Solutions to some common Oracle Problems

I have previously installed a database named 10.1.0. After deleting the database named 10.1.0 and re-installing the database named 10.2.0, I started oracleoradb10g_home1tnslistener and reported an error.
Error: --------------------------- services --------------------------- cocould not start the oracleoradb10g_home1tnslistener service on local computer.
Error 1067: The process terminated unexpectedly.
--------------------------- OK ---------------------------
Solution: Go to the Registry HKEY_LOCAL_MACHINE-> system-> CurrentControlSet-> services-> oracleoradb10g_home1tnslistener-> ImagePath: C: /Oracle/product/10.1.0/db_1/bin/tnslsnr.exe found that the listening service address still points to 10.1.0 1. change the ImagePath path to 10.2.0imagepath: C:/Oracle/product/10.2.0/db_1/bin/tnslsnr.exe 2. restart oracleoradb10g_home1tnslistener.
An error occurred while connecting to the Oracle database:

It is related to the listener. ora and tnsnames. ora files. You can reconfigure the listener and local net;
You can also delete all the items in D:/Oracle/product/10.1.0/db_1/Network/admin and add them again.

Ora-01031: insufficient privileges Solution

The reason is that the user has insufficient permissions. Run the following command to grant permissions: grant debug any procedure, debug connect session to Username

1. ORA-12541: TNS: No listener
Obviously, the server listener is not started, and check whether the client IP address or port is entered correctly. Start the listener:
$ LSNRCTL start
Or
C:/LSNRCTL start

2. ORA-12500: TNS: The Listener cannot start the dedicated server process
For Windows, the Oracle instance service is not started. Start the instance service:
C:/oradim-startup-Sid myoracle

3. ORA-12535: TNS: Operation timeout
There are many reasons for this problem, but it is mainly related to the network. To solve this problem, first check whether the network between the client and the server is smooth. If the network is connected, check whether the firewalls at both ends have blocked the connection.

4. ORA-12154: TNS: unable to process service name
Check whether the entered service name is consistent with the configured service name. In addition, pay attention to the generated local service name file (for example, D:/Oracle/ora92/Network/admin/tnsnames in Windows. ora, $ ORACLE_HOME/Network/admin/tnsnames in Linux/Unix. the name of the first line of each service in ora cannot contain spaces.

5. ORA-12514: TNS: the listener process cannot parse the SERVICE_NAME given in the connection Descriptor
Open net manager, select the service name, and check whether the service name entered in the service ID column is correct. The service name must be consistent with the global database name configured by the server listener.

6. In Windows, when the listening service is started, the system prompts that the path cannot be found.
You can run the command or start the listener in the service window. The system prompts that the path cannot be found, or the listening service has an exception. Open the registry, enter the HKEY_LOCAL_MACHINE/system/current ControlSet/services/oracleorahome92tnslistener item, and check whether the ImagePath string item exists. If not, set the value to D:/Oracle/ora92/bin/tnslsnr, change the installation path values accordingly. This method is also applicable to Oracle instance services. Same as above, find items like HKEY_LOCAL_MACHINE/system/current ControlSet/services/Oracle servicemyoracle to check whether the ImagePath string item exists. If not, create a new one, set the value to D:/Oracle/ora92/binoracle. EXE myoracle.
The above are some common problems for Oracle clients to connect to the server. Of course, it cannot cover all connection exceptions. The key to solving the problem lies in the methods and ideas, rather than having fixed answers to each question.