Due to project requirements, companies need to transfer some project databases to Oracle, and it is almost all of them using SQLServer. Suddenly found, 2 to 3 years of SQL Server development and experience, in fact, did not give me how much advantage of learning Oracle, but in the first school Oracle, often wrapped around SQL Server in the brain. Many modes. Oracle is a system and a large platform, which is not just a database. So I am almost brand new whether it is, it is almost all new. Thus, only the baggage of SQL Server, to Oracle, come slowly ...
Here I record some questions when I start school Oracle. Some problems may compare some dishes, too messy, but the right to give yourself an Oracle learning notes.
By Xpilot 2004/91
1. After installing Oracle, change the Windows computer name, causing part of the Oracle third-party tool, such as: PLSQL Developer Unconventional, and prompt ORA-12541: TNS: No Listener or ORA-12547: TNS: Loss contact and other error messages .
A: From Oracle's error tips, it is to say TNS: no listener, it is estimated that some service is not started, open Windows Management Tools -> Services, one look, there is a service such as OracleraHome90 TNSListener, and error message is consistent, Basically, it is definitely the issue triggered by this service. At another look, the service did not start, and the service was started. After refreshing, the service is actually turned off immediately. Retry N times, the same result. Go to Google Search, I didn't expect this or a universal problem. One of them made a person to open the listener.ora in the installation directory. Such as: d: /oracle/ora90/neetwork/admin/listener.ora. Open the configuration file and found the following configuration information: listener = (description_list = (address_list = (address = (protocol = IPC))) (address_list = (address = (protocol = TCP) (Host = local))))))))) When seeing this row Host = Local, the problem is solved. It turned out that after a few days ago, it was also changed the computer name of Windows. The listening host name recorded in this configuration file was still the original name. This also blame, the OracleraHome90TnsListener service could not start, and immediately modified to the present The computer name, start the OracleraHome90TnsListener service, and the PL / SQL Developer is connected to the Oracle database, and cannot log in to troubleshoot.
