Oracle client tool connection database server problem summary

Summary of Oracle Client tool connection to database server problems often encounter problems that PL/SQL Developer and other Client-dependent tools cannot connect to the Oracle Database Server. So far, it has not been fully clarified. I will first post a summary of the current method, which will be improved in the future. Method 1: restart the services on the Oracle server, including the services of the database instance used by the... TNSListener. You can directly restart the service in Windows. Or (the command can be used): [plain] lsnrctl stop lsnrctl start lsnrctl reload sqlplus/as sysdba; startup; this method has been tried multiple times, but the cause is unknown and the truth is similar. Method 2: Use Net Configuration Assist to configure the server and client. The Oracle server needs to set listener (listener), and the setting result affects listener. ora (... \ db_1 \ NETWORK \ ADMIN ). The "local Net service name configuration" needs to be configured on the Client (Client), which may affect the tnsnames. ora and sqlnet. ora files. If it is an Oracle Client, the file location is... \ client_1 \ NETWORK \ ADMIN method 3: If an Oracle Client is installed, you can use the Enterprise Manager Console to add a database connection and modify tnsnames. ora file (... \ client_1 \ NETWORK \ ADMIN ). Method 4: Check whether NAMES and DIRECTORY_PATH exist in sqlnet. ora, which may be related to this. [Plain] # sqlnet. ora Network Configuration File: C: \ oracle \ product \ 10.2.0 \ db_1 \ network \ admin \ sqlnet. ora # Generated by Oracle configuration tools. # This file is actually generated by netca. but if MERs choose to # install "Software Only", this file wont exist and without the native # authentication, they will not be able to connect to the database on NT. SQLNET. AUTHENTICATION_SERVICES = (ETS) NAMES. DIRECTORY_PATH = (TNSNAMES, EZCONNECT) Note: 1. the database connection descriptor added by Enterprise Manager Console and Net Configuration Assist is different. The former is... CONNECT_DATA = (SID = ...) (SERVER = ...)..., the latter is... (SERVICENAME = ...).... 2. after deleting a connection in the Enterprise Manager Console, tnsnames. the description string in ora is not automatically deleted; after a local Net service Configuration is deleted in Net Configuration Assist, tnsnames. the corresponding description string in the ora file is automatically deleted. 3. If OWB (Oracle Warehouse Builder) is installed and configured, the file location is... \ client_1 \ NETWORK \ ADMIN.