How to resolve the ORA-01012 error reported by Oracle?

One common error in Oracle database is the ORA-01012 error, which indicates that the current user has timed out while executing an SQL statement. Here are some solutions:

1. Increase Timeout: You can try increasing the values of SQLNET.INBOUND_CONNECT_TIMEOUT and SQLNET.RECV_TIMEOUT parameters to extend the timeout. This can be done by adding the following lines to the sqlnet.ora file.
2. SQLNET.INBOUND_CONNECT_TIMEOUT and SQLNET.RECV_TIMEOUT both have a value of 300.
3. Check the network connection: Ensure that the network connection is stable, with no packet loss or delays.
4. To optimize SQL statements: If the execution time of SQL statements is too long, it may cause timeout errors. You can use performance analysis tools provided by Oracle, such as SQL Trace and Explain Plan, to analyze and optimize SQL statements.
5. Adding database resources: If the database resources are insufficient, it may also result in timeout errors. This issue can be resolved by increasing the CPU, memory, and disk space of the database.
6. Check the settings of the database connection pool: If using a connection pool to connect to the database, make sure that the pool’s settings are appropriate and that the connections in the pool are not being used excessively.
7. Check the database session parameters: Sometimes improper settings of session parameters can also lead to timeout errors. By checking session parameters such as IDLE_TIME, LOGICAL_READS_PER_SESSION, etc., you can troubleshoot the issue.

If the above methods do not work, it is recommended to contact Oracle support team for further assistance.