Oracle beginners-(1)-oracleorahome90tnslistener

Due to project requirements, the company needs to migrate the database of some projects to Oracle, and almost all of them use sqlserver. Suddenly, 2 ~ Three years of experience in SQL Server development and use has not actually brought me much advantage in learning oracle. On the contrary, when I first started Oracle, it is also often plagued by many SQL Server models entangled in the brain. Oracle is a system and a huge platform. In fact, it is not just as simple as a database. Therefore, for me, management and development are almost entirely new. As a result, we can only unload the burden of sqlserver. For Oracle, please come on...

Here we will record some issues that I encountered when I started oracle. Some problems may be complicated and messy, but you have the right to take an oracle study note for yourself.

By xpilot2004/9/1

1. After installing Oracle, change the Windows computer name, resulting in some Oracle third-party tools, such as PLSQL
Developer cannot log on and prompts a solution for ORA-12541: TNS: No listener or ORA-12547: TNS: errors such as lost contact information.

A: According to the Oracle error message, TNS: No listener is used. It is estimated that a certain service has not been started. Open the windows management tool> service, there is a service such as oracleorahome90tnslistener, which is consistent with the error message. It is certainly a problem caused by this service. Again, the service was not started, and it was manually started. After refreshing, the service was automatically closed immediately. Retry n times. The result is the same. Looking at Google search, I didn't expect this to be a common problem. One person proposed to open listener. ora in the installation directory. For example, D:/Oracle/ora90/Network/admin/listener. ora.
Open the configuration file and find the following configuration information:
Listener =
(Description_list =
(Description =
(Address_list =
(Address = (Protocol = IPC) (Key = extproc0 ))
)
(Address_list =
(Address = (Protocol = TCP) (host = Local) (Port = 1521 ))
)
)
)
 
When the host = Local line is displayed, the problem is solved. It turns out that after oracle was installed a few days ago, the Windows computer name was changed, and the listening host name recorded in this configuration file is still the original name, which is no wonder, the oracleorahome90tnslistener service cannot be started. immediately change it to the current computer name. Restart the oracleorahome90tnslistener service again. PL/SQL developer connects to the Oracle database and cannot log on to the server for troubleshooting.

Summary: Oracle emphasizes manual function adjustment and places some configuration information in the configuration file. Unlike sqlserver, almost all information is stored in the registry. Of course, this is in line with the spirit of Oracle as a cross-platform database. However, it is difficult for beginners to solve this problem. Unlike SQL Server's "dummies", Oracle was almost re-installed again when the problem was solved. It seems that there were many problems such as Google analysis, and it was still time-tested.