Connection to Oracle is intermittent

I am on Toad version 2.7 and I have my Oracle connection set to connect on startup. This used to work fine on my desktop but now that I have switched to a laptop I typically have to exit Toad and restart it 3 times for it to connect. I keep getting the Could Not resolve TNS names error message on the first two times I start Toad and then on the 3rd try it connects. 3 other people I work with who got the same laptops have the same problem. These were new laptops designed for Windows 7 but have the XP operating system on it. Don’t know if that makes a difference.

That seems really strange.

What happens when you do not use auto connect and manually connect after start up? Do you get any issues there?

Also, is there anything different about your tns entry? Are you using LDAP or TNS_ADMIN? It appears that there is some timing issue here on your new laptop that was not on your previous laptop.

You could also try adding another auto connect to say the Toad Sample File. This might give you the delay needed to ‘work around’ what is occurring.


It still fails with the same message if I try to manually connect. The only way I get the connection to work is to exit Toad and start it back up again. If I set up a connect on startup for Sybase, Access or SQL server they connect just fine. Only the Oracle connection has this problem where I have to restart Toad in order to get it to connect. I will try adding the Access connection to connect on start up and see what happens.

Mnnn…I would have expected the manual connection to work. What happens if you define a Direct Connection to Oracle instead of OCI Client? I don’t prefer this connection type but in this case this is may be better.


I wanted to try that but I do not know what the SID is. I do have the fully qualified server address though.

I also tried with auto connect to access first. It connected to access just fine and still failed to connect to Oracle.

Look in your tnsnames file. You will see the SERVICE_NAME or SID entry. Use either of these for the SID for a Direct Connect.


My IT guy came and really unistalled the Oracle client by running an uninstall utility and then manually removing a whole bunch of other stuff he found online that was recomended. Then he installed the 11g client. If it creates something higher then Home_1 then you did not get everything in the uninstall. I got just Home_1 this time and everything works. ODBC or Oracle connection on startup the first time. When he started the uninstall there were still remenents of the old Ora92 install plus two 10g’s. You would think that there would be a utility to fully remove Oracle.

Thanks for your help Debbie (I did not know that I could use the Service_Name for the SID that will be useful in the future).

  • Greg

Great to hear you are up and running (and I have nothing to fix).

I’ll have to remember multiple clients have this possible reaction.