure to support multiple databases, receives and manages client connection requests. If the listener receives more requests than it can handle, user requests can time out; in this case, restarting the listener will resolve the error.
Database Connection
Oracle database connection requests aren't processed unless they include authentication information such as a user name, password and the name of the Oracle service. If the authentication services aren't running or the password name is incorrect, communication efforts will fail. Similarly, if the Oracle database locks up and fails to respond to database queries, Oracle will report a failure. According to “Oracle Dba on Unix and Linux” by Michael Wessler, if the Oracle database itself crashes, the program's background processes such as PMON and SMON will terminate, and you will receive an “ORA-12637 packet receive failed” or 'TNS: packet writer failure' message.
Server & Hardware
The Tnsnames.ora file on your computer contains references to Oracle servers with which it regularly communicates. If a server name is incorrect or incomplete, Oracle can't connect to it. If the port referenced in the Tnsnames.ora file isn't open, you may see an “ORA-12637 packet receive failed” message. Router and network interface controller, or NIC, card failures also cause this problem, as can insufficient server disk input/output and system memory.
Communication
Packet communication errors can occur when a network's data traffic is so great that the time-out limit hits before your computer receives a response from the Oracle server. If the packet sizes are too large for the server to process, you can change the transport date unit, or TDU, parameters in the Tnsnames.ora file. If a network router fails and the data packets are routed to other nodes that cannot handle the load, error messages will result. You also might see errors from a malicious denial-of-service attack, or hackers turning off the Oracle listener, although the latter appears as a process failure.
In Feburary 2016 28,
Showing posts with label report. Show all posts
Showing posts with label report. Show all posts
Sunday, 28 February 2016
Wednesday, 3 February 2016
The Advantages Disadvantages of Proprietary OpenIn Feburary 2016 03,
In Feburary 2016 03,
Open-source database systems such as MySQL provide access to their source code. This means that anyone can see and edit the source code as well as using it in its compiled executable form. Proprietary databases tend to be closed source, so when you purchase a proprietary database system, for example Oracle or Microsoft Access, you are effectively purchasing the right to use the software rather than the software itself. Although the ability to access the source code used in a database system may not matter to the end user in many cases, it can affect the quality of the code because the open-source communities are able to report and in some cases fix bugs. Because an open-source database can be edited, organizations can alter it to suit their own particular needs.
Releases
Open-source systems tend to be updated more regularly than proprietary systems. This is partly because where proprietary systems are only accessed and worked on by a limited development team within the company responsible for the database product, open-source systems are worked on by an entire community, sometimes on a global scale. This means that bugs tend to be fixed faster and security issues addressed more promptly with open-source systems. Security vulnerabilities are also more visible with an open-source system than with a proprietary system, where only employees of the organization can view the code.
Costs
Proprietary database systems are charged at a commercial rate. Such rates vary for different types of account and usage. In most cases, an organization must purchase a license for each computer or account they plan on using the database system on. With an open-source database system, there is typically no cost and no restriction on the number of computers or users the database may be installed on or accessed by. The costs associated with proprietary database systems vary significantly for different system variants and account types. In some cases, the costs are so great that only large organizations can consider the database an option.
Support
Support is one of the few aspects sometimes considered an advantage with certain proprietary systems. With open-source database systems, support is usually not sourced from a single location or organization, but is sourced from the community as a whole. With a proprietary database system, customers can purchase a license with some level of support included. In such cases the customer can be more assured that the support they require will be made available to them on agreed terms, where the support with an open-source system may be less predictable.
In Feburary 2016 03,
Open-source database systems such as MySQL provide access to their source code. This means that anyone can see and edit the source code as well as using it in its compiled executable form. Proprietary databases tend to be closed source, so when you purchase a proprietary database system, for example Oracle or Microsoft Access, you are effectively purchasing the right to use the software rather than the software itself. Although the ability to access the source code used in a database system may not matter to the end user in many cases, it can affect the quality of the code because the open-source communities are able to report and in some cases fix bugs. Because an open-source database can be edited, organizations can alter it to suit their own particular needs.
Releases
Open-source systems tend to be updated more regularly than proprietary systems. This is partly because where proprietary systems are only accessed and worked on by a limited development team within the company responsible for the database product, open-source systems are worked on by an entire community, sometimes on a global scale. This means that bugs tend to be fixed faster and security issues addressed more promptly with open-source systems. Security vulnerabilities are also more visible with an open-source system than with a proprietary system, where only employees of the organization can view the code.
Costs
Proprietary database systems are charged at a commercial rate. Such rates vary for different types of account and usage. In most cases, an organization must purchase a license for each computer or account they plan on using the database system on. With an open-source database system, there is typically no cost and no restriction on the number of computers or users the database may be installed on or accessed by. The costs associated with proprietary database systems vary significantly for different system variants and account types. In some cases, the costs are so great that only large organizations can consider the database an option.
Support
Support is one of the few aspects sometimes considered an advantage with certain proprietary systems. With open-source database systems, support is usually not sourced from a single location or organization, but is sourced from the community as a whole. With a proprietary database system, customers can purchase a license with some level of support included. In such cases the customer can be more assured that the support they require will be made available to them on agreed terms, where the support with an open-source system may be less predictable.
In Feburary 2016 03,
Subscribe to:
Comments (Atom)