Pl/SQL, sqlplus, cannot connect to oracle

Since the oracle service is set to manual, you need to start the service each time you use it.
Today, the connection failed after the startup,
(1) command line sqlplus, connection failure prompt:
ERROR:
A ORA-01034: ORACLE not available
ORA-27101: shared memory realm does not exist
 
(2) pl/SQL connection, failed. The pop-up dialog box is displayed:
ORA-12514: TNS listener does not currently know of service requested in connect descriptor.
 
View the configuration file,
Listener. ora
Sqlnet. ora
Tnsnames. ora,
No changes.
Solution:
Restart the oracle service in the following order:
OracleServiceORCL
OracleOraDb10g_home1TNSListener
. Solve the problem.
Cause analysis:
Originally, this service was set to manual, but every time it was started, it was found that ~ Linterner. the startup status is started. (unknown reason ).
However, oracleServiceORCL must be manually started.
In this case, the listener cannot monitor the orcl service, resulting in plsql prompts and failure to identify the service.
Restart the oracle service and then start ~ Listener service to make it normal.
 
Note: The solution to this problem is personal and not representative.
 
With the dos command
Stop oracle service:
Net stop OracleOraDb10g_home1TNSListener
Net stop OracleServiceORCL
Start the oracle service:
Net start OracleServiceORCL
Net start OracleOraDb10g_home1TNSListener
Use Notepad and save it as a bat file. Double-click the file to stop the service and start the service.