Product:
Cognos Planning 10.1.1
Windows 2008 R2 server
Oracle database

Symptom:
When doing a GTP you get the PREPARE_ACCESS_BLOCKS to say QUEUING all the time. Why ?

Cause:
The Cognos Planning solution is setup with one JOB server and one ADMIN server.
The PREPARE ACCESS BLOCKS step is a change in the Cognos Planning application that is done from the job server. The other steps of a GTP is update of the Cognos Planning store database, that is accessed with the settings defined in Cognos Configuration. So Cognos Planning use different parts to access the databases.

Solution:
For access to oracle database to work you need to have a correct TNSNAMES.ORA file in your \oracle\client\network\admin folder on your Planning servers.

In this case the issue was solved by adding the tnsnames.ora file to the job server, there it was missing, the tnsnames.ora file was on the ADMIN server only, therefor some GTP task worked, that does not need a tnsnames.ora file.

Access defined in Cognos Configuration can be setup for oracle to direct define and access the server.