How to check if the Oracle database is running?

You can check if the Oracle database is started by using the following methods:

1. Connect to the database using the SQL*Plus command line tool.
2. Connect to the database using the sysdba account.
3. Run the following command to check the status of the database instance:
4. Retrieve the status from the v$instance view.
5. If the status is OPEN, it means the database has been started; if the status is STARTED, it means the database is currently starting; if the status is MOUNTED, it means the database instance has been mounted but not yet opened; if the status is INSTANCE MISSING, it means the database instance does not exist.
6. Check the status of the listener using the lsnrctl command line tool.
7. listener control status
8. If the status of the listener is shown as LISTENING, it means the listener has been started and is actively listening for the database instance.
9. Check the log files of the database instance.
10. The log files for Oracle database instances are typically located in the $ORACLE_HOME/diag/rdbms///trace directory. You can examine the log files containing the keyword “alert” to review relevant information regarding the database startup.

Here are some common methods to check if the Oracle database is running, you can choose the appropriate method based on your specific situation.