QuestSQL Optimizer.exe Entry point not found - The procedure entry point xOCIReset could not be (4230833)

The above error may occur when connecting to a database in sql optimizer if your default oracle home in the registry is obsolete or is not the same as the current home you are connecting to. That is, the occurrence of multiple homes or particularly if an older version od oracle like v8 was not properly cleaned from the registry when you upgraded.

If the default Oracle home in the registry is a valid oracle home, then you have to adjust the connection info in sql optimizer preference setting. See the following steps:
1. Open ql optimizer and don't connect.
2. Click on File menu and select Preference.
3. Click the General tab and go to Connection.
4. Click the drop down box for Oracle Home used for connection.

If the default oracle home is not valid, then delete and cleanup registry or just change the default home.