Explain in detail how to solve Oracle database running errors

Solution to Oracle database running errors:

Error 1: ORA-01034: ORACLE not available

After Oracle is installed and started, use sqlplus "/as sysdba" to log on. If you run any select statement, an error occurs:

Select * from dictionary

*

ERROR at line 1:

A ORA-01034: ORACLE not available

However, it is normal to use client tools such as toad!

Why does sqlplus fail?

In addition, I use:

Oracle9

Redhat as 4

Solution:

Change the environment variable ORACLE_SID of a linux User.

Error 2: ORA-27101: shared memory realm does not exist

ORA-01034 and ORA-27101 error messages when I try to connect to the database, it always displays such information, "ORA-01034-Oracle not available" and "ORA-27101-shared memory realm does not exist ".

Cannot connect to my Oracle database.

Because the firewall encountered a lot of problems, this time we should first look at it and find that there is no interception at all. After checking the listener, the database instance is also running.

The strange thing is that it was okay just now. It won't work if the machine is restarted.

Solution: the solution is not troublesome...

First, let's take a look at the ORADIM. LOG File under ORACLE_BASEORACLE_HOMEDATABASE.

If this error occurs

ORA-12640: failed to verify adapter Initialization

The problem is it.

Find the sqlnet. ora file under ORACLE_BASEORACLE_HOMENETWORKADMIN.

Change sqlnet. authentication_services = (CNT)

Sqlnet. authentication_services = (NONE)

Then manually restart your database service .. choose Start> Control Panel> Administrative Tools> service and change the startup account of this service to your account... in fact, there is no problem if you do not change it. I didn't change it ..

After reading this method, there are two possible causes of errors: Account Modification and some instance changes.

If not, restart your computer.

ERROR-ORA-12514: TNS: listener does not currently know of service requested in connect descriptor

Question about "ORA: 12541: TNS no listener"

1. Check if the listening service is unavailable.

2. Check whether the IP address and computer name have been modified.

For 2, it is generally because the IP address of the machine has changed. I have encountered this situation. The installation of oracle10g is completed in the absence of a network connection.

If the OracleDBConsole * service cannot be started after the Internet connection, my solution is to enable the service through network disconnection.

The problem is that the host information in the listener/service in the initial configuration is inconsistent with the current information. If you want to change the Host IP Address/name, you must also

Modify the corresponding configuration in oracle. Otherwise, the host cannot be started if oracle cannot be found.

Services that must be started: OracleOraDb10g_home1TNSListener (listener) and OracleService [sid]. Optional, manual

Start (because the resource consumption is high ).

Later, the OracleOraDb10g_home1TNSListener service could not be started. After google's attempt, it was originally killed when the optimization master cleared the registry. The Service Startup path should be added to the Registry.

The method is as follows:

Check whether HKEY_LOCAL_MACHINESYSTEMCurrentControlSetServicesOracleOraHome92TNSListener has a ImagePath string. If not, add one with the value .. oracleproduct10.1.0db _ 1 TNSLSNR (more than one ). similarly, Master optimization has killed VS2003. NET framework registry information, I re-installed.

In Windows, you can log on directly with the user name and password without entering the host character.