I thought that they set network connection so that users can connect to the database. But I just noticed that the last time I transferred the database to another server, I specified "wrong" parameters there, and there were no problems connecting to the database.

In fact, I have now completely cleared the contents of these files, and I do not experience any problems connecting to the database from the application.

CodePudding user response：

• listener.ora contains the configuration for the database network listener.
• tnsnames.ora contains client-side connection descriptions. It is also found on the server, allowing the server to locate some of its own network services, or to locate remote databases for database links.

Together these files generally appear along with sqlnet.ora in the $ORACLE_HOME/network/admin directory, or in a directory specified in the TNS_ADMIN environment variable. While deleting the contents of these files may allow Oracle to assume certain defaults and continue working on some level, they often contain security-related parameters that are important for safe operation of the database in a networked environment and should not be left in this state.