1. Check the database is up and running by
Start > run > sqlplus "as sysdba"
2. If the database is not started then start the database and look into the log files alert<SID>.log which resides in saptrace\ background directory
Identify for Oracle errors that start with "ORA"
Example 1033 .... DB_Connect Issues. i.e. The work process is unable to connect to the database.
Check the connectivity, listener status, listener.log, listener ports, listener hostnames, database startup statuses etc.
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